Friday, September 30, 2011
Road Trip! Finale
Road Trip! Day 6
Still the morning was beautiful, and the waterfalls spectacular.
Thursday, September 29, 2011
Road Trip! Day 5 part 2
Road Trip! Day 5
Wednesday, September 28, 2011
Road Trip! Day 4
Tuesday, September 27, 2011
Road Trip! Day 3
The Sky This Week - September 29 to Thursday October 6
The First Quarter Moon is Tuesday October 4. Venus is low in the western evening twilight along with Saturn. Jupiter appears in the evening sky. Mars is visible in the morning sky and on the 29th and 1st is in the heart of the Beehive Cluster. Comet C/2009 P1 Garrad is visible in binoculars in the north-western sky.
Morning sky looking north-east as seen from Adelaide at 5:30 am local time on Sunday October 2 showing Mars and the brighter stars. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.
The First Quarter Moon is Tuesday October 4.
In the morning Jupiter is above the north-western horizon. Now is a good time to begin telescopic observation of this massive world, or follow its moons in binoculars.
Jupiter is visible in the evening sky, from about 10 pm local time on. However, for good telescopic observation Jupiter is best from 1-3 am.
Mars is low in the eastern morning sky, in the constellation of Cancer. At the beginning of the week Mars is not far from the bright star cluster the Beehive cluster. On the 30th of September and 1st of October Mars will be in the heart of the Beehive. This is best viewed with binoculars.
Comet 45P Honda is low in the morning sky, but will be very hard to see in the twilight sky without a decent telescope.
Bright white Venus is now visible low in the evening western twilight sky not far from Saturn. You will need a clear level horizon (like the ocean) to see them, and may need binoculars to pick out Saturn. Look around half an hour after sunset.
Mercury is lost in the twilight glow.
Evening sky on Sunday October 2 looking east as seen from Adelaide at 11 pm local daylight saving time in South Australia showing Jupiter. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).
Saturn is too close to the horizon to be seen without binoculars at twilight.
Despite Saturns closeness to the horizon , there are lots of interesting things in the sky to view with a telescope.If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
The location of Vesta as seen at 8:00 pm on Saturday October 1 looking north-east from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,
The asteroid Vesta is well past opposition, but is still readily visible in binoculars and is not far below the threshold of unaided eye visibility (magnitude 6.9).
Vesta starts the week above the relatively bright star Phi Capricorni, making it very easy to find. During the week it gets closer to Phi Capricorni.
Vesta is nearly at a stand still, so you may have to follow it for a few days to be sure. A chart showing Vesta's location is here.
The location of Comet C/2009 Garrad as seen at 8:00 pm Saturday October 1 looking north-west from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,
Comet C/2009 Garrad is visible in binoculars in the north-western sky, in the constellation of Hercules.
Although it has brightened substantially, it is still only a fuzzy dot at magnitude 6.9. The best views will be under dark skies, where you might spy a short faint tail. The best viewing is around 8:00 pm, when the comet is still reasonably high in the sky.
A chart showing C/2009 P1's location is here.
Printable PDF maps of the Eastern sky at 10 pm ADST, Western sky at 10 pm ADST. For further details and more information on what's up in the sky, see Southern Skywatch.
Morning sky looking north-east as seen from Adelaide at 5:30 am local time on Sunday October 2 showing Mars and the brighter stars. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.The First Quarter Moon is Tuesday October 4.
In the morning Jupiter is above the north-western horizon. Now is a good time to begin telescopic observation of this massive world, or follow its moons in binoculars.
Jupiter is visible in the evening sky, from about 10 pm local time on. However, for good telescopic observation Jupiter is best from 1-3 am.
Mars is low in the eastern morning sky, in the constellation of Cancer. At the beginning of the week Mars is not far from the bright star cluster the Beehive cluster. On the 30th of September and 1st of October Mars will be in the heart of the Beehive. This is best viewed with binoculars.
Comet 45P Honda is low in the morning sky, but will be very hard to see in the twilight sky without a decent telescope.
Bright white Venus is now visible low in the evening western twilight sky not far from Saturn. You will need a clear level horizon (like the ocean) to see them, and may need binoculars to pick out Saturn. Look around half an hour after sunset.
Mercury is lost in the twilight glow.
Evening sky on Sunday October 2 looking east as seen from Adelaide at 11 pm local daylight saving time in South Australia showing Jupiter. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).Saturn is too close to the horizon to be seen without binoculars at twilight.
Despite Saturns closeness to the horizon , there are lots of interesting things in the sky to view with a telescope.If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
The location of Vesta as seen at 8:00 pm on Saturday October 1 looking north-east from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,The asteroid Vesta is well past opposition, but is still readily visible in binoculars and is not far below the threshold of unaided eye visibility (magnitude 6.9).
Vesta starts the week above the relatively bright star Phi Capricorni, making it very easy to find. During the week it gets closer to Phi Capricorni.
Vesta is nearly at a stand still, so you may have to follow it for a few days to be sure. A chart showing Vesta's location is here.
The location of Comet C/2009 Garrad as seen at 8:00 pm Saturday October 1 looking north-west from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,Comet C/2009 Garrad is visible in binoculars in the north-western sky, in the constellation of Hercules.
Although it has brightened substantially, it is still only a fuzzy dot at magnitude 6.9. The best views will be under dark skies, where you might spy a short faint tail. The best viewing is around 8:00 pm, when the comet is still reasonably high in the sky.
A chart showing C/2009 P1's location is here.
Printable PDF maps of the Eastern sky at 10 pm ADST, Western sky at 10 pm ADST. For further details and more information on what's up in the sky, see Southern Skywatch.
Labels: weekly sky
Monday, September 26, 2011
Road Trip!
The picture is of some of the Mad Max2 cars on display at Silverton, outside Broken Hill.
Road Trip!
The picture is of some of the Mad Max2 cars on display at Silverton, outside Broken Hill.
Friday, September 23, 2011
Latest Updates on the UARS Re-entry
UARS Track as shown by the latest calculations from CalSky.A quick update on the re-entry of the Upper Atmosphere Research Satellite (UARS). CalSky is currently predicting that around September 24, 0 UT (that's 10 am AEST) the satellite will hit the atmosphere and burn up, producing a bright meteor-like train as it does.
The current ground track suggests that the satellite will burn up over the Atlantic Ocean. However, the uncertainty in it's orbit is still high, and its orbit is still evolving. You can check its progress on CalSky or Heavens Above from your site, just in case it burns up over your skies. Southern Australians might see it flash through the dawn sky around 6:00 am.
Labels: Satellite, unaided eye observation
Thursday, September 22, 2011
Comet C/2009 P1 Garrad, September 20 and 22
 |  |
Left Image: Comet 2009 P1 Garrad on 20/9/2011. Right Image: Comet Garrad on the 22/09/11. Click to embiggen. Comet C/2009 P1 Garrad imaged using the Global-Rent-a-Scope GRAS-05 instrument.
The left image was done from 120sec luminance RGB filers at 1x binning, the right luminance 120 sec 2x binning and RGB 60 secs with 2x binning. Images stretched with FITS-Liberator, aligned and cropped in ImageJ then luminance and RGB channels assembled in the GIMP, with a little contrast enhancement.
Not as good as Rolando Ligustri's image using the same exposure and binning on the GRAS-11 instrument. I still have a lot to learn about colour image processing.
Labels: astrophotography, comet, Global Rent-a-Scope
Wednesday, September 21, 2011
Carnival of Space #215 is here.
Carnival of Space #215 is now up at Cheap Astronomy. It's even got a podcast as part of the 365 days of Astronomy podcasts. Extrasolar planets feature quite a bit, and there is Moon mapping, chattering chatbot and fancy laser space drives. Blast on over and have a look.
Labels: carnival of space
Tuesday, September 20, 2011
Fireball Alert! Falling Satellite May Light Up the Sky
The Upper Atmosphere Research Satellite (UARS), is falling out of orbit. Sometime between September 22 and September 24 the satellite will hit the atmosphere and burn up, producing a bright meteor-like train as it does. Exactly when and where is not certain, as the evolution of its orbit is still ongoing. You can check its progress on CalSky or Heavens Above from your site, just in case it burns up over your skies.
The satellite is currently tumbling, and can flash as bright as Venus, and of course Thierry Legault has a picture of it.
The satellite is currently tumbling, and can flash as bright as Venus, and of course Thierry Legault has a picture of it.
Labels: Satellite
The Sky This Week -September 22 to Thursday September 29
The New Moon is Tuesday September 27. Venus is low in the western evening twilight along with Saturn. On September 28 the thin crescent Moon visits Venus and Saturn. Jupiter appears in the evening sky. Mars is visible in the morning sky and is visited by the waning Moon on September 23. Comet C/2009 P1 Garrad is visible in binoculars in the north-western sky.
Morning sky looking north-east as seen from Adelaide at 5:30 am local time on Friday September 23 showing Mars, the brighter stars and the waning Moon. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.
The New Moon is Tuesday September 27.
In the morning Jupiter is high above the north-western sky. Now is a good time to begin telescopic observation of this massive world, or follow its moons in binoculars.
Jupiter is visible in the evening sky, from about 10 pm local time on. However, for good telescopic observation Jupiter is best from 1-3 am.
Mars is low in the eastern morning sky, in the constellation of Gemini. At the beginning of the week Mars is not far from the bright stars Castor and Pollux. On Friday September 23 the waning moon is close to Mars.
Bright white Venus is now visible low in the evening western twilight sky. On Wednesday September 28 the thing crescent Moon is close to Venus and Saturn. You will need a clear level horizon (like the ocean) to see them, and may need binoculars to pick out Saturn. Look around half an hour after sunset.
Mercury is lost in the twilight glow.
Comet 45P Honda enters the morning sky, but will be very hard to see in the twilight sky without a decent telescope.
Evening sky on Wednesday September 28 looking west as seen from Adelaide at 6:41 pm local time in South Australia showing Venus, the crescent Moon and Saturn in the early twilight evening sky. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).
Saturn is still visible low in the western sky as the bright yellowish object not far from the bright star Spica. It will be lost to observation by the end of the week.
Despite Saturns closeness to the horizon , there are lots of interesting things in the sky to view with a telescope.If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
The location of Vesta as seen at 8:00 pm on Saturday September 24 looking north-east from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,
The asteroid Vesta is well past opposition, but is still readily visible in binoculars and is just below the threshold of unaided eye visibility (magnitude 6.5).
Vesta starts the week above the relatively bright star Phi Capricorni, making it very easy to find. During the week it stays roughly the same distance from Phi Capricorni.
Vesta is nearly at a stand still, so you may have to follow it for a few days to be sure. A chart showing Vesta's location is here.
The location of Comet C/2009 Garrad as seen at 8:00 pm Saturday September 24 looking north-west from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,
Comet C/2009 Garrad is visible in binoculars in the north-western sky, in the constellation of Hercules.
Although it has brightened substantially, it is still only a fuzzy dot at magnitude 6.9. The best views will be under dark skies, where you might spy a short faint tail. The best viewing is around 8:00 pm, when the comet is still high in the sky.
A chart showing C/2009 P1's location is here.
Printable PDF maps of the Eastern sky at 10 pm ADST, Western sky at 10 pm ADST. For further details and more information on what's up in the sky, see Southern Skywatch.
Morning sky looking north-east as seen from Adelaide at 5:30 am local time on Friday September 23 showing Mars, the brighter stars and the waning Moon. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.The New Moon is Tuesday September 27.
In the morning Jupiter is high above the north-western sky. Now is a good time to begin telescopic observation of this massive world, or follow its moons in binoculars.
Jupiter is visible in the evening sky, from about 10 pm local time on. However, for good telescopic observation Jupiter is best from 1-3 am.
Mars is low in the eastern morning sky, in the constellation of Gemini. At the beginning of the week Mars is not far from the bright stars Castor and Pollux. On Friday September 23 the waning moon is close to Mars.
Bright white Venus is now visible low in the evening western twilight sky. On Wednesday September 28 the thing crescent Moon is close to Venus and Saturn. You will need a clear level horizon (like the ocean) to see them, and may need binoculars to pick out Saturn. Look around half an hour after sunset.
Mercury is lost in the twilight glow.
Comet 45P Honda enters the morning sky, but will be very hard to see in the twilight sky without a decent telescope.
Evening sky on Wednesday September 28 looking west as seen from Adelaide at 6:41 pm local time in South Australia showing Venus, the crescent Moon and Saturn in the early twilight evening sky. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).Saturn is still visible low in the western sky as the bright yellowish object not far from the bright star Spica. It will be lost to observation by the end of the week.
Despite Saturns closeness to the horizon , there are lots of interesting things in the sky to view with a telescope.If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
The location of Vesta as seen at 8:00 pm on Saturday September 24 looking north-east from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,The asteroid Vesta is well past opposition, but is still readily visible in binoculars and is just below the threshold of unaided eye visibility (magnitude 6.5).
Vesta starts the week above the relatively bright star Phi Capricorni, making it very easy to find. During the week it stays roughly the same distance from Phi Capricorni.
Vesta is nearly at a stand still, so you may have to follow it for a few days to be sure. A chart showing Vesta's location is here.
The location of Comet C/2009 Garrad as seen at 8:00 pm Saturday September 24 looking north-west from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,Comet C/2009 Garrad is visible in binoculars in the north-western sky, in the constellation of Hercules.
Although it has brightened substantially, it is still only a fuzzy dot at magnitude 6.9. The best views will be under dark skies, where you might spy a short faint tail. The best viewing is around 8:00 pm, when the comet is still high in the sky.
A chart showing C/2009 P1's location is here.
Printable PDF maps of the Eastern sky at 10 pm ADST, Western sky at 10 pm ADST. For further details and more information on what's up in the sky, see Southern Skywatch.
Labels: weekly sky
Monday, September 19, 2011
Comet C/20009 P1 Garrad Septmeber 18
Comet C/2009 P1 Garrad imaged using the GRAS-05 instrument (compare with this June 29 image from GRAS-05). Click to embiggen.1 x 120 sec red, green and blue filter exposures stretched with FITS liberator then assembled into an RGB composite using the GIMP (I usually use ImageJ, but I'm trying a different approach this time). This is illustrated with the image below:
My image from August 26 taken with the Global-Rent-a-Scope G-14 instrument (1 x 120 sec red, green and blue filter exposures stretched with FITS liberator then assembled into an RGB composite using the GIMP, click to embiggen) compare this with the same image stretched with FITS liberator then assembled into an RGB composite using ImageJ.Labels: astrophotography, comet, Global Rent-a-Scope
Sunday, September 18, 2011
Venus Returns (September 2011)
Venus captured in the twilight after sunset (6:35 pm ACST, Sunday September 18), you will need to click to embiggen to see the dot that is Venus (indicated by arrow).As I noted yesterday, Venus is now visible from where I live. It's lucky I live fairly close to the ocean, as you really need to have a clear unobstructed horizon to see Venus in the twilight. However, it will climb higher in the evening sky as the month progresses, until it dominates our early evening skies.
Labels: unaided eye observation, Venus
Saturday, September 17, 2011
Evolution News and Views Fails at Exoplanets Too
Evolution News and Views noticed my previous post, and wrote a little reply. Unfortunately for them they completely missed the point, that Dembski claimed "Darwinists" were making stuff up, when there was good theoretical and (indirect) observational evidence to be confident that planets abounded in the galaxy.
The 55 Cnc system (excluding the outermost planet), 55 Cnc e is marked by the red cross near the sun. The 55 Cne system has features similar to our solar system.
Instead, they chose to focus on whether the planets we have found are habitable, which was beside the point. Guillermo Gonzalez wrote a response for them, which included this:
Distribution of orbital periods of the currently discovered exoplanets. The pink bars are "Super Jupiters" and the yellow bars are Jupiter-like planets in Jupiter period orbits.
Well, that's sort of true, but deeply misleading. When we first started looking Super Jupiters were the norm. To explain why, and why this is no longer true, I'm going to digress for a moment to explain the main methods used to find exoplanets. The first is the radial velocity method. Here the slight wobbles produced in the position of a star by the gravitational tug of an orbiting planet are detected by Doppler shift.
In the transit method, the slight dimming in the stars light as the planet passes in front of it.
Naturally, the changes are very small, right at the limit of our ability to detect them. This means that bigger planets are easier to find than smaller ones, a big planet tugs more, and can block more light. Planets that are closer to their suns are also easier to find, big close worlds tug more, and can block more light.
Distribution of exoplanets distance from their suns. Red is "Hot Jupiters", Green is multiplanet systems and blue is Jovian planets at jovian orbits.
When we first found exoplanets, back in 1995, they were jaw-dropping hot super-Jupiters closer to their suns than Mercury and screaming around their suns in a handful of days! This was a big surprise, no one expected big planets to be that close. There were also lots of weird orbits (although some of these eccentric orbits turn out to be artifacts of the way multiple stars systems orbits sum up).
Finding solar systems like ours is rather difficult even given the limitations of the telescopes we are using (which will have great difficulty finding Earth sized worlds in the first place). For example, if you were looking at the Sun for Jupiter, you would have to watch for 12 years to detect it, and you would need to wait 24 years to confirm your detection. So it is no wonder that our explanet detections up until now have been dominated by massive planets orbiting closer to their suns then Mercury is to ours.
Now with Kepler, HARPS and MOST we are seeing a wider range of solar systems, although still biased away from Earth-like worlds and solar systems like our own you can see from the diagrams above that Super Jupiters no longer predominate, and we have more normal sized planets in more normal sized orbits predominating.
While the typical extasolar system is different from our own, with more Saturn and Neptune sized worlds (quite a few are closer in, but these are orbiting smaller suns, so their relative positions aren't to far off), the way Dr. Gonzales has written his piece suggests that the typical extrasolar system is hot Jupiters in eccentric orbits. Which they are not.
We are still getting weird ones, like the planet where it rains pebbles, but even with the gross under-sampling of Earth-like worlds in the current surveys; of the 677 official and 1270 still to be confirmed planets, 54 are in the habitable zone, and 4 are Earth-like (although they are "super -Earths"). When you use these (grossly underestimated) figures to estimate the number of terrestrial worlds in their stars habitable zone (around stable, long lived stars) you get between 50 million to 50 billion habitable worlds depending on the assumptions you make.
If you take the low end estimate, and factor in habitable exomoons (shades of Avatar), then you get a figure of roughly 100 million habitable environments per galaxy which can now be used to come up with an estimate of habitable worlds in the visible universe. The number works out to 1018, or 10 million trillion.
I'll let that number sink in a bit. Now, Dr.Gonzales has written that there is a lot of work going on understanding habitable zones, which there is, but he implies that it is all shrinking the habitable zones (which it isn't). As well, some old constraints (like having a large Moon to stabilise a worlds orbit) see to be less constraining than we thought).
Even with very conservative estimates, we still have more than enough worlds in the Habitable zones of stars of our Universe to make Dembski's original statement false. As well, we have seen how once again the Discovery Institutes members try to distort facts. The DI still fails at exoplanets.
(PS, NASA's big announcement was a planet orbiting a binary star, a bit like Tatooine, if Tatooine was a frigid gas giant. It could have a habitable Moon though.)
(PPS, I'm an amateur astronomer, not a professional, but I have been using the STEREO spacecraft images to hunt for exoplanets. Boy, do I suck at it. Other teams have found an exoplanet using this system though. I'm also a member of the Planet Hunters and search the Kepler data for planetary candidates)
The 55 Cnc system (excluding the outermost planet), 55 Cnc e is marked by the red cross near the sun. The 55 Cne system has features similar to our solar system.Instead, they chose to focus on whether the planets we have found are habitable, which was beside the point. Guillermo Gonzalez wrote a response for them, which included this:
The typical exoplanetary system is very different from our Solar System. Jovian planets are being discovered in very tight or highly eccentric orbits. Jovian planets in our Solar System are characterized by large nearly circular orbits. Our Solar System looks ever more like the exception, and it is exceptional in ways that are life friendly.
Distribution of orbital periods of the currently discovered exoplanets. The pink bars are "Super Jupiters" and the yellow bars are Jupiter-like planets in Jupiter period orbits. Well, that's sort of true, but deeply misleading. When we first started looking Super Jupiters were the norm. To explain why, and why this is no longer true, I'm going to digress for a moment to explain the main methods used to find exoplanets. The first is the radial velocity method. Here the slight wobbles produced in the position of a star by the gravitational tug of an orbiting planet are detected by Doppler shift.
In the transit method, the slight dimming in the stars light as the planet passes in front of it.
Naturally, the changes are very small, right at the limit of our ability to detect them. This means that bigger planets are easier to find than smaller ones, a big planet tugs more, and can block more light. Planets that are closer to their suns are also easier to find, big close worlds tug more, and can block more light.
Distribution of exoplanets distance from their suns. Red is "Hot Jupiters", Green is multiplanet systems and blue is Jovian planets at jovian orbits. When we first found exoplanets, back in 1995, they were jaw-dropping hot super-Jupiters closer to their suns than Mercury and screaming around their suns in a handful of days! This was a big surprise, no one expected big planets to be that close. There were also lots of weird orbits (although some of these eccentric orbits turn out to be artifacts of the way multiple stars systems orbits sum up).
Finding solar systems like ours is rather difficult even given the limitations of the telescopes we are using (which will have great difficulty finding Earth sized worlds in the first place). For example, if you were looking at the Sun for Jupiter, you would have to watch for 12 years to detect it, and you would need to wait 24 years to confirm your detection. So it is no wonder that our explanet detections up until now have been dominated by massive planets orbiting closer to their suns then Mercury is to ours.
Now with Kepler, HARPS and MOST we are seeing a wider range of solar systems, although still biased away from Earth-like worlds and solar systems like our own you can see from the diagrams above that Super Jupiters no longer predominate, and we have more normal sized planets in more normal sized orbits predominating.
While the typical extasolar system is different from our own, with more Saturn and Neptune sized worlds (quite a few are closer in, but these are orbiting smaller suns, so their relative positions aren't to far off), the way Dr. Gonzales has written his piece suggests that the typical extrasolar system is hot Jupiters in eccentric orbits. Which they are not.
We are still getting weird ones, like the planet where it rains pebbles, but even with the gross under-sampling of Earth-like worlds in the current surveys; of the 677 official and 1270 still to be confirmed planets, 54 are in the habitable zone, and 4 are Earth-like (although they are "super -Earths"). When you use these (grossly underestimated) figures to estimate the number of terrestrial worlds in their stars habitable zone (around stable, long lived stars) you get between 50 million to 50 billion habitable worlds depending on the assumptions you make.
If you take the low end estimate, and factor in habitable exomoons (shades of Avatar), then you get a figure of roughly 100 million habitable environments per galaxy which can now be used to come up with an estimate of habitable worlds in the visible universe. The number works out to 1018, or 10 million trillion.
I'll let that number sink in a bit. Now, Dr.Gonzales has written that there is a lot of work going on understanding habitable zones, which there is, but he implies that it is all shrinking the habitable zones (which it isn't). As well, some old constraints (like having a large Moon to stabilise a worlds orbit) see to be less constraining than we thought).
Even with very conservative estimates, we still have more than enough worlds in the Habitable zones of stars of our Universe to make Dembski's original statement false. As well, we have seen how once again the Discovery Institutes members try to distort facts. The DI still fails at exoplanets.
(PS, NASA's big announcement was a planet orbiting a binary star, a bit like Tatooine, if Tatooine was a frigid gas giant. It could have a habitable Moon though.)
(PPS, I'm an amateur astronomer, not a professional, but I have been using the STEREO spacecraft images to hunt for exoplanets. Boy, do I suck at it. Other teams have found an exoplanet using this system though. I'm also a member of the Planet Hunters and search the Kepler data for planetary candidates)
Labels: exoplanet, extrasolar planet
I saw Venus
I walked up to the beach this evening, Venus was just visible through the thin clouds, glimmering three finger widths above the ocean horizon.
Labels: unaided eye observation, Venus
Friday, September 16, 2011
Kepler finds a World with Twin Suns
The Star Kepler16 B about to eclipse Kepler16 A as seen from Kepler 16 (A/B) b. Image simulated in Celestia.Well, it's now clear why representatives of Industrial Light and Magic (Lucas Films) were at the NASA press conference this morning. The Kepler team announced the finding of Kepler-16b, a world that circles two suns, like Tatooine from Star Wars.
Admittedly, Tatooine orbited two stars that were very like our sun, while Kepler 16-b sun's are mismatched dwarf red stars. Also, Kepler 16-b is about 2/3rds the size of Jupiter, like Saturn, and just outside it's habitable zone; more like Hoth or Bespin than the parched, rocky desert world of Tatooine.
Kepler 16 (AB) system face on.It's also not the first world in a multiple star system, although a white dwarf/pulsar system isn''t very Tatooine like. We've even found a planet in a triple star system as far back as 2005, but it is the first world that circles both stars, and both of which are at least notionally Sun-like. What does it mean overall? We originally thought that it would be difficult for planets to form around close binaries, that the dynamics of binary star formation would disrupt any protoplanets. Kepler 16 b shows that recognisable worlds can also form under these conditions, which greatly expands the number of stars which can have planets.
What does this mean for finding life? In this case Kepler 16 b is just outside the habitable zone, but a moon with a thick atmosphere might be warm enough for life. Another issue is whether the varying distances of the component suns would make planetary temperature swings too large for any form of complex life.
For Earth, the major driver of seasonal variation is the angle of inclination to the Sun, rather than the distance (northern hemisphere summer occurs at aphelion, when the earth is at it's furthest from the Sun, but Kepler 16 B comes closer and further from this world than Earth does to our Sun, and 20 day seasons could be interesting.
NASA's Kepler website has some good illustrations and animations, as well as some "Artists Concepts" with the press release. You can find more thoughts on this report at Universe Today, the Bad Astronomer, Greg Laden's blog and Dynamics of Cats. The original paper can be found here.
Of course, I've made a Celestia file. Two actually, one for the binary star system and one for the planet. I've had to guess the distance of the main star from the solar system barycenter, based on the illustration in et al., 2011, but the rest comes from the discovery paper except for the rotation period of the B component.
As usual, copy the data here to plain text files (Kepler16_binary.sts and Kepler16b.ssc), the copy both the files to the Celestia extras folder. The stars are 195 lightyears away, so in the Celestia star browser, you will have to show around 250 stars to see Kepler16 in the list. I'll have to update my Celestia Exoplanet Tour as well.
======================== Kepler16_binary.sts =========================
Replace Barycenter "Kepler16:2MASS 19161817+5145267:KIC 12644769" # replace the old star definition
{
RA 289.0750 # in degrees 19 16 18
Dec 51.7575 # in degrees +51 45 27
Distance 195.6981756 # in light years 60 pc
}
"Kepler16 A:2MASS 19161817+5145267 A:KIC 12644769 A" # Mass = 0.69 Sun masses
{
OrbitBarycenter "Kepler16"
SpectralType "K8V"
AppMag 12
Radius 451634 # in km, 0.6 Sun radii
EllipticalOrbit {
Period 0.1125 # P or T, in years
SemiMajorAxis 0.00496 # a, in AU (mass ratio MA/MB = 0.96/0.13)
Eccentricity 0.15944 #
Inclination 90.304 # in degrees
AscendingNode 0.0 # in degrees
ArgOfPericenter 263.464 # in degrees
MeanAnomaly 0.0 # in degrees
}
UniformRotation {
Period 842.4 # in hours, 35.1 days
}
}
"Kepler16 B:2MASS 19161817+5145267 B:KIC 12644769 B" # Mass = 0.33 Sun masses
{
OrbitBarycenter "Kepler16"
SpectralType "M4V"
AppMag 13
Radius 157456.08 # in km, 0.23 Sun radii
EllipticalOrbit {
Period 0.1125 # P or T, in years
SemiMajorAxis 0.22431 # a, in AU (mass ratio MA/MB = 0.96/0.13)
Eccentricity 0.15944 # guess, to be determined
Inclination 90.304 # in degrees
AscendingNode 0.0 # in degrees
ArgOfPericenter 0.0 # in degrees
MeanAnomaly 0.0 # in degrees
}
}
========================end======================================
=========================>8 Kepler16b.ssc >8==========================
"b" "Kepler16 A"
# Saturn-like world that orbits a binary star system, a bit Like Tatooine
{
Texture "exo-class4.*"
NightTexture "exo-class4night.*"
# Using Gas Giant
Mass 105.86 # M.sin(i) = 0.333 Jupiter
Radius 53890.6696 # 0.7 Jupiter radi, from paper
InfoURL "http://exoplanet.eu/planet.php?p1=Kepler-16+%28AB%29&p2=b"
EllipticalOrbit {
Period 0.626344263
SemiMajorAxis 0.7048
Eccentricity 0.0069
ArgOfPericenter 318
Inclination 90.0322
AscendingNode 0.003
MeanLongitude 106.51
#MeanAnomaly 271
}
# likely to be in captured synchronous rotation
}
AltSurface "limit of knowledge" "Kepler16 A/b"
{
Texture "extrasolar-lok.*"
}
===========================>8 cut >8============================
Labels: exoplanet, extrasolar planet, Kepler Space Telescope, spacecraft
Thursday, September 15, 2011
James Webb Telescope Funded!
Breaking News! The United States Senate has decided to fully fund the James Webb Space Telescope, and it should be set to launch in 2018. See the full story at Universe Today.
Labels: miscelaneous, spacecraft
Comet Elenin Fades Even More
The latest image of Elenin from Michael Mattiazzo (Sept 14th, taken under difficult circumstances0, show a much reduced comet which has faded to magnitude 10 or so. It is doubtful that it will be bright enough to see in the SOHO LASCO cameras. We will probably have to wait until October for powerful Earth-based telescopes to try and find if any of the comet survives.
UPDATE: Comet Al reports that Elenin is still visible in the STEREO HI1A imager, see his animation in Flickr. He estimates the comet is around magnitude 11 or so, pretty much agreeing with Michael's earth-bound estimates.
UPDATE: Comet Al reports that Elenin is still visible in the STEREO HI1A imager, see his animation in Flickr. He estimates the comet is around magnitude 11 or so, pretty much agreeing with Michael's earth-bound estimates.
Labels: comets
Wednesday, September 14, 2011
The Discovery Institute Fails at Exoplanets
KOI-701.03, an as yet unconfirmed, Earth-like world probably in the habitable zone of its Sun. KOI-703.03 visualized in Celestia (click to embiggen).Still, despite coming hard on the heels of the 50 new exoplanets found by HARPS, the existing bonanza of Kepler worlds and discovering the atmospheric composition of some exoplanets, one can hardly suppress a thrill at the prospect of learning something new about the plethora of extrasolar worlds we have found.
One wonders how William Dembski feels after proclaiming in 1992:
"Dawkins, to explain life apart from a designer, not only gives himself all the time Darwin ever wanted, but also helps himself to all the conceivable planets there might be in the observable universe (note that these are planets he must posit, since no planets outside our solar system have been observed, nor is there currently any compelling theory of planetary formation which guarantees that the observable universe is populated with planets)"Three years later the first exoplanet was confirmed, and the current count stands at 677.
Exoplanets visualized at "Data is Beautiful" for Wired.It's not the first time a pundit has been wrong, after all the philosopher Auguste Comte claimed that we would never know the composition of the stars, yet 25 years later the spectroscope revealed the elements they were made of (and in 1814 Frauenhoffer had seen the spectral lines that would reveal the stars secrets when chemistry improved).
But it's not the fact the Dembski was wrong (or Paul Nelson, who quoted him approvingly in 1993), but the way that they were wrong. The claim is that "Darwinists" posited a plethora of worlds to fulfil the needs of evolutionary theory, without any strong evidence. Yet Dembski and company couldn't be more wrong.
The 55 Cnc system (excluding the outermost planet), 55 Cnc e is marked by the red cross near the sun.Note that Dembski says "nor is there currently any compelling theory of planetary formation which guarantees that the observable universe is populated with planets". You might think this hedges his bets a bit, with the qualifications "compelling" and "guarantees", but it doesn't
By the 60's the dominant theory of planetary formation was a variant of the nebular hypothesis, which with further modification became dominant in the 1970's.
It was abundantly obvious even in the 60's that the implication of this hypothesis was that planet formation would not be a rare event (for example the RAND corporation study "Habitable Planets for Man" published in 1964 used this model as a basis for estimating the number of stars with planets).
Then there was stellar rotation. In the solar system, most of the angular momentum is in the planets, and the sun has most of the mass but just a fraction of the angular moment momentum because during planet formation the momentum of the spinning protostellar disk is transferred to the planets. Most sun-like stars have angular momentum like the Sun's suggesting that the majority of these systems had planets.
Observations in the early 80's of dusty disks around young T-Tauri stars and then dust disks around stars like Beta Pictoris were in line with the nebula hypothesis and strengthened the case that planets were common.
George Wetherill's classic paper "The Formation and Habitability of Extra-Solar Planets" did not come out until 1996, but his work in 1988, 19989 and 1991 on planet formation made scientists confident that solar system equivalents were not rare in the galaxy.
Certainly, when Dawkins published "the Blind Watchmaker" in 1986, there was a compelling theory of planetary formation, along with astromomical observations which guaranteed that there would be planets around other suns. When Dembski wrote his words in 1992, astronomers were busy designing the very instruments that would reap a harvest of extrasolar planets just a few years later.
Dembski was trying to claim that "Darwinists" make things up to bolster their arguments. If Dembski had taken a few moments to read the astronomical literature, or even asked an astronomer, he could not have made his statement.
Based on the Kepler data of 2010, we can say that around 50% of Sun-like stars have planets, and there may be at least one million Earth-like planets in habitable zones in the Milky-Way alone. And that is probably an underestimate. Some good resources are the Exoplanet encyclopaedia, Exoplanet.org (with the exoplanet data plotter) and the Habitable Zone as well as my posts on exoplanets.
Tuesday, September 13, 2011
The Sky This Week -September 15 to Thursday September 22
The Last Quarter Moon is Tuesday September 20. Jupiter appears in the evening sky and is close to the Moon on the 15th and 16th. Mars is visible in the morning sky. Saturn is low in the western evening sky. Comet C/2009 P1 Garrad is visible in binoculars in the northern sky.
Morning sky looking north-east as seen from Adelaide at 5:30 am local time on Sunday September 18 showing Mars, the brighter stars and the location of comet 45P Honda. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.
The Last Quarter Moon is Tuesday September 20.
In the morning Jupiter is high above the north-western sky. Now is a good time to begin telescopic observation of this massive world, or follow its moons in binoculars.
Jupiter is visible in the evening sky, from about 11 pm local time on. However, for good telescopic observation Jupiter is best from 2-4 am. The waning Moon visits Jupiter on Thursday the 15th and Friday the 16th.
Mars is low in the eastern sky, in the constellation of Gemini. At the beginning of the week Mars forms a rough line with the bright stars Castor and Pollux.
Bright white Venus is still lost in the twilight glow, returning to the evening sky later this month.
Mercury is lost in the twilight glow.
Comet 45P Honda enters the morning sky, but will be very hard to see in the twilight sky without a decent telescope.
Evening sky on Thursday September 16 looking east as seen from Adelaide at 11:00 pm local time in South Australia showing Jupiter in the late evening sky not far from the waning Moon. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).
Saturn is still visible low in the westen sky as the bright yellowish object not far from the bright star Spica. It is now too low in the sky for successful telescopic observation.
Despite Saturns closeness to the horizon , there are lots of interesting things in the sky to view with a telescope.If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
The location of Vesta as seen at 8:00 pm on Saturday September 17 looking north-east from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,
The asteroid Vesta is well past opposition, but is still readily visible in binoculars and is just below the threshold of unaided eye visibility (magnitude 6.5).
Vesta starts the week above from the relatively bright star Phi Capricorni, making it very easy to find. During the week it stays roughly the same distance from Phi Capricorni. Early in the week bright Moonlight will make it difficult to see, but by the weekend you should have lots of dark viewing time.
Vesta is nearly at a stand still, so you may have to folow it for a few days to be sure. A chart showing Vesta's location is here.
The location of Comet C/2009 Garrad as seen at 8:00 pm Saturday September 17 looking north from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,
Comet C/2009 Garrad is visible in binoculars in the northern sky, in the constellation of Hercules.
Although it has brightened substantially, it is still only a fuzzy dot at magnitude 6.9. The best views will be under dark skies, where you might spy a short faint tail. The best viewing is around 8:00 pm, when the comet is almost due north and highest in the sky. Early in the week the comet will be hard to see due to Moonlight, but by the weekend the skies should be dark enough to pick it up easily.
A chart showing C/2009 P1's location is here.
Printable PDF maps of the Eastern sky at 10 pm ADST, Western sky at 10 pm ADST. For further details and more information on what's up in the sky, see Southern Skywatch.
Morning sky looking north-east as seen from Adelaide at 5:30 am local time on Sunday September 18 showing Mars, the brighter stars and the location of comet 45P Honda. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.The Last Quarter Moon is Tuesday September 20.
In the morning Jupiter is high above the north-western sky. Now is a good time to begin telescopic observation of this massive world, or follow its moons in binoculars.
Jupiter is visible in the evening sky, from about 11 pm local time on. However, for good telescopic observation Jupiter is best from 2-4 am. The waning Moon visits Jupiter on Thursday the 15th and Friday the 16th.
Mars is low in the eastern sky, in the constellation of Gemini. At the beginning of the week Mars forms a rough line with the bright stars Castor and Pollux.
Bright white Venus is still lost in the twilight glow, returning to the evening sky later this month.
Mercury is lost in the twilight glow.
Comet 45P Honda enters the morning sky, but will be very hard to see in the twilight sky without a decent telescope.
Evening sky on Thursday September 16 looking east as seen from Adelaide at 11:00 pm local time in South Australia showing Jupiter in the late evening sky not far from the waning Moon. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).Saturn is still visible low in the westen sky as the bright yellowish object not far from the bright star Spica. It is now too low in the sky for successful telescopic observation.
Despite Saturns closeness to the horizon , there are lots of interesting things in the sky to view with a telescope.If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
The location of Vesta as seen at 8:00 pm on Saturday September 17 looking north-east from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,The asteroid Vesta is well past opposition, but is still readily visible in binoculars and is just below the threshold of unaided eye visibility (magnitude 6.5).
Vesta starts the week above from the relatively bright star Phi Capricorni, making it very easy to find. During the week it stays roughly the same distance from Phi Capricorni. Early in the week bright Moonlight will make it difficult to see, but by the weekend you should have lots of dark viewing time.
Vesta is nearly at a stand still, so you may have to folow it for a few days to be sure. A chart showing Vesta's location is here.
The location of Comet C/2009 Garrad as seen at 8:00 pm Saturday September 17 looking north from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,Comet C/2009 Garrad is visible in binoculars in the northern sky, in the constellation of Hercules.
Although it has brightened substantially, it is still only a fuzzy dot at magnitude 6.9. The best views will be under dark skies, where you might spy a short faint tail. The best viewing is around 8:00 pm, when the comet is almost due north and highest in the sky. Early in the week the comet will be hard to see due to Moonlight, but by the weekend the skies should be dark enough to pick it up easily.
A chart showing C/2009 P1's location is here.
Printable PDF maps of the Eastern sky at 10 pm ADST, Western sky at 10 pm ADST. For further details and more information on what's up in the sky, see Southern Skywatch.
Labels: weekly sky
Monday, September 12, 2011
Finding the bright Supernova 2011fe in M101
North-western sky as seen form around latitude 30 deg north at astronomical twilight (an hour and a half after sunset). M101, which hosts the supernova is above the handle of the big dipper.With Supernova 2011fe being exclusively a northern hemisphere object, I have neglected the basic "look here" type posts I normally do.
However, despite this blog being largely about observing from the southern hemisphere, with added exoplanets, most of my readers are from the US (thank you, comet Elenin), so I'm doing a finding the supernova post just for you.
Now Supernova 2011fe is the brightest supernova in the past 20 years, however it's currently around magnitude 10, which makes it very faint from our pespective (the limit anyone can see under dark skies with ideal eyesight is magnitude 6.5). You will need a small telescope or dark skies and good, tripod mounted binoculars to see it.
Approximate binocular view of M101 (Click to embiggen).A big problem at the moment is Moonlight, for the next day or so bright Moonlight will mean that the supernova (and its host galaxy M101) will be effectively invisible in binoculars and small telescopes. You will have to wait until the Moon is below the horizon (September 15) to see them.
The other problem is that M101 sets not too long after twilight, so you have about 2 hours where it is high enough above the murk around the horizon to see.
M101 is a faint patch of light in binoculars, despite its listed brightness of magnitude 7.7, it is a diffuse object, so rather dim, it may look like no more than a fuzzy dot. It will look better in a smal telescope, but will still be a fuzzy patch.
Once you have it, the star within the fuzzy dot is the supernova. Happy supernova hunting!
Labels: supernova
Carnival of Space #214
Welcome to the Downunder Edition of Carnival of Space 214
We have lots of good stories for you this week.
Near Earth:
Solar System
Deep Space
Cosmos
We have lots of good stories for you this week.
Near Earth:- The Space Show welcomes Dr. Jeff Bell back for a two hour plus discussion regarding the retirement of the space shuttle.
- Gene Roddenberry's son tells Discovery News about how his father's vision inspires society, and Discovery News talks to Richard Obousy about how Star Trek inspired him to formulate the science behind the warp drive.
- Cheap Astronomy chats to the Ordinary Guy from the Brains Matter podcast about astronomy, science and saving the world.
- Vintage Space has a history of the real Apollo 18 mission.
- The AIAA has posted the rules to this year's Cessna/Raytheon Missile Systems Student Design/Build/Fly competition.
- This post from Vega00 explains how to create a time-lapse easily with VirtualDub [In Spanish]
- The Next Big Future explains how Russia is trying to get its rockets flying again so that the Space Station does not have to be evacuated. They also describe how the Blue Origin rocket had a crash, but there are images of what the secret rocket looks like in flight. They they show Electric solar wind sail videos of components in operation. A 10 meter test tether should be sent to space in 2012.
- The Meridian Journal talks about the new images taken by the Lunar Reconnaissance Orbiter show the Apollo landing sites on the Moon in the greatest detail yet. So does Universe Today.
- ZME science reports that the Royal Observatory gives out their annual awards for astronomy photography, and the pictures are amazing.
Solar System
- Centauri Dreams ponders the possibilities of moving asteroids in their orbits, and wonders, as did earlier writers, whether it's a good idea, even if the windfall from mining could be immense.
Deep Space- Chandra Finds Nearest Pair Of Supermassive Black Holes.
- The Next Big Future reports how the Kepler space telescope detected an exoplanet indirectly by detecting the gravitational effect on a visible exoplanet.
- StarryCritters explores a protoplanetary nebula shaped like a starfish or dragonfly.
- A transient Nova in Scorpius was discovered "twice" 92 mins apart by separate observers, interestingly it was brighter than the Supernova our northern cousins have been getting excited about, but appears to have faded slightly already. Details are still emerging about the discovery - Astroswanny has photos. It expected to be announced as a Type Fe II Nova.
Cosmos
- Atra Materia looks at the latest information about dark energy.
- TheSpacewriter muses on measuring the universe.
Labels: carnival of space
Sunday, September 11, 2011
Comet Elenin Passes Perihelion ...
.. and nothing happened. To complement Michael Mattiazzo's recent images, here's image taken on Sept 7 by Jonh Glossop http://www.iceinspace.com.au/forum/attachment_browse.php?a=100255. Now were are waiting for the remnants of the comet to enter the SOHO C3 imager.
Labels: comet
Saturday, September 10, 2011
And Meanwhile ...
... comet 213P van Ness has fragmented again, two new comets have been discovered and there is a new Nova in Scorpius.
Not to mention that GRAIL made it into orbit okay, and the newly discovered planet in a habitable zone. I just don't have time too keep up (I still have to process my images of C/2009 P1 Garrad and Vesta and the latest STEREO images).
Not to mention that GRAIL made it into orbit okay, and the newly discovered planet in a habitable zone. I just don't have time too keep up (I still have to process my images of C/2009 P1 Garrad and Vesta and the latest STEREO images).
Labels: comet, exoplanet, miscelaneous, news, nova
Comet Elenin by Radar
Leonid Elenin reports of the first radio telescope observation of comet C/2010 X1 Elenin. Radar spectroscopy did not pick up any signature of water vapour from the comet, suggesting that it has well and truly broken up. We will have to wait for Comet Elenin to come into range of the Arecibo radio telescope and the SOHO spacecraft to learn more.
In the meantime, Michael Mattiazzo's latest Elenin images show it fading and becoming more tenuous than before.
In the meantime, Michael Mattiazzo's latest Elenin images show it fading and becoming more tenuous than before.
Labels: astrophotography, comet
Of Various Astronomcial Photography Competitions
Okay, so I am very, very late on this, but the David Main Awards for Australian astrophotography have been out since July. You can see the winning entries here (scroll down, it's worth it), as well as dates that the winning images will be displayed at various cities as it travels around Australia.
Note the winner of the Junior award, her image was featured first on this very blog! Let's hope she goes on to to do more outstanding astrophotography.
Universe Today has images of the winning entries for Astrophotographer of the Year, which is run by the Royal Observatory Greenwich and Sky at Night Magazine. See the winners here, they are stunning. There are a lot more images at the Astronomy Photographer of the Year Flickr site .
Note the winner of the Junior award, her image was featured first on this very blog! Let's hope she goes on to to do more outstanding astrophotography.
Universe Today has images of the winning entries for Astrophotographer of the Year, which is run by the Royal Observatory Greenwich and Sky at Night Magazine. See the winners here, they are stunning. There are a lot more images at the Astronomy Photographer of the Year Flickr site .
Labels: astrophotography
September 10, Sun Very Active, Possibility of Aurora,
Sunspots on September 9, image credit SOHO/NASA/ESA.The Sun has been readily blasting off powerful flares for the past week, with particularly powerful X class flare on the 8th (some great images at Spaceweather) .
Most of these are from sunspot 1283 (cluster at far right on the image). These have not translated into aurora, not really being directed at Earth.
There is an geomagnetic alert for Australia tonight from a more Earth directed coronal mass ejection, whether this will translate into either a geomagnetic storm or aurora is hard to say.
Certainly people in Tasmania and Southern New Zealand should be on the lookout for aurora this evening (Saturday September 10), but the bright Moonlight will make observing any aura difficult.
UPDATE: In the northern hemisphere this CME event has sparked fantastic aurora to relatively low latitudes (see this Spaceweather report with a great picture gallery), Here in the southern hemisphere the IPS merely forecasts minor storm periods.)
Labels: aurora
Thursday, September 08, 2011
Supernova 2011fe in M101 Nearing or at Maximum Brightness
Supernova 2011fe imaged using Global-ret-a-scope GRAS_05 on August 30 (click to embiggen)Supernova 2011fe in M101 has been brightening considerably, and is nearing, or may be already at, it’s maximum brightness. If you have M101 reasonably high in your night sky, you should be able to see the supernova in binoculars. Sadly, this supernova can't be seen from most of Australia.
Labels: Global Rent-a-Scope, supernova
Wednesday, September 07, 2011
Carnival of Space #213 is here.
Carnival of Space #213 is now up at Weird Warp. There is the probability of finding Earth-like planets, reactors in space, olar sail deveopments and much, much more. Trim your sails and head on over.
Labels: carnival of space
The Sky This Week -September 8 to Thursday September 15
The Full Moon is Monday September 12. Jupiter appears in the evening sky and is close to the Moon on the 15th. Mars is visible in the morning sky. Saturn is low in the western evening sky. Comet C/2009 P1 Garrad is visible in binoculars in the northern sky.
Morning sky looking north-east as seen from Adelaide at 5:30 am local time on Sunday September 4 showing Mars, the brighter stars and the location of comet 485P Honda. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.
The Full Moon is Monday September 12.
In the morning Jupiter is high above the north-western ern sky. Now is a good time to begin telescopic observation of this massive world, or follow its moons in binoculars.
Jupiter is visible in the evening sky, from about 11 pm local time on. However, for good telescopic observation Jupiter is best from 2-4 am. The waning Moon visits Jupiter on Thursday the 15th.
Mars is low in the eastern sky, in the constellation of Gemini. From the 11th to the 15th Mars froms a rough line with the bright stars Castor and Pollux.
Bright white Venus is still lost in the twilight glow, returning to the evening sky later this month.
Mercury is quite close to the horizon in the morning skies. Mercury starts the week close to the bright star Regulus, although you will need a clear level horizon to see it. By the end of the week Mercury is lost in the twilight glow.
Comet 45P Honda enters the morning sky, but will be very hard to see in the twlight sky without a decent telescope.
Evening sky on Thursday September 15 looking east as seen from Adelaide at 11:00 pm local time in South Australia showing Jupiter in the late evening sky not far from the waning Moon. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).
Saturn is still visible low in the westen sky as the bright yellowish object not far from the bright star Spica. It is now too low in the sky for successful telescopic observation.
Despite Saturns closeness to the horizon , if you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
The location of Vesta as seen at 8:00 pm on Saturday September 10 looking north-east from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,
The asteroid Vesta is now past opposition, but is still readily visible in binoculars and is just below the threshold of unaided eye visibility (magnitude 6.5).
Vesta starts the week not far from the relatively bright star Phi Capricorni, making it very easy to find. During the week it moves away from Phi Capricorni. Later in the week bright Moonlight will make it difficult to see.
Vesta moves significantly night to night, so will be easy to follow. A chart showing Vesta's location is here.
The location of Comet C/2009 Garrad as seen at 8:00 pm Saturday September 10 looking north from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,
Comet C/2009 Garrad is visible in binoculars in the northern sky, in the constellation of Sagitta, the Arrow.
Although it has brightened substantially, it is still only a fuzzy dot at magnitude 7. The best views will be under dark skies, where you might spy a short faint tail. The best viewing is around 8:00 pm, when the comet is almost due north and highest in the sky. During the week the comet will become harder to see as the Moonlight brigtens.
A chart showing C/2009 P1's location is here.
Printable PDF maps of the Eastern sky at 10 pm ADST, Western sky at 10 pm ADST. For further details and more information on what's up in the sky, see Southern Skywatch.
Morning sky looking north-east as seen from Adelaide at 5:30 am local time on Sunday September 4 showing Mars, the brighter stars and the location of comet 485P Honda. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.The Full Moon is Monday September 12.
In the morning Jupiter is high above the north-western ern sky. Now is a good time to begin telescopic observation of this massive world, or follow its moons in binoculars.
Jupiter is visible in the evening sky, from about 11 pm local time on. However, for good telescopic observation Jupiter is best from 2-4 am. The waning Moon visits Jupiter on Thursday the 15th.
Mars is low in the eastern sky, in the constellation of Gemini. From the 11th to the 15th Mars froms a rough line with the bright stars Castor and Pollux.
Bright white Venus is still lost in the twilight glow, returning to the evening sky later this month.
Mercury is quite close to the horizon in the morning skies. Mercury starts the week close to the bright star Regulus, although you will need a clear level horizon to see it. By the end of the week Mercury is lost in the twilight glow.
Comet 45P Honda enters the morning sky, but will be very hard to see in the twlight sky without a decent telescope.
Evening sky on Thursday September 15 looking east as seen from Adelaide at 11:00 pm local time in South Australia showing Jupiter in the late evening sky not far from the waning Moon. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).Saturn is still visible low in the westen sky as the bright yellowish object not far from the bright star Spica. It is now too low in the sky for successful telescopic observation.
Despite Saturns closeness to the horizon , if you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.
The location of Vesta as seen at 8:00 pm on Saturday September 10 looking north-east from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,The asteroid Vesta is now past opposition, but is still readily visible in binoculars and is just below the threshold of unaided eye visibility (magnitude 6.5).
Vesta starts the week not far from the relatively bright star Phi Capricorni, making it very easy to find. During the week it moves away from Phi Capricorni. Later in the week bright Moonlight will make it difficult to see.
Vesta moves significantly night to night, so will be easy to follow. A chart showing Vesta's location is here.
The location of Comet C/2009 Garrad as seen at 8:00 pm Saturday September 10 looking north from Adelaide, similar views will be seen at equivalent local times elsewhere. Click to embiggen,Comet C/2009 Garrad is visible in binoculars in the northern sky, in the constellation of Sagitta, the Arrow.
Although it has brightened substantially, it is still only a fuzzy dot at magnitude 7. The best views will be under dark skies, where you might spy a short faint tail. The best viewing is around 8:00 pm, when the comet is almost due north and highest in the sky. During the week the comet will become harder to see as the Moonlight brigtens.
A chart showing C/2009 P1's location is here.
Printable PDF maps of the Eastern sky at 10 pm ADST, Western sky at 10 pm ADST. For further details and more information on what's up in the sky, see Southern Skywatch.
Labels: weekly sky
Monday, September 05, 2011
For the Astronomer who has Everything (Part 2)
 |  |
| My fathers day Dalek T-Shirt illuminated by my LED cap. I have the best family in the world | And the worst parrot, I used my LED cap to illuminate and repair parrot chewed wires to make the computer work again |
Labels: home life, miscelaneous
Sunday, September 04, 2011
Leonid Elenin on the Break-up of Comet Elenin
Go here for http://spaceobs.org/en/2011/09/03/comet-elenin-the-final-prospect/ Leonid Elenin discussing the break-up of his comet and the latest observing prospects.
Labels: comet
For the Astronomer who has Everything
Friday, September 02, 2011
Will the Fragments of Comet Elenin Rain Doom upon the Earth? (No, but You Knew That)
The disintegration of comet 73P (not Elenin). Image Source wikipedia commons.
Now that Elenin is disintegrating, some people are worried that chunks of the disintegrating comet will hit Earth. But what people fail to realise is that space is really, really, REALLY big.
That sounds a bit patronising, but is actually very hard to get a good grip on the distances involved, the mind reels from the vastness.
To get a feel for what the distances are like, try this demonstration.
Get a pea, a peppercorn and a mustard seed (or objects with those rough general dimensions). Put the pea on your back doorstep, that’s earth. With a ruler measure out 384 mm and put the peppercorn 384 mm away from the pea, that’s the Moon. Now pace out 35 meters (yes, you read that right 35 meters), that represents the closest approach of Elenin to the earth. Put the mustard seed there (it’s actually much bigger than Elenin would be at that scale, but it’s the smallest object that you can actually work with).
Now, get a hammer and smoosh the mustard seed to a powder. Look at how far the powder flies from the mustard seed*; look back the 35 meters to the Earth.
Any questions?
* When comets break up, most of the material stays on much the same orbit as the parent comet (see image of 73P above as an example). Over the years it will spread out a bit, but for Elenin the material won’t move far enough away over the next few weeks to register on our model. Even if Elenin had undergone a DeathStar like dramatic explosion, rather than the gentle sigh and crumbling, the vast distances involved would mean that the material would not impact the earth.
Labels: comet
Click to read about or order
Click to read about or order
Click to read about or order
Click to read about or order
