Wednesday, May 31, 2006
Radio Meteor Alert! Do we have a 73P meteor shower
Tuesday, May 30, 2006
31 May, Moonight, Mars and Meteors from 73P?
As noted by Tom, the night of Wednesday May 31 is the time of closest apporach of the largest fragment of 73P. The t-Herculid meteor shower is associated with comet 73P, so will we get a decent meteor shower from it? Probably not. Because the comet is relatively so far away (around 0.4 au) it is very unlikely we will see much at all, perhaps 1-2 meteors per hour. In the Southern hemisphere, the radiant (which is near the fouth magnitude star delta Bootis (cirlced in the image above)) never gets very far above the horizon (around 25 deg at Adelaides latitude), so we are likely to see even fewer meteors. Then again, we have been surprised before, so why not take a look. While the radiant isn't high in the Southen hemisphere, in Australia at around 11 pm AEST the comet will pass through earths orbital plane, so this should be the time of maximum meteors (the Americas and Europe miss out on the plane crossing to a large extent). See this interesting paper on the t-Herculids. The best times for meteor showers for 73P is 2022 and 2049. Here's a nice image of 73P from earlier in the month.
(Click to enlarge: northwestern horizon at 6:00 pm ACST, similar views will be seen at similar local times elsewhere in the Southern Hemisphere) 73P meteors aren't the only reason to go out on Wednesday May 31. In the early evening, Mars is close to the crescent Moon. With Saturn nearby, and Castor and Pollux below, this will be an attractive (and photogenic) time to view the sky. Saturn is on the border of the Beehive cluster, and looks very attractive in binoculars. This is the furst step in an array of planetary alignments that I will write about tomorrow.
Monday, May 29, 2006
Another great shot of Venus
There are some great opportunities for seeing the Moon and planets line up in the next few weeks, so limber your cameras up folks. Tommorow night (Wednesday May 31) the crescent Moon is next to Mars and Saturn is just above them. On June 28, Mercury, Mars the crescent Moon and Saturn are all strung out in a line reasonably close together. And that's not all. I'll post about some amazing close encounters over the next few days.
Sunday, May 28, 2006
HD 69830's planets in Celestia
If you haven't read Stuart's post on the recent discovery of three Neptune size exoplanets, go over there now. I've made a Celestia file for this solar system (minus the asteroid belt we know is around it). You can download the SSC file here. Note that Version 1.4 of Celestia uses different image file descriptions for several planets and asteroids compared to the early versions. All my previous files were set up for early version, so UB313 and the new Plutonian moons etc come out as blank spheres. I've fixed Sylvia and the Plutonian Moons, I'll work my way through the others eventually (the old versions can be found here and here for people running Celestia 1.1-1.3).
(Image Credit ESO [click to enlarge]) Anyway, back to the planets. This image is an "artistic rendering" from the ESO. Note that the images of the planets are greatly exaggerated in size compared to their actually sizes from the point of view (the Celestia image shows the correct observed sizes from a given vantage point). The size and density of the asteroid belt is also exaggerated. But hey, the point of these things is to capture peoples imaginations. The ESO site also has a nice press release on the planets, as well as some cool animations.
(Image Credit ESO [click to enlarge]) People are really excited as at least one of these planets is in the putative habitable zone of liquid water. While they are not Earth-like in any real sense, they are the first good evidence that non-Jovian planets can end up in solar system type orbits. However, they may much up our understanding of how planets form. The hot superjovians completely messed up our first models, there was no way we could see that jovian planets could from so close to a sun. Now we have a migration model, where Large planets form far out from the star, and migrate in. These planets are thought to have migrated in after forming, but at least two have to migrate through the asteroid belt. While they won't have as big an effect as Jovians, I have a hard time understanding how migrating Neptunian worlds will leave a susbtantial asteroid belt (Stuart, Megan any ideas?).
Saturday, May 27, 2006
Also had a look for 73P, guide stars down to mag 7.0 visible, couldn't see nary a comet though.
Friday, May 26, 2006
73P is fading now. As the Moon has left the morning sky, it is sufficently dark to make seeing 73P much easier, but it is closer to the threshold of unaided eye vision. I've updated my binocular spotters maps to make it easier to find. We in the Southern Hemisphere now have the best view of the comet.
Here is a nice shot of jets from 73P-C, and a spectactular shot of 73P-B.
Where's the kaboom? There was supposed to be an earth-shattering kaboom!
Thursday, May 25, 2006
Views of Venus
This is a closeup view of the Moon and Venus on the 24th. You can just see the maria in the Earthshine of the cresent. (click to enlarge)
This one, taken on Thursday 25, with the Moon just two days from New, shows the Earthshine and maria very nicely. (click to enlarge) The image is sideways, to make it easier to view.
Wednesday, May 24, 2006
The world will not end this Thursday.
Monday, May 22, 2006
Sunday, May 21, 2006
Well, comet 73P should start fading over the next week. I still haven't seen it. Cloud has been relentless here. We can have quite clear sunny days, then the cloud moves in as soon as I think of getting the scope out.
73P has been displaying more exciting behaviour. Here are some of the latest images of 73P-B, a nice summary of recent activity from Dr. P. Clay Sherrod, an S-band filter image showing knots and fragments and twin jets, a fanttastic animation from the same group, finally some recent images of both B and C.
Thursday, May 18, 2006
Coronal hole approaching.
73P-C in outburst
Wednesday, May 17, 2006
73P at its brightest
I've been off air for a bit of a while as I write lectures and mark student papers, I'm also trying to finish my Sky&Space contribution, whihc is WAY overdue. But the next few days will be when the 73P frgments are at their brightest. I've been pretty well clouded out, but a couple of mornings ago the sky was clear ... and I saw nothing. Well, I thought I could see a faint furry smudge with averted vision in binoculars, but the Moonlight just washed everything else out. Othere people we reprting seeing 73P quite easily under Moonlight, so don't be discouraged by my lack of success.
73P-B is in outburst again, and it appears another large fragment has detached, see images here, here, here and here. A very nice animation is available to the patient here.
Did you see the occultation of Antares?
Did a piece of space junk land in Queensland?
Mercury is the bright rayed object just near the Solar occultatin disk. The long rays are artefacts of the imaging system. A great movies of Mercury approaching the Sun is available in low resolution (256 Kb) and high resolution (1.6 Mb). Later this year Mercury will pass across the face of the Sun in a rare transit.
Friday, May 12, 2006
Occultation of Antares 14-15 May
Spitzer Space Telescope looks at 73P
This amazing image is the infrared Spitzer Space Telescope's image of Comet 73P. The fragments of the comet stand out quite clearly in this infrared image, taken over 21 hours. The the line bridging the fragments is the dust trail of the comet, invisible in normal light, but readily aparent in infrared. Read the media relase here, or download medium or high (4.3Mb) TIFF images.
Astronomy Picture of the Day has yet another image of 73P-C and the Ring Nebula.
Wednesday, May 10, 2006
73P-B is in outburst again, it is currently magnitude 5 (which is bright for what it was usupposed to be), out shining 73P-C which is only magnitude 6 (73P-C should be two magnitudes brighter than B). Recent pictures are here and here. A magnificent animation of 73P-C passing by the ring nebula is here. (via the Badastronomer).
You just KNOW this post will be about 73P
Tuesday, May 09, 2006
73P-B, spectacular jets and a close encounter with M57
73P-C is not as dramatic, but it did pass close to M57, the Ring Nebula, recently, here is a very nice image from Raymon Naves and another very nice one from Gianluca Masi.
73P-C is reported at magnitude 6.0-6.2, 73P-B at magnitude 6.5-6.8.
Sunday, May 07, 2006
For the last time, 73P will NOT hit the earth
Update: A NASA article about 73P failing to hit Earth is here.
73P speeds up
73P is now picking up pace as closest approach looms (and you have to get up earlier in the morning to see it), it's possible to see it move during an observing session. There are still plenty of amazing shots of the comet, especially the new break-up of 73P-B from Carl Hergenrother, Dave Strange, Clay Sherrod and Gianaluci Masi and co.
Saturday, May 06, 2006
Titan: The Movie
Remember the thrilling pictures from the Hyugens Lander as it approached Titan's surface? Well, the clever people from the Hyugens mission have put together a stunning* Quicktime Video from the lander images. You can have a video with narration (15.4 Mb) which swoops down to the surface or a video where datasets are represented by chimes and clicks and the instrumentation results are displayed at the same time (11 Mb, it's rather charming).
Other Titan related news is that the moon appears to be covered in giant sand dunes composed of particle of ice and organics.
A tip of the hat to Nick Matzke of the Panda's Thumb for the heads up.
*Yes, I know I use "stunning" a lot, but these videos are definitely worthy of that appellation.
Catch the Jodcast
Jupiter Observed at opposition.
You can see quite a bit of detail in the enlarged images, which is pretty amazing given this is taken with an old webcam on a 4" unguided Newtonian. The top image shows some really nice cloud detail (when you click on it and get the enlarged view).
I didn't get to see the new "son of the Great Red Spot", but new Hubble images have been released of it.
Friday, May 05, 2006
Look at Jupiter tonight
Jupiter is at opposition tonight, when it is at it's biggest and brightest. Oppositions of Jupiter don't get as much press as oppositions of Mars, probably because a) Mars holds such iconic staus in our imaginations, and b) even at it's furthest, Jupiter is still big and bright.
None the less, Jupiter and its Moons will be excellent objects tonight and for the rest of the month in binoculars or a small telescope (if you have a big telescope, then it goes wihout saying Jupiter will be good). SO do your level best to get to a telescope soon. Jupiter is failry easy to recognise, in the veneing, it is the brightest object in the eastern sky. Startlingly bright, although not as bright as Venus. Jupiter is just in from of the "T" shaped group of stars that mark the head of the constelation of Scorpius, the scorpio, making that area of the sky rather attractive.
Tonight there is a dual transit and shadow transit of Io, starting at 17:20 and finishing at 21:20 tonight (ACST), but you will need a medreate sized telescope to see this.
Thursday, May 04, 2006
Morning Meteors, Saturday May 6
The Eta (n) Aquariids is a very reliable southern hemisphere shower. Unfortunately, it is a reliable morning shower. You have to get up around 3.30-4.00 am to see it at its best. Well, you can also check out comet 73P to the north, and Venus as well at this hour. At 4.00 am the radiant of the shower (where the meteors appear to come from, marked by Radiant ETA on the map) is about 24 dgerees (four handsapns) above the easterm horizon. The Eta Aquariids is associated with Halleys comet, and consistes of fast, often bright meteors, some with persistant trails. Although the actual peak rate is around 2.00 pm Saturday in Australia, the best time to look is around 4.00 am Staurday morning. You can probably expect to see ameteor every 3 minutes.
Numerology, sort of.
Still more 73P Hijinks!
73P-C is reported as visible to the unaided eye under dark skies (magnitude esitimates range from 6.0-6.3), and 73P-B has been reported as visible with averted vision under dark skies (mag range from 6.5 to 6.8).
Tuesday, May 02, 2006
May Southern Skywatch available
The May Southern Skywatch is out now. What's up this month? The opposition of Jupiter, unaided eye Callisto, unaided eye 73P, and an occultation of Antares amongst other things.