Friday, June 24, 2011
Coming Close to Vesta
Navigation camera movie of the approach to Vesta (Video Credit, NASA/JPL-Caltech/UCLA/MPS/DLR/PSI).
Dawn and Hubble images of Vesta compared (Image Credit, NASA/JPL-Caltech/UCLA/MPS/DLR/PSI).The Dawn spacecraft is closing in on the asteroid Vesta. It should reach Vesta in early-Mid July and orbit the asteroid for a year, mapping and exploring it before visiting Ceres. Still over 180,000 Km away, this is the best views of this massive asteroid we have ever had.
From Earth, Vesta is a dot, but you can readily see it in binoculars, so it might be worth watching this world while the Dawn spacecraft approaches.
Labels: sphttp://www.blogger.com/img/blank.gifacecraft, Vesta
Saturday, February 20, 2010
Opposition of Vesta from Mars
Left Panel, asteroid Vesta as seen from Mars on the 11th of February (for Earth reference see here), Right Panel, Vesta as seen from Mars at the time of Opposition on Mars on & May 2010. Image visualized in Stellarium, location approximately latitude of Adelaide on Mars (as always, click to embiggen).
In my series of posts about seeing things from other worlds, (opposition of Mars from Mars and Venus), I'm having a look at the opposition of the asteroid Vesta. (My photographs and sketches here and here) Vesta is just visible to the unaided eye at the moment (if you are some place far from city lights). Mars is much closer to Vesta than Earth, how would Vesta look there?
Well, it's still a featureless dot, but it's much brighter. At opposition, it's a bit under magnitude 5, which means you could see it from the suburbs (if you had suburbs on Mars). However, as Mars's orbital plane is a bit angled to that of Earth's, Mars doesn't see Vesta glide between 40 and gamma Leonis, but sees it not far from the bright star Denebola in the tail of the Lion, rather than in the Head, as we see it.
Vesta's position in relation to Earth and Mars on 22 February and & March 2010, respectively. Mars's opposition of Vesta is much later than ours, as It has to catch up with the slower moving Vesta, while speedy Earth has already passed it by. Orbits visualised in Celestia.
Labels: asteroids, Mars, Opposition, stellarium, Vesta
Friday, February 19, 2010
Vesta Again
Vesta near gamma and 40 Leonis on 18 February as imaged with my Canon IXUS (ASA 800, 1.3 sec exposure) attached to my 4" reflector with the 20mm eyepiece using my camera adaptor. This is an overlay of two images taken an hour apart, the image is upside down and back to front from the point of view of a binocular observer.You can see Vesta has moved a little bit over the hour. Compare this to the images taken with the 8" and webcam, where you can see much more movement, due to the larger magnification, and my sketches. Click to embiggen.
The location of Vesta is actually a bit distorted, due to images taken in different parts of the eyepiece field, and the rotation of the field of viw over the hour.
Labels: astrophotography, Opposition, Vesta
Wednesday, February 17, 2010
Vesta flys by 40 Leonis
Last night (16 February, 2010), the Asteroid Vesta (the dot with the "v" next to it in the sketch, compare with this sketch) passed between 40 Leonis and Gamma Leonis. My plan to watch Vesta over the week as it approach the pair of stars was stymied by cloud and the occasional need to sleep.Fortunately, the sky was clear on the 16th, unfortunately it was also fairly warm, making for horrid seeing conditions. This wasn't much of a problem for binocular sketching, but I also planned to follow Vesta in Don the 8" Newtonian reflector and my ToUCam WebCam.
The field of view of the webcam is pretty restricted, but I calculated that Vesta and 40 Leonis would fit in.
Surprisingly, after a brief interlude where I got the scope on completely the wrong stars, getting Vesta recorded with My ToUCam pro wasn't much of a problem. I did have to crank the shutter speed all the way down and the brightness all the way up (hence the background is blue in this overlay image).I was able to image for about an hour (between Vesta being high enough to clear the trees and having to go to sleep from exhaustion). The movement of Vesta is clearly seen in the overlay image, and here is an animated gif file of Vesta's movement.
Labels: animation, asteroids, astrophotography, Vesta
Thursday, February 11, 2010
Opposition of Vesta February 2010
The North-east horizon as seen in Australia at 11 pm local daylight saving time (10:00 pm non-daylight saving time) showing the location of Vesta (click to embiggen) on the 10th of February.While Mars is the focus at the moment, another opposition is upon us. That of the asteroid Vesta. Remember, an opposition is any time we are directly between an astronomical object and the Earth. Oppositions of Mars and Jupiter can be spectacular, but even humble chunks of rock can have oppositions. We generally don’t notice them, because they are invisible to the unaided eye.
One asteroid is an exception. At certain times the asteroid Vesta (hardly a humble chunk of rock, but the 4th largest asteroid) is visible to the unaided eye. Okay, so its magnitude 6, at the threshold of the eyes ability to see, and even in a strong amateur telescope, Vesta is a featureless dot. But still you are able to see a real asteroid, that was once counted as a planet, a left-over from the era of the formation of the Solar system.
This year, Vesta is not only visible (just, and then only if you are out at dark sky sites away from city lights), but it is relatively easy to find, being within a binocular field of the bright star Algieba (gamma Leonis) in the constellation of Leo. Algieba is the second brightest star in the distinctive, hook-shaped “sickle” of Leo which stars from the bright star Regulus. If you look to the north-east at around 11 pm local daylight saving time the sickle of Leo is clearly visible above the horizon to the right of distinctive red Mars (see Map above). Follow the sickle down from Regulus and you will find Algieba easily. Vesta will be off to the left of Algieba until the 16th, then it will be on the right. Vesta starts off on the 10th one and a half fingerwidths from Algieba, and gets closer every night until the 16th, when Vesta shoots between Algieba and the nearby 40 Leonis. There is only one other star as bright as Vesta within 2 fingerwidths radius of Algieba, and Vesta is obvious as it’s the one that moves from night to night.
Binocular Map showing the location of Vesta from 10-26 February, as seen through 10x50 binoculars (circle indicates field of view, click to embiggen) a printable PDF map is here.Vesta will be at its brightest (and visible to the unaided eye) from 16-22 February, although it will be closest on 22 February (although it will take light 12 minutes to reach you from Vesta). While the challenge is to see Vesta with the unaided eye (again, you will need to be somewhere dark away from city lights to see Vesta without instruments), following Vesta in binoculars is very easy and highly rewarding.
You can test out your sketching skills by sketching the position of Vesta from night to night. The highlight of this opposition will be Vesta passing between Algieba and 40 Leonis on February 16th (update: see my observations here). This is best observed with binoculars or the low power eyepiece of a telescope (otherwise you won’t get both stars and Vesta in the field). Vesta moves fast enough that you can see it drift between the two bright stars.
Labels: 4 Vesta, asteroids, binocular, Observational Astronomy, Opposition, Vesta
Monday, February 08, 2010
Vesta observed (6 and 7 February 2010)
Right: Sketch of Vesta near gamma Leonis on the 6th and 7th of February (Vesta indicated by a "v"), Left; Skymap Pro chart of same area.While Mars is hogging the limelight at the moment, asteroid Vesta is heading for opposition later this month. As Vesta is near Gamma and 40 Leonis, finding it in binoculars is very easy (and Vesta will pass between gamma and 40 Leonis later in the Month too, a very interesting sight).
Since my webcam based imaging system isn't really up to faint stars, I've been sketching through binoculars. My sketches haven't turned out too badly, and the positions of stars and Vesta are pretty good considering I'm just holding my pad (size differences due to my binoculars having a smaller field of view). Some of the stars appear "double", but thats me just trying to darken up the dots, and missing the original in the dark. I can make out stars down to magnitude 9 through the binouclars on a bark night under suburban skies!
Anyone else sketching or imaging Vesta can send me their images if they like and I'll put them up here.
Labels: asteroids, Observational Astronomy, sketch, Vesta
Saturday, May 26, 2007
Where's Vesta?
Where's Vesta? Well, roughly where those yellow lines are just below Scorpius (click to enlarge). I took this image with my Olympus digital camera just before Moonlight overwhelmed Vesta, and you can *just* see Vesta on the 1 Mb original (not on this web version though). If you want to see Vesta with the unaided eye, you have to wait until 5 June, when the Moon rises sunstantially after Vesta.Of course you can see Vesta in binoculars and small telescopes even in the Moonlight, so don't let the Moonlight stop you from looking.
As part of testing the capabilities of "Don", the 8" scope, I took this image of Vesta. It's not very exciting, the magnitude limit of the webcam means that there is nothing else but the bright blob that is Vesta in the field (the streaky bits are hot pixels in the camera). Unfortunately, its not until arround June 17 that Vesta goes near any star that will show up in the webcam.Labels: asteroids, astrophotography, Observational Astronomy, Vesta
Friday, May 04, 2007
A busy celestial weekend
This will be a busy weekend.
Tasmanians will see the Moon will pass in front of the bright star Antares at 5:04 am on Saturday May 5. Antares reappears from behind the dark limb at 5:51 am.
In South Africa the Occulataion is tonight (Friday May 4th). The Moon rises with Antares Occulted, and Antares reappears shortly after Moon rise (7:19pm on May 4th in Capetown). See here for more deatils for South Africa.
Yesterday evening sunspot group 953, which is big enough to see with safe solar projection techniques, blasted out a C9.8 flare. Still don't know if there is a coronal Mass ejection from this one, but if so it could arrive on the morning of the Sunday the 6th of May. Any aurora tocuched off will be weak (Tasmania only), and dimmed greatly by the Moon.
The brightness of the Moon means that the eta Aquariid meteor shower, visible on the morning of Sunday 6, will be almost completely drowned out (charts are here). Similarly, the Asteroid Vesta, which becomes theoretically visible to the unaided eye (under dark skies) on Sunday, will need binoculars to be seen. The morning of Sunday is also the first time comet Encke can be effectively see seen in binoculars (Cahrts for Vesta and Encke are here).
Tasmanians will see the Moon will pass in front of the bright star Antares at 5:04 am on Saturday May 5. Antares reappears from behind the dark limb at 5:51 am.
In South Africa the Occulataion is tonight (Friday May 4th). The Moon rises with Antares Occulted, and Antares reappears shortly after Moon rise (7:19pm on May 4th in Capetown). See here for more deatils for South Africa.
Yesterday evening sunspot group 953, which is big enough to see with safe solar projection techniques, blasted out a C9.8 flare. Still don't know if there is a coronal Mass ejection from this one, but if so it could arrive on the morning of the Sunday the 6th of May. Any aurora tocuched off will be weak (Tasmania only), and dimmed greatly by the Moon.
The brightness of the Moon means that the eta Aquariid meteor shower, visible on the morning of Sunday 6, will be almost completely drowned out (charts are here). Similarly, the Asteroid Vesta, which becomes theoretically visible to the unaided eye (under dark skies) on Sunday, will need binoculars to be seen. The morning of Sunday is also the first time comet Encke can be effectively see seen in binoculars (Cahrts for Vesta and Encke are here).
Labels: asteroids, Astronomy, comets, Occultation, Solar flare, Vesta
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