Jump to content

Banner.jpg.b89429c566825f6ab32bcafbada449c9.jpg

Asteroid 4 Vesta


Sargs

Recommended Posts

Had a bash at some minor planet spotting on Friday night/Saturday morning. Pointed the scope at a fairly nondescript bit of space between Gemini and Cancer and started taking pictures.

The star in the middle of the field is (I believe!) asteroid 4 Vesta at a distance of some 227 million kilometres. I took five frames over a period of twenty-five minutes before the clouds came over to see what I was doing, but even over this short a period, you can see some elongation of Vesta as it drifts relative to the fixed background stars. 

Interesting way to spend some time since the weather wasn't ideal with partial, intermittent cloud. Since I was looking for motion between frames, I didn't mind if I lost half my subs to the weather gods!

Telescope was a William Optics FLT-98 with AFR-IV focal reducer

Camera was a ZWO ASI1600MC-cooled. No flats or darks, as I was just mucking about really. Would have liked to get a couple of hours, but if the weather had been good enough for that, I'd probably have gone nebula-hunting. It was interesting to deliberately go hunting for a specific asteroid; normally, I just find them after the fact, messing up my pics of something else!

Vesta_big.jpeg

Link to comment
Share on other sites

  • Replies 40
  • Created
  • Last Reply

That is just incredible. (Bows down in Wayne's World style not worthy...ness).

 

Shows my beginner status when I thought images like that were way beyond the reach of anyone without a big observatory on a mountain top. Thanks for the eye opener.

Link to comment
Share on other sites

2 minutes ago, Daz69 said:

How the hell do you find a spec that's hardly moving (relatively speaking)?

I look on Stellarium to see where it is then snap around randomly with DSLR on the SW Star Adventurer until I find it :grin:

Dave

Link to comment
Share on other sites

I done a 2 star alignment, already had Vesta's location on Stellarium which I used to send the mount to it and it came straight up on the screen where I expected it to be.  Both shots were taken with the QHY8L on an Evostar 80ED Pro, the mount is a NEQ6 Pro.

JIm

Link to comment
Share on other sites

37 minutes ago, JimT said:

I done a 2 star alignment, already had Vesta's location on Stellarium which I used to send the mount to it and it came straight up on the screen where I expected it to be.  Both shots were taken with the QHY8L on an Evostar 80ED Pro, the mount is a NEQ6 Pro.

JIm

GoTo ? that's cheating :grin:

Dave

Link to comment
Share on other sites

Purely for fun, I aligned three of the images above - taken, I believe, on three consecutive nights.

vesta.jpg

 

 

Using Astrometry.net on two of the originals (minus annotations), I determined field of view and pixel scale, such that I could estimate the apparent movement of Vesta to be ~0.25 degrees/day.

If Vesta orbited Earth and assuming a circular orbit, then one could incorrectly estimate an orbital period of 1440 days (actual 1325 days). It's not circular, though, nor does it orbit Earth.

If Vesta were stationary, then given that we've travelled approximately 5 million km in the last two days and that Vesta is just past opposition (last week), then parallax and simple trigonometry can be used to estimate its current distance from Earth as approximately 1.97 AU (Stellarium gives ~1.5 AU). But it's not stationary, so both parallax and relative motion come into play.

 

I have no idea how to resolve these, or whether it's even possible without further data. Regardless, thanks for posting these images - hope this is of interest to some, albeit wrong.

Matt.

Link to comment
Share on other sites

1 hour ago, JimT said:

I done a 2 star alignment, already had Vesta's location on Stellarium which I used to send the mount to it and it came straight up on the screen where I expected it to be.  Both shots were taken with the QHY8L on an Evostar 80ED Pro, the mount is a NEQ6 Pro.

JIm

I did much the same but I used plate solving to get the initial alignment. When it works, it's the best thing ever. When it works...

Link to comment
Share on other sites

I did a plate solve on the first photo but it did not tell me anything I knew already so I stuck to Stellarium and what I could see on the monitor, and just went for the second night shoot.  As soon as I seen the monitor I knew I had it and took the photo.

Jim

Link to comment
Share on other sites

I was just using the Star Adventurer and DSLR, could have plugged into laptop and plate solved it but it's more fun searching for it.

Quite a decent FOV using 300mm lens so only takes a few minutes.

When it was near M44  in December it was really easy to find.

Dave

Vesta.gif

 

 

Link to comment
Share on other sites

Well as every man and his wife go after the nice colourful nebuli I like to chase comets as well, this was my first foray into asteroids, something nice about being spot on with the equipment :)

Jim

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.