imaging a small asteroid

[bomberbaz]

Hello all, don't know if this is feasible so I thought I better ask before devoting a lot of effort.

There is an asteroid called "(3922) Heather" in Virgo at a magnitude of 19.3 and given size 20km dia at 3.1 au. Is this doable for imaging? RA 11h 57m 00.76s by dec +00 35' 26.1" as at time of post.

It dioesn't show in stellarium but is in sky safari.

I have no intention of trying myself, it is beyond my own capabilities but I could either use a remote telescope and pay or employ the services of someone on here.

It is for sentimental purposes, something I thought about a few years back but now is the time I see if my thoughts were reality!

Any help or tips gratefully received.

Steve

[ONIKKINEN]

The target will be about a milliarcsecond in apparent diameter, so will appear like any other dim star. But from a magnitude point of view i dont see why not, just need to spend some time on it. Plenty of magnitude 19 stars can be seen in an image with some time spent on it, and i think my magnitude record is somewhere in the 22 ballpark, but that took over 30 hours from good skies so probably not what you're looking for.

If you tried this, you should take as long an exposure as you possibly can and stack without rejection (so that the rejection algorithms dont discard it if/when it moves between subs a little bit but not sure how quickly it would move at this distance).

[bomberbaz]

19 hours ago, ONIKKINEN said:

The target will be about a milliarcsecond in apparent diameter, so will appear like any other dim star. But from a magnitude point of view i dont see why not, just need to spend some time on it. Plenty of magnitude 19 stars can be seen in an image with some time spent on it, and i think my magnitude record is somewhere in the 22 ballpark, but that took over 30 hours from good skies so probably not what you're looking for.

If you tried this, you should take as long an exposure as you possibly can and stack without rejection (so that the rejection algorithms dont discard it if/when it moves between subs a little bit but not sure how quickly it would move at this distance).

Thanks for the information, this is helpful.

The insightobs have a 12.5" RC scope available from chile so I am hoping they will be able to get this without spending a fortune on obs time and just running a test on drift time before I book a slot. I am hoping from there it will gather enough in less than an hour thus avoiding costs but more importantly, drift.

[Cosmic Geoff]

You should figure out how fast it is moving.  If it doesn't trail on a stacked image you will need to image it twice a suitable time apart. There will be a lot of stars in the image at around mag. 19 and you have to figure out which dot is 3922.

[bomberbaz]

12 hours ago, Cosmic Geoff said:

You should figure out how fast it is moving.  If it doesn't trail on a stacked image you will need to image it twice a suitable time apart. There will be a lot of stars in the image at around mag. 19 and you have to figure out which dot is 3922.

Yes never thought about identifying it amongst a see other other stars.  Well over 13 hours RA is stable where as dec it is moving at around 0.65 seconds an hour.  Not sure how this computes into imaging without trailing maximum time?

[Xilman]

On 14/01/2024 at 00:44, bomberbaz said:

Hello all, don't know if this is feasible so I thought I better ask before devoting a lot of effort.

There is an asteroid called "(3922) Heather" in Virgo at a magnitude of 19.3 and given size 20km dia at 3.1 au. Is this doable for imaging? RA 11h 57m 00.76s by dec +00 35' 26.1" as at time of post.

It dioesn't show in stellarium but is in sky safari.

I have no intention of trying myself, it is beyond my own capabilities but I could either use a remote telescope and pay or employ the services of someone on here.

It is for sentimental purposes, something I thought about a few years back but now is the time I see if my thoughts were reality!

Any help or tips gratefully received.

Steve

Should be straightforward with a decent camera and an aperture of at least 20cm. I have imaged satellites in the outer solar system such as Siarnaq (http://www.astropalma.com/Projects/Satellites/siarnaq.html) and Caliban (http://www.astropalma.com/Projects/Satellites/caliban.html) at magnitude 21 or fainter.

You will almost certainly need to take many subs and stack on the predicted motion of the asteroid as it will be too faint to show up on exposures long enough for it not to be trailed.

I am almost tempted to image it myself but that would spoil your fun.  Virgo is a bit late in the night right now, for that matter.

 

[Xilman]

On 15/01/2024 at 10:08, bomberbaz said:

Yes never thought about identifying it amongst a see other other stars.  Well over 13 hours RA is stable where as dec it is moving at around 0.65 seconds an hour.  Not sure how this computes into imaging without trailing maximum time?

Turns out to be remarkably easy for something that bright, unless the field is very crowded..  Head over to https://aladin.cds.unistra.fr/AladinLite/ and type in the co-ordinates of the target. Zoom in to a field less than a degree across. In the default DSS2 image stars down to about g=21 will be shown. Switch on the Gaia DR3 display and you can find the magnitudes of the stars in the field. If you then image and stack as you go until you can see stars at least as bright as your target you will be able to identify it in the final stack because you can then do heavy duty contrast stretching.

Actually, I do that before starting imaging. No use even starting if the predicted position is too close to a star as bright or brighter.

 

[bomberbaz]

On 03/02/2024 at 12:55, Xilman said:

Turns out to be remarkably easy for something that bright, unless the field is very crowded..  Head over to https://aladin.cds.unistra.fr/AladinLite/ and type in the co-ordinates of the target. Zoom in to a field less than a degree across. In the default DSS2 image stars down to about g=21 will be shown. Switch on the Gaia DR3 display and you can find the magnitudes of the stars in the field. If you then image and stack as you go until you can see stars at least as bright as your target you will be able to identify it in the final stack because you can then do heavy duty contrast stretching.

Actually, I do that before starting imaging. No use even starting if the predicted position is too close to a star as bright or brighter.

 

finally found it amongst the other stars, thanks for the link, that really helped.

I plotted a line of the asteroids course over 3 nights and then used this to compare to the maps in the link you provided. 

cheers

steve

[Xilman]

1 hour ago, bomberbaz said:

finally found it amongst the other stars, thanks for the link, that really helped.

I plotted a line of the asteroids course over 3 nights and then used this to compare to the maps in the link you provided.

Well done!

I've not had chance to have another go since the images I sent you.  Poor weather and social occasions.

Paul

[AKB]

On 14/01/2024 at 00:44, bomberbaz said:

It dioesn't show in stellarium

Turns out that this is easily added in Stellarium using the Solar System editor and importing it from the MPCAT list of numbered objects.

[bomberbaz]

2 hours ago, AKB said:

Turns out that this is easily added in Stellarium using the Solar System editor and importing it from the MPCAT list of numbered objects.

I added in stellarium already, used that to track it across my image, just not enough stars to figure with which to make a decent comparison to my image.

The other problem I have is the observatory haven't provided exact time the image was taken so I needed to run a detailed comparison with a starmap and the DSS2 map on this Aladin Lite (unistra.fr) provided it.  Hard work but worth the effort.