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I wanted to observe some asteroids as I had not done it for a while, and the easiest way to spot and identify them seemed to be to use my EEVA rig.  Identifying an asteroid visually can be difficult unless one is sure to look in the right place and has a star chart that matches the eyepiece field size and the magnitudes of the visible objects. And the image reversal in a star diagonal makes it much more difficult.

On 18 Feb I imaged four asteroids using: 102mm f5 achro, ASI224MC camera and SLT GoTo mount.  Vesta, Melpomene, Echo and Amphitrite.  I plate-solved the images the next day, to find that I had got Melpomene and Echo but missed the other two.

On 22 Feb I imaged Vesta, Amphritite, Eunomia and Irene, using live-stacking, with 102mm f5 achro, ASI224MC camera and EQ5 Synacan GoTo mount.  I plate-solved the images at the telescope, to find that I had three of them but needed to change the aim and repeat to get Irene.   With this setup, a mag 9 to mag 10 asteroid shows up clearly on the laptop screen as a bright dot with a 5 second exposure.

Platesolver 2 highlights any non-catalog items in the field and one can check the co-ordinates of any object in the solved field. The image reversal in a star diagonal does not trouble it at all.

I have had the EQ5 Synscan upgrade for around 10 months but this is the first time I have managed to do anything really useful with it.

It would be interesting to observe asteroid movement over a period of time but with the current rotten weather it is good to have a method that only requires one image or stack to positively identify the asteroid.

One of the images appeared to have two bright non-catalog objects on it, which is something I may investigate later.

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I like asteroids but with one thing or another I've not got round to capturing many.

A week or so ago I did make an effort with Hygiea. I confirmed it visually by it's position in the field stars but my plan to make a gif showing movement was thwarted no end of issues. 

A program I use a lot is ASTAP and it will plate solve then annotate DSO and/or Comets and Asteroids. You just have to download a couple of files from the Minor Planet Center. Here is what is what it does:


Ignore the trailing; mount problems! But it's got Hygiea spot on! There are about 10 other asteroids in that field but all greater than mag 18 and not visible in this 30 sec sub. I've got the annotation tool set for max mag of 16.

Results are better if a full FITS header is available it saves entering image details and makes solving almost instantaneous.

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26/02/21. With the moon blazing away I thought I would try my hand at finding some bright asteroids. 

I used the 15"Dob/ultrastar camera. The moonlight is a pain but these asteroids at around mag 12 are easily picked up, even in a 2 second sub.

Psyche: a 200 km wide nickel-iron main belt asteroid. Take a look at https://3d-asteroids.space/asteroids/16-Psyche



Asteroid Nemausa - 140 km diameter. Take a look at https://3d-asteroids.space/asteroids/51-Nemausa for its likely shape. Made up of nickel, iron, cobalt, water, nitrogen and ammonia.



Asteroid Eurynome -  diameter 64 km. Take a look at  https://3d-asteroids.space/asteroids/79-Eurynome  for 3D model . A siicate asteroid




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27/02/21 - I  tracked down a few more asteroids last night for an hour.

Asteroid Daphne - I offset the view so has to pick up NGC 2186 (bottom left). Daphne is about 200 km across and is made of  nickel, iron, cobalt, water, nitrogen, ammonia.


























Asteroid Nephthy -about 60 km across, The blue lines point to mag 17 LEDA galaxies.



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Nephthys -- what a great field, Mike. There seems to be a whole load of faint galaxies to the north too. Lovely round stars too!

This asteroid hunting sounds like a fun idea Geoff.

I took a look at the data from the MPC, all 650M of it. It would be interesting to incorporate it into the platesolving routine at some point.


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28/02/21 - Approx 24 hrs since I looked at Nephthys. The shot below shows how far it has travelled in those 24 hrs. Last night's position is marked by the red dot. I have also marked on the 3 LEDA galaxies from last night and also the other 2 LEDA galaxies that Martin indicated.  Conditions were better tonight as the moon was still below the horizon, hence a darker background.



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