Five Asteroids Captured in One Field of View with Very Small Telescope

[russw]

I’m continuing to use my little Orion ST-80 to image main belt asteroids. And, I’m continuing to be amazed at how deep this scope can reach from my suburban-urban Bortle 7 backyard in Edmond. Here are some quick-and-dirty blink animations from last night.

I knew asteroids (1277) Dolores and (4259) McCoy were going to be in the field of view, but given their magnitudes, didn’t expect them to be visible. I was wrong. The little ST-80 picked them up at V mags 16.0 and 16.8. Surprise! If I had known they would be detected, I would have framed the image differently.

Anyhow, with these two faint objects, this turned out to be a pretty rich haul for one field. Five asteroids in total.

These images are pretty close to how they were live-stacked at the telescope. Just some curves and gaussian blur applied post. As you can tell from the bouncy stars, the two images used for this blink-animation were hand-registered.

Animation covers one-hour. Each image is a stack of 6 at 60 seconds.

I will try to update this post with more polished animations soon.

Click here for a larger image.

Scope: Orion ST-80 (80 mm f/5)
Camera: ZWO ASI482MC

Note (12-18-23): Image captions corrected to show the correct spelling for “Dolores.”

[mpsurge]

Wow, was this planned or a happy accident?

[russw]

Joel,

Happy accidents don’t come my way very often. I had to plan this one, at least for the three brightest asteroids.

I didn’t think McCoy and Dolores would be detectable so I centered mainly on Emita, Padua, and Cornelia. I left a little room near the edge for McCoy and Dolores, just on the off chance one or the other might be bright enough to show up.

I planned the shot with Stellarium using the coordinates of the center reticule as the point I slewed the telescope to.

Here’s a screenshot of Stellarium showing how I planned the image.

P.S. It looks like I misspelled “Dolores” on the image captions. I’ll fix that in the final versions.

P.P.S. I couldn’t stand it. Image captions fixed.

[mmabbott]

That is really good work. To know what you are looking for and to find it. In town too.

[mpsurge]

Lol, well congrats on a well planned image!

[Mitche]

A remarkable image Russ! And a great example of how pre-planning can help get amazing images!

[russw]

I previously posted about capturing five asteroids in one field of view, and included a quickly-done blink animation. I have since completed a full animation covering just over an hour’s worth of asteroid movements. Unfortunately, I have had to reduce the number of asteroids captured from five to four.

While processing the images for the animation, it became apparent that the object I previously identified as asteroid (4259) McCoy was not actually an asteroid. The object was very close to where it should have been in the sky. But, it was likely either a hot pixel or internal reflection.

While the object showed continuous movement during full animation, it was moving in exactly the opposite direction that (4259) McCoy should have been moving. Additionally, while (4259) was predicted to be at V magnitude 16.8, the object in the images was clearly brighter than asteroid (1277) Dolores, which was at V magnitude 16.0.

I removed the hot pixel/reflection in processing the images for this animation, leaving just four asteroids in the field. Even with magnitude 16.8 (4259) McCoy out of the picture, I’m still pleasantly surprised that this little 80 mm telescope and ZWO ASI482MC camera can get down to magnitude 16.0 with one- minute subs.

The final animation follows, with a cropped and enlarged section on the area around 16th magnitude (1277) Dolores following it. Full details follow the animations.

See a larger version of this animation here.
(Right click to open in a new window)

Observation Details
December 18, 2023 04:53:41-05:59:27 UT
Seeing: Fair Transparency: Good Sky Condition: Bortle 7
Location: Edmond, Oklahoma USA

Image Details
66-minute time-lapse animation.
North is up. East is Left.
12 images, each a stack of 6 @ 60 seconds (total integration per image 360 seconds/ 6 minutes).
Gain 250
FOV:
481, 363, 425, 1277: 78.8’ x 49.3’ (1.3°x 0.82°)
1277: 14.8’ x 9.87’ (0.25° x 0.16°).

Equipment
Telescope: Orion ST-80 (80 mm f/5) + Orion Field Flattener + Baader Fringe Killer Filter
Camera: ZWO ASI482MC
Guide Scope: SVBONY SV165 (30 mm f/4)
Mount: Celestron CGEM

Image Capture & Processing
Capture: SharpCap Pro
Guiding: PHD2
Process: Deep Sky Stacker, GIMP

[Mitche]

Very nice, Russ! Too bad about the 5th asteroid, but it’s a great image with “just” 4!