8 replies to this topic

[jiawen]

A couple nights ago, I got a pretty nice few hours on the Leo Triplet (M65, M66, and NGC3628). Right smack between them is a streak. I'm almost certain it's not a satellite, because it moves only a tiny bit over the course of the night, and I've checked SkySafari for satellites in that area. Also, the streak goes away during periods when I was doing the meridian flip, changing the battery, etc. I've checked the subs, and it definitely moves from sub to sub. So I'm pretty certain it's an asteroid/minor planet.

 

I checked the DE430 asteroids catalog in Pixinsight's AnnotateImage script, but it's not revealing anything there. I've tried a few other built-in PI catalogs and none of them have revealed what the object is. Are there other ready-made catalogs for PI that will identify what object this is? Barring ready-made PI catalogs, what's a good, medium-sized Vizier catalog that would do the trick?

[james7ca]

SkySafari Pro shows the asteroid (888) Parysatis passing between M65 and M66 on January 12, 13, and 14 and then passing by NGC3628 on Jan 18. It's moving fairly slowly, looks like if I had centered on the Leo Triplet it would have entered the field of my SV80 with an ASI183 camera on January 10.

 

According to SkySafari Parysatis is a 13th magnitude, main belt asteroid that is 44km is size.

Edited by james7ca, 17 January 2021 - 10:02 AM.

[jiawen]

Huh, thanks for finding that! But I just updated my SkySafari (4, Pro)'s minor planet data, and though it shows (888) Parysatis in that region at that time, it's way closer to n Leonis than to M65. My SkySafari shows it as being about 1.5° away from where the streak actually is. In my subs, the streak really is smack in the middle of the three galaxies -- very close to equidistant. SkySafari shows (888) Parysatis moving on about the same vector as the streak in my image, though. Could SkySafari be that far off?

[james7ca]

I don't no, below is how it appears in my copy of SkySafari Pro on an iPad (v6). However, did you quit and relaunch SkySafari after updating the database? Also, sometimes the update takes a long time to download and install.

Attached Thumbnails

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[RedLionNJ]

I believe James to be right. Here's the same area from Guide 9.1,  20:20UT,  Jan 15:

 

 

Guide uses MPCORB, so it's as accurate as any planetarium-style app.

[jiawen]

Excellent! Thank you both for the confirmations. I checked the JPL and ESA minor planet ephemerides to confirm, and sure enough, it's 888 Parysatis! Nifty.

 

I wonder why my SkySafari's positioning is so far off? Hmm. Well, a problem for future me, I guess.

[james7ca]

Excellent! Thank you both for the confirmations. I checked the JPL and ESA minor planet ephemerides to confirm, and sure enough, it's 888 Parysatis! Nifty.

 

I wonder why my SkySafari's positioning is so far off? Hmm. Well, a problem for future me, I guess.

Did you recheck SkySafari as I mentioned above? Sometimes the database download and update takes a very long time (you may even have to try to download the update again, then wait for ten minutes and/or restart the app.

[RazvanUnderStars]

I checked the field out of curiosity and in fact there are a few other asteroids there (Koppel, Gerbefremov and Masakatsu). They are fainter, but you may notice them. I'm attaching a screenshot from the SkyTools atlas and then the trails of those asteroids (the asteroid names disappeared when I enabled the trails, perhaps a bug so that's why I'm including the first one as well).

 

 

 

 

 

[jiawen]

Did you recheck SkySafari as I mentioned above? Sometimes the database download and update takes a very long time (you may even have to try to download the update again, then wait for ten minutes and/or restart the app.

Yep, I started updating the minor planet data, let it run & finish (it was actually pretty quick), then restarted the app. Now I've done it twice, just to make sure. SkySafari still shows 888 as quite close to n Leonis -- far closer to that than to M65 (which is the nearest of the Trio). No idea what's up with my app. Oh well!

 

I checked the field out of curiosity and in fact there are a few other asteroids there (Koppel, Gerbefremov and Masakatsu). They are fainter, but you may notice them. I'm attaching a screenshot from the SkyTools atlas and then the trails of those asteroids (the asteroid names disappeared when I enabled the trails, perhaps a bug so that's why I'm including the first one as well).

Thank you for checking that! I downloaded an orbital path map from AstDyS-2, and then overlaid it with my in-process astrophoto. The track aligns almost perfectly with 888. Thank you for the additional confirmation, though!