Left of Mira

[Trevor-Austin]

About 9pm this evening I was looking at Mira and noticed, in a 15mm eyepiece, 8" lx90, about 1/4 fov across to the left (right in eyepiece) an apparent disc about the size and brightness of Uranus. To close to Mira for my 497 to identify, any ideas?

[brantuk]

Wouldn't be Uranus because that's over by Saturn right now. Might have been M77 (galaxy)

[Doc]

Wouldn't be Uranus because that's over by Saturn right now. Might have been M77 (galaxy)

M77 does not look anything like a disc, but then it is the right vicinty.

What scope do you have?

[Trevor-Austin]

Lx90 8" could be a galaxy, just apparently tiny, nowhere near Uranus or Neptune, seen both of them tonight.

To be honest I should ha e gone for some bigger mags to see if it resolved any better but getting too cold. Thought it might have been Neptune when I saw it but when I lazy used goto to find it it was a long way away.

[Trevor-Austin]

Wondering if it could have been any of the huge asteroids out there, have seen a couple before in my previous lx? Tempted to go out again later or def tomorrow if it's clear again.

[Doc]

It's just I've seen M77 a few times in my 16" and if you do see the core it looks elongated and doesn't resolve like a planet, you can tell it's a core.

[Trevor-Austin]

I didn't magnify enough to be sure but it did look circular, not noticed it before when looking at Mira.

[brianb]

With this sort of thing always try slewing the scope a bit. Modern eyepieces are prone to "ghost images" which will appear as faint out-of-focus discs when a bright star is in or near the field of view ... if, when you slew, it moves in the opposite direction to the background stars, it's an internal reflection of some sort. If it remains in the smae position relative to the background stars (but moves in the eyepiece view with them) it's probably a real object.

There is no chance of resolving any asteroid as a disc with a normal amateur scope. They're all well under an arc second in diameter - much smaller than Neptune, or Jupiter's "big four" satellites.

[Talitha]

I simulated your eyepiece view in SkyTools3 (using my 8" LX-10 as the scope), and the only thing that shows up is magnitude 9.4 star HD 14411. Before running the simulation, i made sure to update current objects like asteroids and comets. Hope this helps.

[Trevor-Austin]

It def wasn't a ghost image, not something I've ever seen in this scope, have on others in the past but not on the lx. Have seen light reflections but always obvious. However it could have been a low mag star, can't say I spent too much time being overly careful:) it was approaching -10 last night.

Slightly disappointing but about what I expected, lol.

Slight change of subject then. I get what you say about resolving asteroids but I clearly remember, about 4-5 years ago looking for, I think, Ceres and managing under stupidly high mag getting a grey "blob" on several attempts.

Are you saying that was wishful thinking and completely impossible?

Not challenging or disagreeing, genuinely interested?

[brianb]

OK, here's an alternative explanation ... a satellite orbital change manouevre would result in a small nebula like object which could be of any brightness depending on the distance and the amount of fuel burned. You might have seen a satellite on its way to a geostationary orbit correcting its trajectory. If I'm right, and you'd kept watching the thing, it would have been moving with respect to the stars - possibly pretty slowly though i.e. you would need to watch for maybe several minutes to see any movement - and growing but fading as the exhaust material (which is what you're seeing) disperses into space.

looking for, I think, Ceres and managing under stupidly high mag getting a grey "blob" on several attempts.

If it was Ceres you were looking at - the grey "blob" would be identical to the "blob" of a star at the same magnification.

Look at the Hubble images of asteroids - Ceres is barely resolved - that's with ninety odd inches of aperture and no atmosphere to muck things up. If you're a world class imager (in the Damian Peach bracket), have perfect seeing and a very good scope in the 14"+ bracket, you might just be able to show that an asteroid has a disc different to a star. Visually, with 8", sorry but it's wishful thinking.

[Trevor-Austin]

Damn, as I'm none of those things and don't have the equipment I have been deluding myself:(

That satellite explanation does sound possible, I'll have another look tonight, weather and virus permitting and see if it's gone, which I guess it might well be.

Perhaps it was a death star:)