PDA

View Full Version : Thebe and Amateur Astronomers



Eroica
2005-Aug-29, 01:54 PM
Is Jupiter's moon Thebe (http://www.ifa.hawaii.edu/~sheppard/satellites/jupsatdata.html) within reach of amateur scopes?

Its magnitude is about 16 and it orbits closer than Io. Its maximum separation from Jupiter is about 73''.

Donnie B.
2005-Aug-29, 02:03 PM
Considering that the BA's "new" scope is a 12.5" and he's hoping to see stars down to just magnitude 13, I doubt that any amateur instrument could get to 16.

ngc3314
2005-Aug-29, 02:19 PM
Considering that the BA's "new" scope is a 12.5" and he's hoping to see stars down to just magnitude 13, I doubt that any amateur instrument could get to 16.

Ah, you reckon without the seriousness of some amateur astronomers! There are people with 20-36" instruments who will go out to look for the double quasar (magnitudes 17 or so) and the jet of M87 (magnitude 15 but buried in a big galaxy). The problem with Thebe, as with the Martian moons which I've never seen either, is that it lies deep within the glare of scattered light from the planet. However, it could be an interesting target to get on an image, where you can stack and process images; enough exposure time can make up for these problems for some kinds of target.

(And the now-BA 12-inch would probably go closer to 14 from a good dark site; I've sen Pluto with a 10-inch, which is nowhere near an aperture record).

die Nullte
2005-Aug-29, 02:40 PM
Considering that the BA's "new" scope is a 12.5" and he's hoping to see stars down to just magnitude 13, I doubt that any amateur instrument could get to 16.

In visual observation, my 12.5-inch f/5 Newtionian has pulled in mag 15.6 stars. Mag 13 should be easy, even with an 8-inch. Mag 16 stars might be possible in the 12.5 with younger, better eyes than mine.

Eroica
2005-Aug-29, 02:51 PM
However, it could be an interesting target to get on an image, where you can stack and process images; enough exposure time can make up for these problems for some kinds of target.
That was one possible way I thought of that dedicated amateurs could use to "collect" Thebe. CCDs and sophisticated software have made it possible to "image" many things that cannot be seen live at the eyepiece.

Still, I'm thinking that even live, Thebe might just be within reach of a well-heeled amateur.

Glom
2005-Aug-30, 11:56 AM
If you set up a few telescopes, maybe you could build your own interferometer.

die Nullte
2005-Aug-30, 02:01 PM
If you set up a few telescopes, maybe you could build your own interferometer.

I few years ago Sky & Telescope had an article about someone who made an interferometer by putting a mask with two slits on the front of a C8.
-----------
Edited on Sep 5 2005 to fix funny conversion of ampersand during forum migration.

George
2005-Aug-30, 04:54 PM
Would "Jupitershine" improve magnitude a noticeable amount (maybe 1/2 mag.)? [Of course, orbital position would be critical for this.]

AstroRockHunter
2005-Aug-30, 07:54 PM
Magnitude wise, it would be possible to see Thebe with an amateur telescope. However, with only 73 arcsec seperation, then you would need a large apeture telescope to resolve it.