[X] My Assistant

[elakdawalla]

Hi everybody,

I was talking with Amanda Hendrix at JPL today about the upcoming icy satellite encounters, and she asked me if I had any way of getting in touch with amateur observers. They are looking for people to do photometric observations of Hyperion for several days on either side of the flyby. She said: "Ground-based observing will help to constrain the current state of rotation of Hyperion, whose spin axis changes. The visual magnitude of Hyperion is 16.5, so serious photometry would require at least a 24-inch telescope."

Gulp. That's a big telescope, and short notice, with the encounter only 6 days away. I'm not an observer so I don't know how to get in touch with lots of amateurs with big scopes except for the couple of people I know personally. Can anybody on this board help get the word out?

--Emily

[elakdawalla]

It turns out there's hope for people with smaller telescopes after all. I got this in an email from Anne Verbiscer yesterday (she's the U. of Virginia planetary astronomer who did those Earth based opposition effect studies of Saturn during Earth's central transit across the Sun as seen from Saturn in January):

I took a look at your online entry calling for observations of Hyperion and found that you might be discouraging some potential observers by saying that they need to have a telescope 24-inches or larger.  One may need a substantial telescope in order to see Hyperion through an eyepiece with your own eye, but a CCD on even a modest (~ 8") telescope can make a long exposure and observe Hyperion quite easily.

Also, not to nitpick about numbers, but a quick check (i.e. Google) on the V magnitude of Hyperion comes up 14.2, not 16.5. That is an estimate of its magnitude at opposition (which we are nowhere near... the phase angle now is more than 6 deg.), so it will be dimmer than 14.2, but not by more than 2 magnitudes.

--Emily

[odave]

That's true, but I wondered if the eposure length would impact the data, and if having something bright like Saturn nearby would saturate the camera. I've never tried to image any of the moons by themselves - anyone else?

I may give it a shot, though my camera dates from those ancient days when a 640x480 CCD was considered "good" amateur equipment (1998).