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Posted by: wildespace Apr 14 2017, 02:47 PM

Are there any Cassini images of the moon Aegir? (There's got to be, to make its discovery possible)

http://en.wikipedia.org/wiki/Aegir_(moon)

Nothing come up from the search at the raw images archive. I hadn't had a look at the PDS archive yet. Any help would be welcome.

The issue is, some online sources use an image of Hyperion to illustrate Aegir.

So, to restore justice, as it were, I'd like to see some images of Aegir itself.

Posted by: stevesliva Apr 14 2017, 03:09 PM

It's going to be pixels and phase curves. When you look at the list of the moons of Saturn at the bottom of that Wikipedia article, it's not like any of the Inuit, Gallic, and Norse groups have any features to see in images, with the notable exception of Phoebe.

Posted by: Paolo Apr 14 2017, 04:01 PM

the moonlet was discovered by Earth-based telescopes, like most of the irregular sats.
I don't know if Cassini ever oberved it. even if it did, expect it to be a handful of pixels at best

Posted by: Phil Stooke Apr 14 2017, 06:26 PM

The list of tagets on this site:

https://saturn.jpl.nasa.gov/galleries/raw-images/

does not include Aegir, so it looks like there are no targeted images of it. For many other small outer moons they did take repeated images for light curves, phase functions and so on, but not Aegir apparently.

Phil

Posted by: Themisto Jan 1 2019, 02:49 PM

Aegir was never targeted by Cassini. I considered it for June 2015, but due to the uncertain ephemeris and competition with other targets, this did not happen.

From the 38 irregular moons of Saturn known to date, 25 were successfully observed:
Phoebe
All Inuits: Kiviuq, Ijiraq, Paaliaq, Siarnaq, Tarqeq.
All Gallic: Albiorix, Bebhionn, Erriapus, Tarvos.
15 Nordic: Bergelmir, Bestla, Fornjot, Greip, Hati, Hyrrokkin, Kari, Loge, Mundilfari, Narvi, Skathi, Skoll, Suttungr, Thrymr, Ymir.

Attempted, but not successful due to mis-pointing were observations of Surtur, Jarnsaxa, and S/2004_S12.

~~ Tilmann

PS: I started to compile all available information of Cassini observations of irregular moons on my website, including individual sites for each moon. By coincidence, the Aegir page is already near completion. It can be found here: https://tilmanndenk.de/outersaturnianmoons/aegir/

Posted by: machi Jan 10 2019, 12:48 PM

Wow, that's a fantastic source for info about irregular satellites! Thank you!