Search found 9 matches

by Ray-Optics
Mon Mar 13, 2017 12:27 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Saturn's Moon Pan from Cassini (2017 Mar 13)
Replies: 44
Views: 6678

Re: APOD: Saturn's Moon Pan from Cassini (2017 Mar 13)

Since Pan orbits in the Encke gap along with an irregular ringlet, a hypothesis for the hat brim occurs to me: It is picking up "snow" from this ringlet along its "equator" of spin. Pan's gravity must be very low, so ring snow could pile high. An overall snow layer may also accou...
by Ray-Optics
Fri Oct 10, 2014 1:43 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Moons at Opposition (2014 Oct 10)
Replies: 13
Views: 45128

Re: APOD: Moons at Opposition (2014 Oct 10)

Notice that Uranus is not circular. It looks to be in gibbous phase, but that cannot be because it's in virtually the same direction as the moon in opposition. No, this is an aberration caused by the optics of the telescope itself, and is of course most prevalent at the edges of the field.
by Ray-Optics
Fri Nov 15, 2013 1:51 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Jets of NGC 1097 (2013 Nov 14)
Replies: 49
Views: 8533

Re: APOD: The Jets of NGC 1097 (2013 Nov 14)

Beyond wrote:I was waiting to see if anyone commented on the one in the 3 o'clock position that seems to make a 90' turn. I thought that was a bit strange. What in space makes right angles?
Exactly my question. I mean, whuh??
That should be the subject of a whole discussion if not a research project.
by Ray-Optics
Mon Dec 31, 2012 1:05 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Saturns Rings from the Dark Side (2012 Dec 31)
Replies: 27
Views: 5468

Re: APOD: Saturns Rings from the Dark Side (2012 Dec 31)

RedFishBlueFish: I wondered about that too. It can't be a crater. It almost looks like an asteroid impact only a few hours old. I'm surprised it wasn't mentioned by the editor.
by Ray-Optics
Mon Dec 31, 2012 1:01 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Saturns Rings from the Dark Side (2012 Dec 31)
Replies: 27
Views: 5468

Re: APOD: Saturns Rings from the Dark Side (2012 Dec 31)

Yes, we see sunlight on Saturn's face. Imagine you're Saturn and you're wearing a broad-brimmed hat. You pull the hat down against the sunlight. Now, are you looking at the dark side of the brim? Yes.
by Ray-Optics
Fri Aug 05, 2011 12:46 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Summer Night's Dream (2011 Aug 05)
Replies: 33
Views: 11452

Re: APOD: A Summer Night's Dream (2011 Aug 05)

Interesting to note that not a single one of the firefly trails is convex upward. They all seem to flash as they're pulling out of a dive. I wonder if anyone has studied the coordination of their flashes with their flight patterns? (As a process engineer I've learned to look for subtle clues, and I ...
by Ray-Optics
Sat Jul 03, 2010 6:02 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Giant Planet for Beta Pic (2010 Jul 03)
Replies: 12
Views: 2649

Re: APOD: A Giant Planet for Beta Pic (2010 Jul 03)

Ann notices that astronomers have concentrated on low-mass stars, but this one has a higher mass. That's because the first exoplanet searches were limited to Doppler shifts of the star, and the smaller the star (and larger and closer the planet) the greater the shift. So the ones showing up first we...
by Ray-Optics
Wed Oct 07, 2009 1:31 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: A Doubled Ringed Basin in Mercury (2009 Oct 7)
Replies: 25
Views: 3981

Re: A Doubled Ringed Basin in Mercury (2009 Oct 7)

It is unlikely that any particular crater would be double-drilled, but considering the number of craters observed and our penchant for finding patterns and symmetry, it is just as unlikely that we wouldn't have found this rare occurrence. The "clue" about the smoother interior region could...
by Ray-Optics
Tue Mar 31, 2009 2:29 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: The Tarantula's Heart (2009 March 31)
Replies: 18
Views: 1930

Tarantula's Heart: Yellow donuts

I'm curious about the yellow "donuts" around the perimeter of this composite. Notice that the reddish stars show diffraction spikes as we'd expect with a narrow-band filter and negligible aberrations. This is true (for at least some) all the way to the edge of the field, so I doubt off-axi...