Starship Asterisk*

Upon further investigation back here on Earth, I think I might have only just captured a suggestion of the Encke Minima (the slightly darker mid-portion of the A Ring), and not the Encke Gap (a small but actual gap just inside the outer edge of the A Ring). It could even be a mere artefact of the over-sharpening. It is good when an artefact looks like an illusion of something real.

I'd say you've imaged the Encke gap. I mean, it's not like you are ever going to get a black pixel right where the gap is but there is a slightly darker line there and the Encke gap is the cause.

geckzilla wrote:I'd say you've imaged the Encke gap. I mean, it's not like you are ever going to get a black pixel right where the gap is but there is a slightly darker line there and the Encke gap is the cause.

I want to think you're right, but I'm not so sure anymore. It seems just as likely to be some kind of "resonance" falling out of the wavelet sharpening. I don't really know much about wavelet sharpening (yet), but I remember studying Fourier analysis up to a point, and there would appear to be enough similarities to raise my suspicion.

Here is the original unsharpened image, produced from almost 500 stacked and aligned video frames in Registax 5: I'd be interested in anyone's opinion, who can be bothered to mess around with my meagre offerings.

Pretending like this is the best picture of Saturn I have ever seen and I am unaware of the Encke gap then yeah, I probably wouldn't think there is a gap there at all. Your data are garbled by the JPEG compression, though. Someone clever might be able to infer that there is a probability of a gap or darker colored ring section being at that position, though.

Oops. I've replaced my jpg with a cropped tif.

I stared and stared and can't say for sure. I'd lean toward no after looking at the TIFF though.

I'm going with Encke Minima, or an artefact that happens to look like it. Ahem, moving on ...

1 hour, 20 minutes worth of New York City star trails. These ones are coming in for a landing at LaGuardia airport to the northwest of my second-story observatory. I crafted a street light occulting disk out of a few handy objects. I do not go outside because going alone as a smallish female with non-trivial camera equipment is honestly scary. I don't think anyone would rob or hurt me, but the prospect seems much more likely than, say, being attacked by a bear in a forest at night.

Cool! Love the occulting disc. But I'm surprised you didn't consider pulling out your handgun to shoot the light dead. Probably keeps the muggers and bears (oh my) at bay, too.

I maliciously dream of dismantling or destroying that street lamp on a regular basis. My dream is that one day a drunk driver plows into it with a car.

geckzilla wrote:I maliciously dream of dismantling or destroying that street lamp on a regular basis. My dream is that one day a drunk driver plows into it with a car.

In most places the power company or city utilities will install a partial shield on streetlights that shine into windows. Have you asked?

I wouldn't know who to ask.

geckzilla wrote:I wouldn't know who to ask. :o_O:

I expect you're resourceful enough to figure it out. (Like calling the city and asking who to talk to about a broken streetlight.)

Yeah, you would expect that, I mean it's just a telephone. I would never get sweaty palms or anxiety over a telephone call.

A pretty full Moon coming up a couple of nights ago, just visible between the top of the mountain and the bottom of a low cloud layer.

I saw Antares this (very) early morning! Not bad! Here in Scandinavia we can only see Scorpius (the northernmost part of it) in the summer, but in the summer our skies are so light that it's hard to see many night sky objects at all. Here in southernmost Sweden it does get dark, even around midsummer, but we don't get that many hours of darkness.

Well, we get the darkness back, with a vengeance, in November, December, January, February... groan... I don't want to think about that in May!

Ann

Ann wrote:I saw Antares this (very) early morning! Not bad! Here in Scandinavia we can only see Scorpius (the northernmost part of it) in the summer, but in the summer our skies are so light that it's hard to see many night sky objects at all. Here in southernmost Sweden it does get dark, even around midsummer, but we don't get that many hours of darkness.

Well, we get the darkness back, with a vengeance, in November, December, January, February... groan... I don't want to think about that in May!

Ann

About 15 years ago, I took a boat trip across Prince William Sound in Alaska, from Whittier to Valdez (after a bus trip from Anchorage, where the bus drove on to a train and the train-avec-bus drove through a mountain tunnel to Whittier). It was a beautiful summer day and I saw orcas, sea otters and bald eagles all doing their things, as well as some amazing glaciers and mountains. (The harsh climate was said to have helped weather away the residual damage from the Exxon Valdez accident, 10 years prior; it all looked mostly pristine to me.) I asked a deck-hand what they do with the boat in the winter and she replied "we shovel snow off it, to stop it from sinking". I hung around in Valdez, which is an interesting place, and met and got drunk with some local cannery workers. I was not much of a student of astronomy back then, and the Sun just didn't seem to want to set. I left town the next day without sleeping, astoundingly hungover. Ah, nostalgia for a mis-spent youth.

Did anyone see any meteors last night? I was totally clouded out.

BDanielMayfield wrote:Did anyone see any meteors last night? I was totally clouded out.

We were pretty much clouded out as well. In fact, we were trapped in Colorado Springs when they closed the road up the pass because of flood warnings, and had to take a long alternate route, making it a 3 hour return trip, instead of 90 minutes. Got back at midnight. And just captured one Camelopardalid. Didn't see anything visually.

http://asterisk.apod.com/viewtopic.php? ... 16#p226516

A nice ISS pass, just below Polaris, at about 11pm local. 210 second exposure.

Chris Peterson wrote:A nice ISS pass, just below Polaris, at about 11pm local. 210 second exposure.

Nice middle dot, but which way is North?

How close to the ISS's track does one need to be in order to see it well?

BDanielMayfield wrote:How close to the ISS's track does one need to be in order to see it well?

Depends what you mean by well. If you were within 1000 km, I think you'd see it high enough, but it would need to be around dawn or dusk.

BDanielMayfield wrote:How close to the ISS's track does one need to be in order to see it well?

Almost 1000 miles. When it was passing Polaris, it was about 300 miles north of me. Here's the ground track for this pass; the red circle marks where it is 10° above the horizon (Dane House is my location).

A new image of last night's ISS pass, reprocessed to give more accurate color. I also combined all the subs, giving a total exposure of 750 seconds, the central 210 seconds of which show the ISS trail. This creates somewhat longer star trails. Note the very bright red star trail a little to the right of Polaris. That's real. It's HIP 106583, a bright carbon giant. Carbon stars are the only stars that show very saturated color, a consequence of their low temperature (this one is around 3000 K) and peculiar carbon rich atmosphere.