Starship Asterisk*

> toward the constellation Vulpecula. should be Pisces, I suppose. Why should you suppose that? http://heritage.stsci.edu/2013/09/fast_facts.html http://www.spacetelescope.org/videos/heic1304a/ http://simbad.u-strasbg.fr/simbad/sim-id?Ident=aco+68 Hmm, seems STScI may be in error here. The coordina...

The label 3 galaxy looks so unusual! Is there another galaxy closer that looks similar? Not as extreme as this, but there are some other examples of ram-pressure stripping caught in the act in clusters: C153 in Abell 2125 ( more details ) NGC 4388 and NGC 4522 in the Virgo cluster. (Plus more in th...

And thank you also, NGC3314. With two photographers here, can I give a quote from my own initial post and ask for your input? Doubly ionized oxygen, [O III] emits light in the green part of the spectrum primarily at the wavelength 500.7 nanometres (nm) and secondarily at 495.9 nm. The information g...

It's true that broadband filters will detect any of the emission lines that narrow band filters do. However, there is a caveat to that, in that you would reach a sky limited exposure long before picking up enough of those emissions. Narrow band filters allow you take much longer exposures, in fact,...

In it, Voyager's wide angle camera frames sweep through the inner Solar System at the left, linking up with gas giant Neptune, at the time the Solar System's outermost planet, at the far right. :roll: It''s not that bad. Pluto was near perihelion in 1990, and passed Neptune's distance from the Sun ...

Are there any estimates out there of how much of the universe is thought to be dust ? APOD pics frequently mention it, but has it been quantified ?? A quick google didn't actually turn up any numbers. In spiral galaxies, several techniques find that the dust mass is about 0.6% of the gas mass (atom...

The classical Einstein ring is an idealization, in the case of an extended object located exactly behind a lensing mass which is circularly symmetric about an axis matching our line of sight. For a circular lens, increasing misalignment will first make the ring uneven (brightest at two opposite area...

That's a somewhat unfortunate phrasing - the core of the lensing galaxy is not completely obvious in this image, but it is visible. To see it more clearly, here's a display of some archival Hubble data.

Since we're on the subject Pismis clusters - I'm old enough to have met Paris Pişmiş when she was still frequently at meetings. She was born in Turkey and emigrated to Mexico, where she played an important role in building up their astronomical infrastructure (especially at the Universidad Autonoma ...

In the 1950's as a result of It's unnatural-looking, elongated shape, the huge indentation carved out at one end had the USSR conclude that Phobos was a space station built by an advanced civilization inhabited on Mars. It's likeness reminiscent of a potato has a certain appearance that easily play...

Like may supernova remnants in its age range, Simeis 147 does have reasonably strong [O III] emission (I found a paper in a Soviet journal from the 1970s quoting ratios of 2.0-4.6 relative to the strength of H-beta). As well as by reprocessing deep UV, these transitions can also be powered by rapid ...

Both Shuttle Carrier Aircraft are slated to become spare-parts sources for the SOFIA observatory.

At solar max, my zenithal sky brightness is 20.8 mag/arcsec^2; at solar min, it is 21.3, so there is quite a range (very obvious visually) in background brightness. The contribution from dust is constant (I can see the gegenschein at both solar min and solar max). Oh, sure, rub it in about having d...

People have asked here before about how many more stars you might see from space, or from the surface of the Moon. The answer is not much more than you see from the ground, since our atmosphere doesn't attenuate the stars very much. But without airglow, the space between the stars, seen from space,...

George5 wrote:Can we stop having those distortion effects like star filters which give those spikes coming out of the bright stars and ruining the realistic effect?

The causes of those effects are commonly known as reflecting telescopes. Deconvolution processing would be required to remove this effect.

Also on another note. Why is it that the reflecting of light, sun light, or stars through a lens alway either emit 6 or 8 sides either like a hexagon or in the case of this new star six lines ejecting out from the star. Sometimes on tv the reflections of light or mist show an actual hexagon or octo...

For some reason I can't quite wrap my mind around the idea that you measure the distance to the Sun with the help of the Venus passage. I don't doubt, however, that it can be done, and that it can be explained, too, to someone who is less dense when it comes to mathematics than I am. This is a way ...

What is the chance of such alignments happening given the number density of galaxies, particularly as we go deeper in the universe at higher redshifts ? Could such alignments have resulted in improperly recognizing the shapes of the galaxies at higher redshifts ? The Galaxy Zoo project, as a spinof...

One serious question: Why have they almost always opened the bay doors early in the mission? Is there a cooling issue, or is there some other reason, such as making a shuttle more visible to observers? Cooling - there are large radiators attached to the inner sides of the doors, and if for some rea...

I swoon in admiration! (I've worked with those data, originally taken for a gravitational-microlensing search, but never managed such a nice color representation). The synthetic third channel rises from the fact that these data were taken in only two filters (B and V, more or less). Galaxy colors ar...

The galaxy pair at far right was the subject of a Hubble image release in September 2008, dealing with analysis of the dust in the foreground galaxy. (I thought this had been an APOD itself, but can't find it with a quick search). They are not actually interacting - new H I data indicate that the fo...

Oops, that "Guest" above was from me. I didn't notice until later that I had not auto-logged in.

Bill Keel

It's a great image of an interesting and certainly uncommon object! Some obvious basic questions: - Why should there be SO much oxygen? I thought oxygen was a byproduct of supernovae. Did a bunch of them explode all at once out there? There's not, relatively speaking - only about a quarter of the s...

The Voorwerp itself is very green (at least on my monitor), since that band is dominated very strongly by [O III] except for a few small regions with enough H-alpha to make it orange - elsewhere in the Voorwerp, the [O III] lines are about 5 times as strong as H-alpha and correspondingly stronger th...

Not to be too much of a tease - but the Hubble images of Hanny's Voorwerp will be released in one week. There are interesting new details in both the Voorwerp and IC 2497 (like that would be a big surprise!)