Starship Asterisk*

sunson wrote:Given the curvature of the surface, I would think the shadow should look oval !!! Not round, unless you are right on the line of sight from the sun.

There's a good illustration of this from a very different viewpoint in this sequence of JunoCam images of Ganymede's shadow.

What is that incomplete loop just south of Gamma Leporis? A quick check of a deep-sky atlas and some Googling doesn't turn up an obvious celestial ID.

A background note - if I can tear my eyes away from the intricate structure of Centaurs A, near the lower right corner is the galaxy pair NGC 5090/91, of which the elliptical component NGC 5090 is itself the center of a large double radio source. Galaxies stretching away for gigaparsecs and gigapars...

I didn't know that Cygnus X-1 was called a microquasar. I thought it was just a black hole. Is that a new designation? Microquasars are black holes or neutron stars which are remnants of stellar collapse, which are accreting and producing relativistic jets (hence the analogy to quasars). The first ...

59 and hoping for my second, after Oregon in 1979. To add to the point about it being maybe the most-photographed event, I put together this montage of images (taken uniformly from a set of 35mm slides) from the 1979 event, showing the enormous range in brightness from prominences to the corona, so ...

This is a dusty region overall, almost exactly along the plane of the Milky Way's disk. Right at the bottom of this view are the two nearby galaxies Maffei 1 and 2, so strongly reddened by our local dust that they are dimmed by something like a factor 100 in visible light.

JohnD wrote:What are the four towers around the launch site for?
John

Basically lightning rods (here's a paper describing the systems at some of the pads).

Most edge on pictures I have seen have tons of dust lanes where we can't see the light and beauty of the stars/clusters in the plane of the galaxy. I wonder why there's not much dust in this one and is that unusual or normal .. Very broadly, the dust organization changes between large, massive spir...

I took this to mean they orient the entire structure using reaction wheels. That's the range over which they can tilt the sunshield and keep the instrument in shade and the solar panel and antenna pointed within spec. Looking at the tower the telescope is mounted on, I don't see any mechanism for t...

Will the JWST be able to point opposite its sunshield and the Sun? Unless the mirror can change elevation angle with respect to the sunshield, it seems it might be difficult. I can't see any pics with the mirror pointing away from the sunshield. The sunshield appears to be designed to allow the mir...

Those outer features are pretty blue. They're blazingly bright in the UV. There was a GALEX press release, but the only graphic they had (AFAICT) was an optical-UV comparison that didn't make this visually clear. So here's the GALEX UV color image (yellow=near-UV, 2400 A, blue=far-UV at 1500 A). One...

In the DISCOVR video of the moon's shadow crossing the Earth, why is the shadow so diffuse? I understand the Earth's atmosphere scatters the light, but that should only be apparent from the ground. From space, it seems that the edges of the moon's shadow should be quite distinct. Or is it just a fu...

I'm confused and disappointed that there aren't any shots of this supernova taken by any of the "big guns' like Hubble, Keck, etc. Why not? There has been a report of Keck near-infrared observations using adaptive optics to get the most accurate position they could, in hopes of using old HST i...

I'm going to have to argue with Chris on some of those points. There are indeed pushes for bigger optical/UV instruments (sample) - but to significantly improve on Hubble's performance, it has to be a big jump and a flagship-class mission that comes up in the budget only every 15-20 years (so, have ...

Hitomi's real strength should be in high-resolution spectroscopy. It carries a precision device which has been a long time coming - first it was slated for Chandra but was lost to a "descope"[1]. Then it was supposed to fly on Astro-E which would up in the Pacific due to booster failure. T...

Rainbows need not always appear to be very far away. On one particularly wet day in California, I saw a rainbow between my eyes and the far side of the road I was walking along.

Some of the IFN seen immediately around M82 may in fact belong to it. There was a polarization study with the 8m Subaru telescope showing that some of the emission-line radiation in the bright filaments is scattered from dust particles in the outlawing wind, which makes it also possible that regions...

67P is the sixth comet we've had a close look at (the previous ones from flyby missions). Emily Lackdawalla put together a scale montage. The most common shape seems to be like a bowling pin; maybe that's related to the distinct double lobes of 67P? Halley almost looks as double from certain angles.

Pace today's APOD, Proxima Centauri is not unusually faint. Its apparent magnitude is 11 and it can be seen in a small telescope. What was discovered in 1915 was its closeness to us rather than its existence. To point that up - these images were done during class projects using a remotely operated ...

I always look out for background galaxies in galaxy images! I like 2MASX J00482185-2507365 . It can be seen near the bottom right corner of this image of NGC 253 by CHART32 . That object showed up with obvious dust absorption in the ANGST Hubble survey of halo stars in nearby galaxies including NGC...

No (and if there were one I would have had to write it). I have Tweeted pretty much all the images as they came in, and the program status information can be seen here . "Proposal information" and "visit status" links are, to my mind, the most helpful. 54 targets so far, but no m...

M96 contains the background galaxy of all background galaxies, a beautifully edge-on, largish, flat, reddish spiral galaxy perfectly aligned with a spiral arm of M96! That's a good one, but I must respectfully disagree about the superlative. There's, umm, NGC 3314 itself, and the gigantic edge-on g...

Why not THE SUN as a source?? The majority of Neutrinos come from Nuclear Reactions in The Sun....why not The Sun???? The Sun is a known neutrino source, but its neutrinos are at much lower energies than IceCube detects - its working technique (Cherenkov radiation) works at crazily high energy, in ...

Cassini does not have enough fuel for such dramatic maneuvers - most of the velocity change for its endgame mission plan comes from carefully timed encounters with Titan. One of them has to be close enough to change its closest orbital point from outside to inside the main rings in one jump. The gia...

Does the image of the Crab Nebula show any significant (visible) change during the passage of weeks, months or years? In addition to the expansion and gradual changes in outer filaments shown in that caparison, there are much faster changes due to the pulsar wind very close to it - here is a compar...