Search found 71 matches
- Thu Nov 03, 2011 3:08 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: IC 59 and IC 63 in Cassiopeia (2011 Nov 03)
- Replies: 22
- Views: 4459
Re: APOD: IC 59 and IC 63 in Cassiopeia (2011 Nov 03)
wow ... you mean there is actually a nebula without a cutsie name attached? you know, the wizard nebula? the heart and soul nebula? the owl nebula? the eskimo nebula? is that even possible? someone has to glom onto this prize bit of unnamed celestial real estate and slap a stupid "looks like a ...
- Sat Oct 29, 2011 4:18 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Spiral Galaxy NGC 3370 from Hubble (2011 Oct 29)
- Replies: 22
- Views: 4864
Re: APOD: Spiral Galaxy NGC 3370 from Hubble (2011 Oct 29)
this is a great topic, glad to see science interest win out with a pretty picture. what is the trend in distance measurement? i think the estimated distance to the andromeda galaxy has been getting smaller, from the estimated 2 million light years distance i remember as a teenager to the circa 800K ...
- Sun Oct 16, 2011 2:43 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Picturesque Venus Transit (2011 Oct 16)
- Replies: 18
- Views: 8032
Re: APOD: A Picturesque Venus Transit (2011 Oct 16)
what is the "viewing clarity" of a camera? i've heard of aperture, focal length, focal ratio, magnification, transmission, resolution and even weird stuff like strehl ratio and zernicke zones ... but viewing clarity? i really have to guess. is that like the weather? the camera doesn't have...
- Sat Oct 01, 2011 2:50 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Asteroids Near Earth (2011 Oct 01)
- Replies: 35
- Views: 6349
Re: APOD: Asteroids Near Earth (2011 Oct 01)
point of english usage: "light" is *visible* electromagnetic radiation. the standard of light is the human eye and the radiation it can detect in most situations. it is incorrect to use the phrase "infrared light" for the same reason it's incorrect to use the terms "xray lig...
- Thu Sep 08, 2011 12:52 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: J102815: A Star That Should Not Exist (2011 Sep 07)
- Replies: 44
- Views: 6712
Re: APOD: J102815: A Star That Should Not Exist (2011 Sep 07
At around mag 17, this star would generally be considered pretty bright. It is orders of magnitude brighter than the SDSS detection limit. thanks, chris. as a visual astronomer i guess i work in a shallower pond. what then is a "faint" star -- mag. 20? how many stars are available to scru...
- Wed Sep 07, 2011 6:54 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: J102815: A Star That Should Not Exist (2011 Sep 07)
- Replies: 44
- Views: 6712
Re: APOD: J102815: A Star That Should Not Exist (2011 Sep 07
this star is very faint ... i cannot find it in the millennium star atlas, not even in stellarium, so it must be below v.mag. 15. my question is how it was identified in the first place, given the time required for even a large aperture scope to collect enough light to do the detailed spectroscopy. ...
- Sun Aug 14, 2011 4:39 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Tornado and Rainbow Over Kansas (2011 Aug 14)
- Replies: 33
- Views: 201493
Re: APOD: Tornado and Rainbow Over Kansas (2011 Aug 14)
looks like another perfect evening for astronomy.
the APOD editorial team has really slipped down the slope of pretty pictures in recent months. i'd prefer that the team first asked themselves, "what specifically does this picture of the day have to do with ... astronomy?"
the APOD editorial team has really slipped down the slope of pretty pictures in recent months. i'd prefer that the team first asked themselves, "what specifically does this picture of the day have to do with ... astronomy?"
- Sun Jul 24, 2011 3:47 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Flight of Helios (2011 Jul 24)
- Replies: 25
- Views: 7666
Re: APOD: A Flight of Helios (2011 Jul 24)
relevance to astronomy: 0%
chances similar technology will be deployed on mars within a century: 0%
out of office messages from APOD selection committee: 100%
chances similar technology will be deployed on mars within a century: 0%
out of office messages from APOD selection committee: 100%
- Tue Jul 19, 2011 3:38 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Vesta Vista (2011 Jul 19)
- Replies: 47
- Views: 6163
Re: APOD: Vesta Vista (2011 Jul 19)
For my money Vesta is a dwarf planet==it has hydrostatic equilibrium. The designation "dwarf planet" is ambiguous enough for Vesta's inclusion in that class. Besides, Vesta is closer to Earth {and more Grecoroman} to be a dwarf planet. Let us make up for poor redenominated Pluto!!! in my ...
- Mon Jul 18, 2011 2:47 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Busy Space Walk at the Space Station (2011 Jul 18)
- Replies: 63
- Views: 23994
Re: APOD: A Busy Space Walk at the Space Station (2011 Jul 1
i've never heard of a space pump before. how long does it take to pump a cubic meter of space?
- Tue May 31, 2011 4:28 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Jets from Unusual Galaxy Centaurus A (2011 May 31)
- Replies: 16
- Views: 3654
Re: APOD: Jets from Unusual Galaxy Centaurus A (2011 May 31)
minor but important point of language: "light" is radiation that can stimulate the human eye to produce a visual sensation. there is no such thing as "xray light" or "microwave light", because these are invisible -- unless one wants to admit "heat light" and &...
- Thu Jan 20, 2011 3:30 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Once and Future Stars of Andromeda (2011 Jan 20)
- Replies: 16
- Views: 2445
Re: APOD: The Once and Future Stars of Andromeda (2011 Jan 2
the half dozen or so unusually bright (large) xray points, excluding the population at the nucleus of the galaxy, are probably multiple, overlapping xray binary signals from inside globular clusters.
- Fri Dec 17, 2010 4:20 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Meteor Moment (2010 Dec 17)
- Replies: 20
- Views: 2104
Re: APOD: A Meteor Moment (2010 Dec 17)
i love national geographic cover art, i really do. but whither apod? readers here often ask some pretty arcane technical questions. but the topics are *scientific*, not "wow, sure is purdy!" why not use the five weekday window as a time machine? * five shots of open star clusters, from the...
- Sun Nov 28, 2010 3:30 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Anticrepuscular Rays Over Colorado (2010 Nov 28)
- Replies: 42
- Views: 4580
Re: APOD: Anticrepuscular Rays Over Colorado (2010 Nov 28)
very nice. but the geometry here actually comes straight out of the renaissance: parallel rays appear to converge to a point, known as the vanishing point. this is a classic central perspective projection. there is an intriguing and turbulent (fluid and chaotically mixed) boundary between art and sc...
- Sun Nov 14, 2010 4:32 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Multiverses: Do Other Universes Exist? (2010 Nov 14)
- Replies: 53
- Views: 6044
Re: APOD: Multiverses: Do Other Universes Exist? (2010 Nov 1
"frequently difficult to test?" UNIFORMLY IMPOSSIBLE to test. i can acknowledge but not approve the contemporary trend in physics to dawdle in the imaginary (string theory) or to hypothesize physical facts that can be experimentally "studied" only in computer simulations (dark ma...
- Wed Nov 03, 2010 7:01 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Necklace Nebula (2010 Nov 03)
- Replies: 46
- Views: 11207
Re: APOD: The Necklace Nebula (2010 Nov 03)
the photo discussion forum would be a great place to post the celestial coordinates and visual magnitude of the object, so that amateur astronomers can place it in relation to the galactic background and the range of objects they are able to see. i infer from its "recently discovered status&quo...
- Sat Oct 02, 2010 3:20 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Hubble s Lagoon (2010 Oct 02)
- Replies: 24
- Views: 4504
Re: APOD: Hubble s Lagoon (2010 Oct 02)
the most striking details about many nebula photographs are the structure shapes that strongly resemble media mixture -- smoke tendrils in air, dye diffusing in water, or bok globules that seem to be the innards of a lava lamp. these complex shapes often have sharply defined boundaries, strong visua...
- Wed Sep 22, 2010 2:48 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Discovery Rollout Shadow (2010 Sep 22)
- Replies: 12
- Views: 3892
Re: APOD: Discovery Rollout Shadow (2010 Sep 22)
i look at that photo and my visceral first reaction as an astronomer? LIGHT POLLUTION! it's everywhere.
- Sun Sep 19, 2010 5:36 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Dark Clouds of the Carina Nebula (2010 Sep 19)
- Replies: 12
- Views: 3240
Re: APOD: Dark Clouds of the Carina Nebula (2010 Sep 19)
"much less dense than earth's atmosphere" ... at what altitude? sea level? 50 miles?
- Wed Sep 01, 2010 3:51 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Earth and Moon from MESSENGER (2010 Sep 01)
- Replies: 69
- Views: 19860
Re: APOD: Earth and Moon from MESSENGER (2010 Sep 01)
i didn't vote for this image and regret that it was posted because it grossly misrepresents both the relative sizes of the earth and moon (because the moon has a higher albedo) and grossly misrepresents the earth/moon distance relative to size. image size of earth = 11 pixels image size of moon = 5 ...
- Sat Aug 07, 2010 4:44 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Rainbow at Sunset (2010 Aug 07)
- Replies: 45
- Views: 5957
Re: APOD: Rainbow at Sunset (2010 Aug 07)
one aspect of the rainbow geometry: for each rainbow observer, the center of the circle implied by the rainbow arc is always at the solar shadow of the observation point, which in this case appears to be the top of the observation dome shadow cast on the ground, just below the wall of the small whit...
- Tue Jun 08, 2010 3:00 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Falcon 9 Launches to Orbit (2010 Jun 08)
- Replies: 70
- Views: 8097
Re: APOD: Falcon 9 Launches to Orbit (2010 Jun 08)
it's a wasp, probably a yellowjacket. observe the downward curl in the tips of the antennae. the head and thoracic segment are greatly enlarged in comparison to the abdomen due to extreme foreshortening. but it's a wasp.
- Fri Jun 04, 2010 4:31 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Hubble Remix: Active Galaxy NGC 1275 (2010 Jun 04)
- Replies: 42
- Views: 5187
Re: APOD: Hubble Remix: Active Galaxy NGC 1275 (2010 Jun 04)
i recommend the photos posted on a page linked from a page linked in the photo caption ... details of the "tentacles":
http://www-xray.ast.cam.ac.uk/papers/ngc1275/
http://www-xray.ast.cam.ac.uk/papers/ngc1275/
- Wed Jun 02, 2010 7:04 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
- Replies: 157
- Views: 13686
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
This image has been widely discussed in the meteoritics community. The consensus (unanimous as far as I've seen) is that the camera got jarred by wind or maybe an animal. The same effect has been seen on other images where that happened. That doesn't jive with larger bolides pretty much all observe...
- Wed Jun 02, 2010 1:59 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
- Replies: 157
- Views: 13686
Re: APOD: A Twisted Meteor Trail Over Tenerife (2010 Jun 02)
JLo, exSquid: the "second meteor" is an enlarged inset image of the first (there is only one meteor), and the camera is on a clock drive, which tracks the moving stars. the useful point of information would be to calculate the spatial variance implied by the "wobble". an eyeball ...