Search found 13219 matches

by Ann
Fri May 31, 2024 2:16 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Nebulous Realm of WR 134 (2024 May 31)
Replies: 32
Views: 5016

Re: APOD: The Nebulous Realm of WR 134 (2024 May 31)

But why they occur in binary systems? And why their companion is most likely a compact object? Given that something like 85% of high mass stars are part of binary systems, maybe the question to ask is why only 50% of WR stars are binaries? OK, so I ask: Why 85% of high mass stars are part of binary...
by Ann
Fri May 31, 2024 2:06 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Nebulous Realm of WR 134 (2024 May 31)
Replies: 32
Views: 5016

Re: APOD: The Nebulous Realm of WR 134 (2024 May 31)

a Wolf-Rayet nebula is primarily shaped by the tremendous heat and wind of its own central star Ann I have trouble getting my head wrapped round the way that things work on these scales. If the nebula has something like a 40 light year radius, does that mean that the glow from the nebula has actual...
by Ann
Fri May 31, 2024 6:34 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Nebulous Realm of WR 134 (2024 May 31)
Replies: 32
Views: 5016

Re: APOD: The Nebulous Realm of WR 134 (2024 May 31)

I find it a little irritating that this APOD is so large that I have to post it here as an attachment! NebulousRealmofWR134_1024[1].png The Nebulous Realm of WR 134. Image Credit & Copyright: Xin Long What I really like about this image is that it doesn't just show us that bright and slightly to...
by Ann
Thu May 30, 2024 5:16 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Lunar Corona over Paris (2024 May 30)
Replies: 12
Views: 1802

Re: APOD: A Lunar Corona over Paris (2024 May 30)

Wow, what a c o l o r b o m b ! :shock: https://apod.nasa.gov/apod/image/2405/EiffelCorona_Binotto_960.jpg Well, I have seen colorful lunar coronas myself, but never anything like this! :shock: And just look at how that intensely blue narrow laser beam of light emitted from the gold-illuminated Eiff...
by Ann
Wed May 29, 2024 7:08 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Stairway to the Milky Way (2024 May 29)
Replies: 11
Views: 1506

Re: APOD: Stairway to the Milky Way (2024 May 29)

Or perhaps it is NGC 3603 (and maybe NGC 3576) that are the bar-end enhancements of the southern Milky Way? Well, we are still in Carina. Do the distances (from Wikipedia) to NGC 3603 (20,000 ly) and NGC 3576 (9,000 ly) jibe with either or both of them being physically in the "bar-end"? E...
by Ann
Wed May 29, 2024 3:04 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Stairway to the Milky Way (2024 May 29)
Replies: 11
Views: 1506

Re: APOD: Stairway to the Milky Way (2024 May 29)

Sa Ji Tario wrote: Wed May 29, 2024 2:19 pm Is the object under the letters "Air Glow" Andromeda?
Yes, it looks like that! :D

Ann
by Ann
Wed May 29, 2024 5:48 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Stairway to the Milky Way (2024 May 29)
Replies: 11
Views: 1506

Re: APOD: Stairway to the Milky Way (2024 May 29)

Yes, that's a nice Milky Way image (with stairs)! :D https://apod.nasa.gov/apod/image/2405/StairwayToMilkyway_Marcin_1080_annotated.jpg Me being me, I obviously love the blue zing of bright star Vega at top! 💙 But I'd also like to call your attention to the reddish patch of nebulosity around Deneb: ...
by Ann
Tue May 28, 2024 5:26 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Chamaeleon I Molecular Cloud (2024 May 27)
Replies: 10
Views: 1549

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

mjsakers wrote: Tue May 28, 2024 3:17 pm I'm interested in the name of the distant galaxy seen to the right of the cloud in the photo (?)
The galaxy in question may be ESO 38-6.

It is more or less in the right place.

Ann
by Ann
Tue May 28, 2024 4:56 pm
Forum: The Asterisk Café: Discuss Anything Astronomy Related
Topic: Did this black hole form without a supernova - and does it explain vanishing stars?
Replies: 3
Views: 4292

Re: Did this black hole form without a supernova - and does it explain vanishing stars?

Thanks for this most interesting link! I wonder if another consideration that might support the idea of stars vanishing into back holes is that of supernovae (type II) as rebounds - what's there to rebound against when a star collapses into a black hole? (might the two even be related - no rebound,...
by Ann
Tue May 28, 2024 5:20 am
Forum: The Asterisk Café: Discuss Anything Astronomy Related
Topic: Did this black hole form without a supernova - and does it explain vanishing stars?
Replies: 3
Views: 4292

Did this black hole form without a supernova - and does it explain vanishing stars?

DID THIS BLACK HOLE FORM WITHOUT A SUPERNOVA? https://dq0hsqwjhea1.cloudfront.net/binary-black-hole-O-star.webp Colin Stuart of Sky & Telescope wrote: Some massive stars may collapse completely into black holes — without the fanfare of a supernova. An international team of astronomers has revea...
by Ann
Mon May 27, 2024 7:26 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Chamaeleon I Molecular Cloud (2024 May 27)
Replies: 10
Views: 1549

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

Today's APOD is great and so are your wonderful explanations. Thank you very much Ann! https://live.staticflickr.com/65535/53750637031_a4164b1742_b.jpg Background picture: Chamaeleon I Molecular Cloud Image Credit & Copyright: Amiel Contuliano https://www.astrobin.com/32d8tb/ https://planetary....
by Ann
Mon May 27, 2024 6:39 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Chamaeleon I Molecular Cloud (2024 May 27)
Replies: 10
Views: 1549

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

Cederblad111-110_1024[1].jpg Chamaeleon I Molecular Cloud Image Credit & Copyright: Amiel Contuliano No one has had anything to say about today's APOD, eh? Well, it's a nice picture of a very young region of low-mass star formation. Actually I shy away a little from the expression "low-mas...
by Ann
Sun May 26, 2024 4:05 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Solar Filament Erupts (2024 May 26)
Replies: 13
Views: 1310

Re: APOD: A Solar Filament Erupts (2024 May 26)

How about showing the UV Sun as purple? I don't understand those who say that it would be horribly wrong to show the UV Sun as purple, but OK to show it as orange. Here's another pseudocolor palette example, using today's Sun image. I think that, objectively, the palette they've chosen allows us to...
by Ann
Sun May 26, 2024 2:52 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Solar Filament Erupts (2024 May 26)
Replies: 13
Views: 1310

Re: APOD: A Solar Filament Erupts (2024 May 26)

It's not my kind of image either, partly because I tend not to be all that enthusiastic about pictures of the Sun, but mostly because it really irks me that the Sun is shown as orange. The image appears to be constructed from a single channel of data made by selecting the brightest pixels in a stac...
by Ann
Sun May 26, 2024 2:30 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Solar Filament Erupts (2024 May 26)
Replies: 13
Views: 1310

Re: APOD: A Solar Filament Erupts (2024 May 26)

https://apod.nasa.gov/apod/image/2405/filament_sdo_960.jpg This image hasn't generated a lot of traffic. It's not my kind of image either, partly because I tend not to be all that enthusiastic about pictures of the Sun, but mostly because it really irks me that the Sun is shown as orange. Again. Co...
by Ann
Sat May 25, 2024 5:10 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Manicouagan Impact Crater from Space (2024 May 25)
Replies: 14
Views: 3057

Re: APOD: Manicouagan Impact Crater from Space (2024 May 25)

Lots of interesting questions arise! How accurate are age estimates? The text says 215 million years, 1 million years plus or minus, so cannot have caused Triassic-Jurassic die-off at 201 million years. Percentage of error possible at that remove, for each estimate? Also, where was Quebec back then...
by Ann
Sat May 25, 2024 4:13 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: M78 from the Euclid Space Telescope (2024 May 24)
Replies: 10
Views: 2727

Re: APOD: M78 from the Euclid Space Telescope (2024 May 24)

[...] The purple color of M78 in today's APOD was caused by the artistic choices of the people processing the image. The filters chosen for image may also have something to do with the palette of the final product. [...] Ann ... In principle, the Euclid color palette can be transferred very easily ...
by Ann
Fri May 24, 2024 9:04 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: M78 from the Euclid Space Telescope (2024 May 24)
Replies: 10
Views: 2727

Re: APOD: M78 from the Euclid Space Telescope (2024 May 24)

Blue star light does not make purple reflection nebulas! 🤬 Ann The info on the ESA site says The blue, green, red channels capture the Universe seen by Euclid around the wavelength 0.7, 1.1, and 1.7 micron respectively. This gives Euclid a distinctive colour palette: hot stars have a white-blue hue...
by Ann
Fri May 24, 2024 5:54 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: M78 from the Euclid Space Telescope (2024 May 24)
Replies: 10
Views: 2727

Re: APOD: M78 from the Euclid Space Telescope (2024 May 24)

https://apod.nasa.gov/apod/image/2405/M78_Euclid_960.jpg APOD Robot wrote: ESA's new Sun-orbiting Euclid telescope recently captured the most detailed image ever of the bright star forming region M78. Really? Is that because this is a combined optical and infrared image? The purple tint in M78's ce...
by Ann
Fri May 24, 2024 4:54 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Unraveling NGC 3169 (2024 May 23)
Replies: 11
Views: 2262

Re: APOD: Unraveling NGC 3169 (2024 May 23)

This galaxy looks very unique to me. I am a student of galaxies, these look brand new to me. There appear to be ~3 rings around NGC 3169 perpendicular to its plane of rotation. Has the other galaxy circled it that many times? I would love to see the simulation of these 2 galaxies interacting. Note,...
by Ann
Thu May 23, 2024 7:14 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Unraveling NGC 3169 (2024 May 23)
Replies: 11
Views: 2262

Re: APOD: Unraveling NGC 3169 (2024 May 23)

So, I'm reading that tiny NGC 3165 is also part of this triple, and at about the same distance, yet it doesn't seem to be interacting with the other two at all, either currently or in the past. Why not? Also, I note that NGC 3165 is classified as a spiral too, which would confirm that spirals reall...
by Ann
Thu May 23, 2024 6:02 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: CG4: The Globule and the Galaxy (2024 May 21)
Replies: 6
Views: 1977

Re: APOD: CG4: The Globule and the Galaxy (2024 May 21)

ThanX Ann Your hypothesis regarding gamma velorum is bold, but I also think correct. Regarding the two YSOs, I find MASS_J073439.9-465548 (1) particularly noteworthy. This seems to be in an intermediate stage and is almost floating freely in space. According to the classical view, stripped of its d...
by Ann
Thu May 23, 2024 7:16 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Unraveling NGC 3169 (2024 May 23)
Replies: 11
Views: 2262

Re: APOD: Unraveling NGC 3169 (2024 May 23)

N3169N3166Final1024[1].jpg Unraveling NGC 3169 Image Credit & Copyright: Christophe Vergnes, Aziz Kaeouach NGC 3169 and NGC 3166 are indeed an interesting pair of galaxies! They used to be normal spiral galaxies for sure, but now one of them (NGC 3169) is indeed "unraveling", and the ...
by Ann
Wed May 22, 2024 7:50 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Green Aurora over Sweden (2024 May 22)
Replies: 10
Views: 2393

Re: APOD: Green Aurora over Sweden (2024 May 22)

It seems obvious to me that it is harder to create a blue nitrogen aurora than a green or a red oxygen one. Since the blue aurora is so rare, it has to require a lot of energy to create it. But in the many pictures of auroras that have been submitted to Starship Asterisk* and other sites from the l...
by Ann
Wed May 22, 2024 2:24 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Green Aurora over Sweden (2024 May 22)
Replies: 10
Views: 2393

Re: APOD: Green Aurora over Sweden (2024 May 22)

I’m having a hard time finding a coherent explanation of what causes the different colors. O2 molecules split because of ultraviolet light, then the O atom picks up an “ambient” electron, (not from the sun , only “particles” come from the sun, not protons and electrons) causing emission of green li...