Search found 1078 matches

by VictorBorun
Sun Dec 10, 2023 10:31 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Perseus Galaxy Cluster from Euclid (2023 Nov 08)
Replies: 49
Views: 133303

Re: APOD: Perseus Galaxy Cluster from Euclid (2023 Nov 08)

that is a good news. Of course it depends on how correct we model the forming of rogue asteroids and Oort clouds. We can't see or radar them now and they can be more numerous for all we know. Or can we see them after all, not in their star's light, but in the stellar wind of a Nova or Supernova? he...
by VictorBorun
Sat Dec 09, 2023 9:57 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Perseus Galaxy Cluster from Euclid (2023 Nov 08)
Replies: 49
Views: 133303

Re: APOD: Perseus Galaxy Cluster from Euclid (2023 Nov 08)

Exactly. The total mass of the Oort cloud is probably on the order of a few Earths, which is distributed over a massive volume. We could probably sail a probe around in the Oort cloud for thousands of years and never come close enough to a body to detect it. Two Oort clouds passing through each oth...
by VictorBorun
Sat Dec 09, 2023 8:54 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Andromeda over the Alps (2023 Nov 13)
Replies: 21
Views: 34941

Re: APOD: Andromeda over the Alps (2023 Nov 13)

From over 2 million years ago. What we "see" is what light shows us and light emitted from stars/planets/life on planets in same galaxy is all same. It takes 2+ millions years for light to reach us from there. So, no one knows what happened later (during those 2+ million years when light ...
by VictorBorun
Sat Dec 09, 2023 8:49 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Plane Crossing Crescent Moon (2023 Dec 04)
Replies: 18
Views: 12163

Re: APOD: Plane Crossing Crescent Moon (2023 Dec 04)

More like this https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRC5aOrphDcGCszC7sdRo3fl6sQDq7cG8AK2cQDcWfdCj_6G-4AYNb9C-G_JeTK951F5Mc&usqp=CAU The disk of the moon when low above the horizon should be red. Like when it's a narrow crescent close to the disk of the sun and the sun is low abo...
by VictorBorun
Thu Dec 07, 2023 12:06 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Plane Crossing Crescent Moon (2023 Dec 04)
Replies: 18
Views: 12163

Re: APOD: Plane Crossing Crescent Moon (2023 Dec 04)

More like this https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRC5aOrphDcGCszC7sdRo3fl6sQDq7cG8AK2cQDcWfdCj_6G-4AYNb9C-G_JeTK951F5Mc&usqp=CAU The disk of the moon when low above the horizon should be red. Like when it's a narrow crescent close to the disk of the sun and the sun is low abo...
by VictorBorun
Tue Dec 05, 2023 11:44 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Energetic Particle Strikes the Earth (2023 Dec 05)
Replies: 16
Views: 8784

Re: APOD: Energetic Particle Strikes the Earth (2023 Dec 05)

Do we know for certain that this was indeed a single high energy particle ? And not a whole 'cohort' of particles - arriving together ?? Indeed, Photographing such an event is going to present some challenges This should snapshot individual high energy particles creating a shower in the atmosphere
by VictorBorun
Mon Nov 13, 2023 5:37 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Andromeda over the Alps (2023 Nov 13)
Replies: 21
Views: 34941

Re: APOD: Andromeda over the Alps (2023 Nov 13)

IF we had a telescope that was powerful enough to see all the way into the Andromeda galaxy, and powerful enough to zoom into a planet that harbored some type of life, would we be seeing images from 2 million years ago or current? From over 2 million years ago. What we "see" is what light...
by VictorBorun
Mon Nov 13, 2023 5:17 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Perseus Galaxy Cluster from Euclid (2023 Nov 08)
Replies: 49
Views: 133303

Re: APOD: Perseus Galaxy Cluster from Euclid (2023 Nov 08)

Wikipedia says our own Oort cloud extends to "distances ranging from 2,000 to 200,000 AU (0.03 to 3.2 light-years)". If another star with a similar Oort cloud passes with, say, 1 ly, the two Oort clouds would pass through each other. So, you're saying that although the gravity of the pass...
by VictorBorun
Sun Nov 12, 2023 8:28 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Perseus Galaxy Cluster from Euclid (2023 Nov 08)
Replies: 49
Views: 133303

Re: APOD: Perseus Galaxy Cluster from Euclid (2023 Nov 08)

Here is a simulation of a major merger resulting in the formation of a large elliptical galaxy. Stars are shown in the left, gas temperature at the right. https://www.illustris-project.org/movies/illustris_movie_elliptical_formation_1pMpc.mp4 Certainly from the perspective of an individual star and...
by VictorBorun
Tue Nov 07, 2023 10:28 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Dinkinesh Moonrise (2023 Nov 04)
Replies: 16
Views: 19026

Re: APOD: Dinkinesh Moonrise (2023 Nov 04)

There is no evidence of "exploded planets" in the Solar System (and no physics to explain such a thing). Asteroids are remnants of material that failed (probably due to gravitational resonance zones created by the gas giants) to coalesce into planets. The total mass of all the asteroids i...
by VictorBorun
Wed Oct 25, 2023 12:18 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Moon Io from Spacecraft Juno (2023 Oct 23)
Replies: 17
Views: 24382

Re: APOD: Moon Io from Spacecraft Juno (2023 Oct 23)

to judge the colour, we can take this pic https://upload.wikimedia.org/wikipedia/commons/5/5c/PIA25726-Jupiter%2BMoonIo-Juno-20230731.jpg and try saturation slider like this Io Saturation+30.jpg there seem to be some pinkish regions and some greenish regions and that can be thought as a struggle of ...
by VictorBorun
Sun Oct 15, 2023 4:31 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: An Eclipse Tree (2023 Oct 15)
Replies: 9
Views: 12316

Re: APOD: An Eclipse Tree (2023 Oct 15)

…I used to be taken driving and notice the speckled shadows moving across the carriage, before it occurred to me that they were caused by the leaves overhead. (As soon as I discovered this, the scientific interest killed the impression, and I began speculating as to why the patches of light were alwa...
by VictorBorun
Sun Sep 17, 2023 6:37 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Moon Mountains Magnified during Ring... (2023 Sep 17)
Replies: 16
Views: 3034

Re: APOD: Moon Mountains Magnified during Ring... (2023 Sep 17)

Sa Ji Tario wrote: Sun Sep 17, 2023 3:05 pm On one side of the lunar limb are the DÁlambert Mountains that look like saw teeth and through whose ravines and valleys sunlight filters to form the Baily Beads.
please which side is the one side?
by VictorBorun
Thu Sep 14, 2023 5:30 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: NGC 7331 and Beyond (2023 Sep 14)
Replies: 21
Views: 4148

Re: APOD: NGC 7331 and Beyond (2023 Sep 14)

is it me or the core is quite spherical?
NGC 7331 and Beyond.JPG
NGC 7331 and Beyond-.JPG
...
Click to view full size image 1 or image 2
by VictorBorun
Sun Sep 03, 2023 6:38 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)
Replies: 60
Views: 17501

Re: APOD: NGC 7023: The Iris Nebula (2023 Sep 02)

do I get it right: this is a dust cloud dimly backlighted by many distant stars, as can be seen at the edges of this APOD frame (and showing dark gray with a brown tint) brightly backlighted by a single star closely behind the dust cloud (in pale cyan to blue to deep violet as the angle of scatterin...
by VictorBorun
Thu Aug 31, 2023 5:37 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Crew-7 Nebula (2023 Aug 31)
Replies: 13
Views: 3396

Re: APOD: The Crew-7 Nebula (2023 Aug 31)

are colours real?
how long is the exposure?
is the ring a true ring in 3d space or just a light echo looking like a ring from the point of view?
by VictorBorun
Wed Aug 16, 2023 11:54 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Sombrero Galaxy in Infrared (2023 Aug 13)
Replies: 23
Views: 8575

Re: APOD: The Sombrero Galaxy in Infrared (2023 Aug 13)

Beautiful image! But it looks like the central region of this galaxy is pretty empty of stars - is this really the case? It's an illusion. The central region is nothing but stars! Thanks, Chris. When I look at this flat image, a 2-dimensional elliptical region, or oval, appears to be the main illum...
by VictorBorun
Mon Aug 07, 2023 5:30 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)
Replies: 29
Views: 8554

Re: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)

The egg shell has a pretty uniform hue. The image of the egg does not because of the intensity variations. Even with a hue created by a very narrow wavelength, there is no single color (or meaningful RGB representation) because the actual color is defined by intensity as well as hue. here's a fragm...
by VictorBorun
Sat Aug 05, 2023 10:11 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)
Replies: 29
Views: 8554

Re: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)

neither the Robin's Egg Nebula nor a robin's egg have a colour hue or a wavelength. Both look like some indigo ink that thickens white to pale cyan to blue to dark violet to black. The egg shell has a pretty uniform hue. The image of the egg does not because of the intensity variations. Even with a...
by VictorBorun
Sat Aug 05, 2023 9:22 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)
Replies: 29
Views: 8554

Re: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)

https://apod.nasa.gov/apod/image/2308/ngc1360_v2_1024.jpg https://www.10000birds.com/wp-content/uploads/2008/05/robin-egg.jpg Yes, I guess the turquoise color of robin's eggs is a good proxy for the blue-green color of many planetary nebulas. A robin's egg is never likely to show any large patches ...
by VictorBorun
Sat Aug 05, 2023 9:20 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)
Replies: 29
Views: 8554

Re: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)

At the time when Sirius A becomes a white dwarf, Sirius B will still be a white dwarf orbiting their common center of mass. And the planetary nebula that will be created by Sirius A will envelop Sirius B, too. So that's what Sirius will become for a short time in the future, a binary white dwarf in...
by VictorBorun
Sat Aug 05, 2023 6:48 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)
Replies: 29
Views: 8554

Re: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)

A robin's egg is never likely to show any large patches of pink, however. Ann the alien conspirator who went 1500 years back in time and 1500 ly away to create the Robin's Egg Nebula got somewhat confused: they correctly understood the phrase your eyes were bluer then robin's eggs but failed to see...
by VictorBorun
Sat Aug 05, 2023 6:39 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)
Replies: 29
Views: 8554

Re: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)

I guess they started out as a normal binary star, after which first one and then the other of the two "less than 8 solar masses components" used up their available fuel, shed their outer layers and became the "central double star" of a planetary nebula. Ann what are the chances ...
by VictorBorun
Sat Aug 05, 2023 4:31 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)
Replies: 29
Views: 8554

Re: APOD: NGC 1360: The Robin's Egg Nebula (2023 Aug 05)

I wonder how can two stars in a binary system go together hot new white dwarfs
by VictorBorun
Thu Aug 03, 2023 9:56 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Falcon and the Redstone (2023 Aug 03)
Replies: 21
Views: 5903

Re: APOD: The Falcon and the Redstone (2023 Aug 03)

a retrograde GSO, would return to the same point in the sky more often (or less often???) than once per Earth rotation. Hmm, in the simplest case of zero eccentricity and zero inclination, what would the path of such an object be as seen from the ground and how often would it return to the same pos...