Search found 1102 matches
- Sat Apr 06, 2024 3:43 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Unusual Nebula Pa 30 (2024 Apr 03)
- Replies: 15
- Views: 1696
Re: APOD: Unusual Nebula Pa 30 (2024 Apr 03)
I found a diagram that applies to the high temperature, high pressure scenario of a supernova: https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQnOo5HRQcWqFvAXdS870Vf-ti_vF8V-dRXI2NtzzZ-fw&s Source: https://isnap.nd.edu/assets/250195/radioactivity_lecture_10.pdf I think I get it… still, wh...
- Wed Apr 03, 2024 5:55 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Unusual Nebula Pa 30 (2024 Apr 03)
- Replies: 15
- Views: 1696
Re: APOD: Unusual Nebula Pa 30 (2024 Apr 03)
With a temperature near 200,000 K, WD J005311 is the hottest star known. The extreme properties of the central star are being powered by the residual radioactive decay of ⁵⁶Ni, where the usual half-life of 6.0 days from electron capture is increased to many centuries due to the nickel being complet...
- Sat Feb 03, 2024 9:37 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: NGC 1365: Majestic Island Universe (2024 Feb 01)
- Replies: 19
- Views: 536002
Re: APOD: NGC 1365: Majestic Island Universe (2024 Feb 01)
More important still might be the way that the bar, specifically the dust lanes in the bar, feed gas into the central black hole of a barred galaxy. By what mechanism? Is the dust and gas in the bar so dense it behaves like a viscous liquid, resulting in particles losing energy and spiraling inward...
- Sat Feb 03, 2024 12:11 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: NGC 1365: Majestic Island Universe (2024 Feb 01)
- Replies: 19
- Views: 536002
Re: APOD: NGC 1365: Majestic Island Universe (2024 Feb 01)
This is how the center of NGC 1365 works: https://asterisk.apod.com/download/file.php?id=49106&mode=view Optical image of NGC 1365 from the Dark Energy Survey (left). Credit: Schinnerer et al. 2023 Ann so a bar in a barred galaxy is a pair of wide and slightly curved jets flowing to the ring-sh...
- Thu Feb 01, 2024 3:19 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Pleiades: Seven Dusty Sisters (2024 Jan 29)
- Replies: 23
- Views: 4300
Re: APOD: The Pleiades: Seven Dusty Sisters (2024 Jan 29)
Under clear skies, the sky is almost the same blue anywhere, opposite the Sun or right next to the Sun. The color of the Sun itself (and therefore the direct light it casts) is filtered towards yellow/orange/red by the scattering away of blue. the sky of Sunset at Cerro Armazones, 360° Panorama htt...
- Thu Feb 01, 2024 1:23 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: NGC 1365: Majestic Island Universe (2024 Feb 01)
- Replies: 19
- Views: 536002
Re: APOD: NGC 1365: Majestic Island Universe (2024 Feb 01)
This is how the center of NGC 1365 works: https://asterisk.apod.com/download/file.php?id=49106&mode=view Optical image of NGC 1365 from the Dark Energy Survey (left). Credit: Schinnerer et al. 2023 Ann so a bar in a barred galaxy is a pair of wide and slightly curved jets flowing to the ring-sh...
- Thu Feb 01, 2024 12:48 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Camera Orion Rising (2024 Jan 31)
- Replies: 10
- Views: 14623
Re: APOD: Camera Orion Rising (2024 Jan 31)
I wonder if this deep sky APOD contains any coincidences with the constellation art of old.
- Thu Feb 01, 2024 11:56 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Pleiades: Seven Dusty Sisters (2024 Jan 29)
- Replies: 23
- Views: 4300
Re: APOD: The Pleiades: Seven Dusty Sisters (2024 Jan 29)
Interstellar dust is "brown" (low saturation red/orange) because of the nature of the silicates and carbonates that make it up. I think the scatter is primarily Rayleigh scattering off of very tiny particles and gas molecules, in which case the forward and back scatter are symmetric, and ...
- Tue Jan 30, 2024 6:33 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Pleiades: Seven Dusty Sisters (2024 Jan 29)
- Replies: 23
- Views: 4300
Re: APOD: The Pleiades: Seven Dusty Sisters (2024 Jan 29)
Interstellar dust is "brown" (low saturation red/orange) because of the nature of the silicates and carbonates that make it up. I think the scatter is primarily Rayleigh scattering off of very tiny particles and gas molecules, in which case the forward and back scatter are symmetric, and ...
- Mon Jan 29, 2024 3:02 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Pleiades: Seven Dusty Sisters (2024 Jan 29)
- Replies: 23
- Views: 4300
Re: APOD: The Pleiades: Seven Dusty Sisters (2024 Jan 29)
https://images.fineartamerica.com/images-medium-large-5/a-wide-field-view-over-the-pleiades-roberto-colombari.jpg https://apod.nasa.gov/apod/image/0911/california7_andreo.jpg Ann I made an attemt to subtract the general galactic illumination on the dust Wide field Pleiades with light brown dust bun...
- Sun Jan 28, 2024 10:28 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Pluto in True Color (2024 Jan 28)
- Replies: 6
- Views: 2297
Re: APOD: Pluto in True Color (2024 Jan 28)
what the Great Red Spot of Jupiter was in fact slightly yellowish light gray?
- Mon Jan 22, 2024 6:09 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Shadows of Mountain and Moon (2024 Jan 22)
- Replies: 8
- Views: 2576
Re: APOD: Shadows of Mountain and Moon (2024 Jan 22)
just imagine the huge plane through the two parallel terminator lines!
Still Saturn's rings are even larger
Still Saturn's rings are even larger
- Mon Jan 08, 2024 6:15 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Phases of Venus (2024 Jan 08)
- Replies: 9
- Views: 22108
Re: APOD: The Phases of Venus (2024 Jan 08)
I wonder if the 3d and 4th crescents are shown in the wrong order
- Thu Dec 28, 2023 9:29 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Rainbow Aurora over Icelandic Waterfall (2023 Dec 27)
- Replies: 13
- Views: 5151
Re: APOD: Rainbow Aurora over Icelandic Waterfall (2023 Dec 27)
https://i.ytimg.com/vi/6dtzfW6FO8I/maxresdefault.jpg Ann I was intrigued with colour-coding here and googled. it's heliocentric distance: blue=closer, red=distant Orphan stream (colour coded red to orange) is 20 kly long so I guess it is outside the disk. I wonder if any blue-coded streams are insi...
- Thu Dec 28, 2023 8:56 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Rainbow Aurora over Icelandic Waterfall (2023 Dec 27)
- Replies: 13
- Views: 5151
Re: APOD: Rainbow Aurora over Icelandic Waterfall (2023 Dec 27)
https://www.esa.int/var/esa/storage/images/esa_multimedia/images/2018/04/gaia_s_sky_in_colour2/17475368-10-eng-GB/Gaia_s_sky_in_colour_pillars.jpg One more thing. We are used to seeing pictures of spiral galaxies where the (typically blue) arms have been made to look brighter than they are, compare...
- Wed Dec 27, 2023 8:03 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Rainbow Aurora over Icelandic Waterfall (2023 Dec 27)
- Replies: 13
- Views: 5151
Re: APOD: Rainbow Aurora over Icelandic Waterfall (2023 Dec 27)
- Wed Dec 27, 2023 3:04 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Rainbow Aurora over Icelandic Waterfall (2023 Dec 27)
- Replies: 13
- Views: 5151
Re: APOD: Rainbow Aurora over Icelandic Waterfall (2023 Dec 27)
here are my 5 layman's constellations
- Tue Dec 26, 2023 9:36 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
- Replies: 37
- Views: 13304
Re: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
I'm assuming that the imager's stated time of 18:52 is his local time, CST (or 17:52 UT), which is what I'm basing my calculation on. FWIW, the mountain is 70 km from the basilica, and about 3000 m higher. So there's no way at all the Moon could be 9° above the horizon. 3 km / 70 km = tg 2.5° ok, t...
- Mon Dec 25, 2023 11:13 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
- Replies: 37
- Views: 13304
Re: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
after subtracting the blue shine (rgb = 45 64 91) there are some stars in the sky, probably not visible without a telescope Cathedral, Mountain, Moon-black.jpg I think the near total absence of stars is largely explained because we are looking through hundreds of kilometers of atmosphere within jus...
- Mon Dec 25, 2023 11:00 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
- Replies: 37
- Views: 13304
Re: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
after subtracting the blue shine (rgb = 45 64 91) there are some stars in the sky, probably not visible without a telescope
- Mon Dec 25, 2023 10:01 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
- Replies: 37
- Views: 13304
Re: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
Double checked the ephemeris. Taking the location as Turin (because it's in the list, and only a few miles away), 15 Dec 2023, 18:52 local, I get the Moon at 2° above the horizon, the Sun at 21° below the horizon, Moon at 10% waxing. I am feeling lost. Is Stellarium so unprecise? Is using "loc...
- Mon Dec 25, 2023 9:18 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
- Replies: 37
- Views: 13304
Re: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
This is a 10% Moon that is 2° above the horizon. The Sun is 21° below the horizon, so just out of astronomical twilight and it should not be contributing significant light. I would be curious to know the technical details of the image. I don't think it could be achieved without some kind of HDR pro...
- Mon Dec 25, 2023 8:29 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
- Replies: 37
- Views: 13304
Re: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
This is a 10% Moon that is 2° above the horizon. The Sun is 21° below the horizon, so just out of astronomical twilight and it should not be contributing significant light. I would be curious to know the technical details of the image. I don't think it could be achieved without some kind of HDR pro...
- Mon Dec 25, 2023 8:07 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
- Replies: 37
- Views: 13304
Re: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
looked up 1) date and time = December 15, 2023 at 18:52 pm 2) stellarium Cathedral, Mountain, Moon..jpg Cathedral, Mountain, Moon-..jpg https://asterisk.apod.com/download/file.php?id=48994&t=1 Moon is 9° above (+09°01'15.1") and Phase=9%, Sun is 11° below (-10°55'12.6") Twilight it is
- Mon Dec 25, 2023 5:38 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
- Replies: 37
- Views: 13304
Re: APOD: Cathedral, Mountain, Moon (2023 Dec 25)
Distance. Monviso is far enough from the camera that the air scatter (chiaroscuro) between them is saturated, or nearly so. (playing the kid who could have asked the kid's question) I take it you assume that the light scattered is not coming from Moon (and this must be so seeing the shine is blue r...