Search found 1117 matches
- Sat Jul 02, 2022 9:58 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Solargraphic Analemmas (2022 Jul 02)
- Replies: 15
- Views: 3904
Re: APOD: Solargraphic Analemmas (2022 Jul 02)
Analemma1_1024c.jpg I thought they were made by putting film in a tin can with a pin hole opening and placing it in a dark spot and facing an opening to the horizon! ... That's what he used, but he added an electronic shutter to "snap" the images. The thermal-sensitive paper essentially c...
- Thu Jun 30, 2022 2:57 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Solar System Family Portrait (2022 Jun 29)
- Replies: 21
- Views: 7874
Re: APOD: Solar System Family Portrait (2022 Jun 29)
Ah. Yeah, I missed that. Not sure why having them all on one side is at all interesting, but there you go.They're not all on the same side in December. Not that anybody could tell that by eye. _ Screenshot 2022-06-29 152834.png So that pic seems to show them all south of the ecliptic, right? Is tha...
- Wed Jun 22, 2022 4:21 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Supernova Remnant: The Veil Nebula (2022 Jun 22)
- Replies: 7
- Views: 3781
Re: APOD: Supernova Remnant: The Veil Nebula (2022 Jun 22)
Wow, never have seen the Veil quite like that before. Very mesmerizing - I immersed myself so deep into the dark, secretive face / faces behind the electrified head of hair that I never realized there were no stars until I read the description.
- Wed Jun 22, 2022 4:11 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Analemma over Taipei (2022 Jun 21)
- Replies: 24
- Views: 5242
Re: APOD: Analemma over Taipei (2022 Jun 21)
In 2021, I spent a whole year in Taipei recording the position of the sun at 7:30 am and 4:30 pm. In the northern hemisphere, the summer solstice of the sun analemma in the morning is at upper left, and the winter solstice at lower right. As for the sun analemma in the afternoon, the tilt direction...
- Wed Jun 22, 2022 2:18 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Analemma over Taipei (2022 Jun 21)
- Replies: 24
- Views: 5242
Re: APOD: Analemma over Taipei (2022 Jun 21)
In 2021, I spent a whole year in Taipei recording the position of the sun at 7:30 am and 4:30 pm. In the northern hemisphere, the summer solstice of the sun analemma in the morning is at upper left, and the winter solstice at lower right. As for the sun analemma in the afternoon, the tilt direction...
- Tue Jun 21, 2022 7:04 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Analemma over Taipei (2022 Jun 21)
- Replies: 24
- Views: 5242
Re: APOD: Analemma over Taipei (2022 Jun 21)
I'm a bit confused as to why the two equinox lines don't coincide. Shouldn't they? I had the same question. I could imagine some slight misalignment, but they're not close at all. No, the equinox points do not coincide. Earth's orbital eccentricity creates the asymmetric figure 8 as pointed up earl...
- Tue Jun 21, 2022 4:49 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Analemma over Taipei (2022 Jun 21)
- Replies: 24
- Views: 5242
Re: APOD: Analemma over Taipei (2022 Jun 21)
I'm a bit confused as to why the two equinox lines don't coincide. Shouldn't they? I had the same question. I could imagine some slight misalignment, but they're not close at all. No, the equinox points do not coincide. Earth's orbital eccentricity creates the asymmetric figure 8 as pointed up earl...
- Fri Jun 17, 2022 3:36 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Strawberry Supermoon from China (2022 Jun 16)
- Replies: 12
- Views: 2881
Re: APOD: Strawberry Supermoon from China (2022 Jun 16)
OK, De28te, I bow to your horticultural knowledge. But which cultures cultivate strawberries? Although the genus is distributed world wide, the 'garden' strawberry is an 18th century hybrid from France (according to Wiki) and previous references were to the woodland strawberry, that has tiny fruit ...
- Sun Jun 12, 2022 2:36 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Road and the Milky Way (2022 Jun 11)
- Replies: 9
- Views: 2103
Re: APOD: The Road and the Milky Way (2022 Jun 11)
Man, my first search for "Dark Sky Alqueva reserve" in Bing put me about 1000 miles to the west off the coast of Portugal: https://www.bing.com/maps?q=Dark+Sky+Alqueva+reserve&FORM=INCOH2&PC=1VIV&PTAG=ICO-c9d0fc87 Oddly though, Bing still had the correct website address: https...
- Sat Jun 11, 2022 5:09 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Road and the Milky Way (2022 Jun 11)
- Replies: 9
- Views: 2103
Re: APOD: The Road and the Milky Way (2022 Jun 11)
Man, my first search for "Dark Sky Alqueva reserve" in Bing put me about 1000 miles to the west off the coast of Portugal: https://www.bing.com/maps?q=Dark+Sky+Alqueva+reserve&FORM=INCOH2&PC=1VIV&PTAG=ICO-c9d0fc87 Oddly though, Bing still had the correct website address: https...
- Sat Jun 11, 2022 4:12 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Road and the Milky Way (2022 Jun 11)
- Replies: 9
- Views: 2103
Re: APOD: The Road and the Milky Way (2022 Jun 11)
Vega is the "star" attraction here.
- Sun Jun 05, 2022 5:23 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A 10,000 Kilometer Galactic Bridge (2022 Jun 03)
- Replies: 13
- Views: 2498
Re: APOD: A 10,000 Kilometer Galactic Bridge (2022 Jun 03)
By the numbers, compared to today's visible ~205° MW swath, the 2020 APOD displays about 265°, or about 30% larger,
- Fri Jun 03, 2022 4:21 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Tau Herculids Meteors over Kitt Peak... (2022 Jun 01)
- Replies: 11
- Views: 5970
Re: APOD: Tau Herculids Meteors over Kitt Peak... (2022 Jun 01)
So, I think I found three of the unrelated meteors, but the fourth eludes me. My criterion was that they don't seem to follow the same radiant lines as the others. Also, many if not most of the others appear to end in a little ball of light. I assume that's the final dying flash? I think the 4th is...
- Thu Jun 02, 2022 4:18 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Tau Herculids Meteors over Kitt Peak... (2022 Jun 01)
- Replies: 11
- Views: 5970
Re: APOD: Tau Herculids Meteors over Kitt Peak... (2022 Jun 01)
So, I think I found three of the unrelated meteors, but the fourth eludes me. My criterion was that they don't seem to follow the same radiant lines as the others. Also, many if not most of the others appear to end in a little ball of light. I assume that's the final dying flash? I think the 4th is...
- Sun May 01, 2022 5:50 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: First Horizon-Scale Image of a Black... (2022 May 01)
- Replies: 11
- Views: 6014
Re: APOD: First Horizon-Scale Image of a Black... (2022 May 01)
Is an image of the central supermassive black hole of the Milky Way, Sgr A*, coming up? The people behind the portrait of the supermassive black hole in M87 have said that they will take a picture of Sgr A*, too. Perhaps it is coming soon? Go to this "Youtube short" by Dr Becky to hear he...
- Sun May 01, 2022 5:39 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: First Horizon-Scale Image of a Black... (2022 May 01)
- Replies: 11
- Views: 6014
Re: APOD: First Horizon-Scale Image of a Black... (2022 May 01)
... Pictured , the dark central region is not the event horizon, but rather the black hole's shadow -- the central region of emitting gas darkened by the central black hole's gravity. The size and shape of the shadow is determined by bright gas near the event horizon , by strong gravitational lensi...
- Wed Apr 27, 2022 4:50 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Moon Shadow on Jupiter (2022 Apr 27)
- Replies: 16
- Views: 7611
Re: APOD: Moon Shadow on Jupiter (2022 Apr 27)
https://apod.nasa.gov/apod/calendar/S_220427.jpg Moon Shadow on Jupiter Explanation: What is that large dark spot on Jupiter? It's the shadow of Io , one of Jupiter 's largest moons. ... Unlike on Earth, moon shadow s occur most days on Jupiter -- what's more unusual is that a spacecraft was close ...
- Sat Apr 16, 2022 2:40 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: CMB Dipole: Speeding Through the... (2022 Apr 03)
- Replies: 64
- Views: 28593
Re: APOD: CMB Dipole: Speeding Through the... (2022 Apr 03)
Thanks again, alter ego and chris. I'm still expecting that with the benefit of the JWST having a larger mirror and one better suited to infrared than anything we've been able to look through (from space) before, that it will detect serious galaxies, whose spectra indicate a larger redshift than ev...
- Sun Apr 10, 2022 11:54 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: CMB Dipole: Speeding Through the... (2022 Apr 03)
- Replies: 64
- Views: 28593
Re: APOD: CMB Dipole: Speeding Through the... (2022 Apr 03)
First, let me say that I appreciate these answers, from Chris and alter-ego. Also, the further comments that Ann and johnnydeep have added. An easy response to my post would have been something like: "No, you just need to take one or more courses that cover this, then you'd get it. Until then,...
- Sun Apr 10, 2022 11:52 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: CMB Dipole: Speeding Through the... (2022 Apr 03)
- Replies: 64
- Views: 28593
Re: APOD: CMB Dipole: Speeding Through the... (2022 Apr 03)
Maybe I get a little bit of what you are saying, alter-ego. If I get you correctly, the reason why the redshift increases so enormously the closer we get to the Big Bang is that the Universe underwent this incredible exponential growth spurt called inflation, and when that epoch was over the Univer...
- Sun Apr 10, 2022 4:40 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: CMB Dipole: Speeding Through the... (2022 Apr 03)
- Replies: 64
- Views: 28593
Re: APOD: CMB Dipole: Speeding Through the... (2022 Apr 03)
Ann wrote above: I think I "understand" - well, "expect" is a better word - the fact that the redshift will be much the same 7 billion years from now as it is today, because the redshift really increases "almost exponentially" the closer we get to the Big Bang, but fro...
- Sat Apr 09, 2022 2:48 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: CMB Dipole: Speeding Through the... (2022 Apr 03)
- Replies: 64
- Views: 28593
Re: APOD: CMB Dipole: Speeding Through the... (2022 Apr 03)
How would those photons be different if they had been in flight for 20 billion years? How could they have been in flight for greater than the age of the Universe? If the redshift led to that conclusion, we'd revise the age of the Universe. I think I'm questioning how rational the current interpreta...
- Sun Apr 03, 2022 3:23 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Nova Scotia Northern Lights (2022 Apr 02)
- Replies: 5
- Views: 2984
Re: APOD: Nova Scotia Northern Lights (2022 Apr 02)
The predicted geomagnetic storm was sparked as a coronal mass ejection,... "As" or "by"? And here's Cassiopeia: cassiopeia in aurora.JPG https://upload.wikimedia.org/wikipedia/commons/e/e7/Cassiopeia_IAU.svg "The predicted geomagnetic storm was sparked as a coronal mass eje...
- Fri Apr 01, 2022 4:43 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Venus and Mars: Passing in the Night (2022 Mar 29)
- Replies: 23
- Views: 43369
Re: APOD: Venus and Mars: Passing in the Night (2022 Mar 29)
Within the last few years, Art had taken a lengthy hiatus and I grew concerned. After a number of weeks, he reappeared to the forum. I was happy and relieved. This time I grew concerned again, and my heart sank after reading rwlott's post. I will forever remember the day Art passed - March 4 is my ...
- Thu Mar 31, 2022 3:48 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Venus and Mars: Passing in the Night (2022 Mar 29)
- Replies: 23
- Views: 43369
Re: APOD: Venus and Mars: Passing in the Night (2022 Mar 29)
Within the last few years, Art had taken a lengthy hiatus and I grew concerned. After a number of weeks, he reappeared to the forum. I was happy and relieved. This time I grew concerned again, and my heart sank after reading rwlott's post. I will forever remember the day Art passed - March 4 is my b...