Search found 26 matches
- Sun Jul 10, 2022 11:13 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: In the Center of the Cat's Eye Nebula (2022 Jul 10)
- Replies: 41
- Views: 21127
Re: APOD: In the Center of the Cat's Eye Nebula (2022 Jul 10)
Doesn't require any experience. Everyone I have shown these two can see the the colour without any prompting. Even people who have never looked through a scope in their life before.
- Sun Jul 10, 2022 10:43 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: In the Center of the Cat's Eye Nebula (2022 Jul 10)
- Replies: 41
- Views: 21127
Re: APOD: In the Center of the Cat's Eye Nebula (2022 Jul 10)
I have never liked planetary nebulas much. The reason is precisely because I wasn't able, for the longest time, to figure out what color they really are, or why. (Now I think I know - they glow at 501 nm and 656 nm.) The wild and strange colors in Hubble images of planetaries made me go off planeta...
- Tue Oct 15, 2019 11:25 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Galaxy Above (2019 Oct 15)
- Replies: 14
- Views: 10028
Re: APOD: The Galaxy Above (2019 Oct 15)
Congratulation, beautiful picture! I would be interested to know why two images had to be overlaid? Why it was not possible at one time? The usual reason is that the sky is imaged using a long exposure with the camera on an equatorial tracking mount. This stops the stars trailing but blurs the fore...
- Fri Jun 21, 2019 12:42 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A View Toward M106 (2019 Jun 20)
- Replies: 12
- Views: 5181
Re: APOD: A View Toward M106 (2019 Jun 20)
Sorry if I've already asked this in the past. Whenever I look at such photos, I always wonder, which one of the bright objects (of various sizes, shapes and colors) we see are stars and which ones are galaxies. There are some photos wherein every object (almost every) is a galaxy. But, some have a ...
- Fri Jun 14, 2019 2:10 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Colors and Magnitudes of M13 (2019 Jun 13)
- Replies: 14
- Views: 7341
Re: APOD: The Colors and Magnitudes of M13 (2019 Jun 13)
A question, SVP: Lovely photo, but how many of the “several hundreds of thousands” of stars can be individually analyzed and converted into data points in the H-R diagram? Surely not even one of several hundreds of thousands. Sooo.... how can they be sure they have a representative sample? Couldn’t...
- Thu Apr 11, 2019 11:12 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: First Horizon-Scale Image of a Black... (2019 Apr 11)
- Replies: 128
- Views: 49102
Re: APOD: First Horizon-Scale Image of a Black... (2019 Apr 11)
As mentioned earlier in the thread, they are using a wavelength of 1.3mm. This is at the short end of the microwave spectrum, which would be strongly attenuated by clouds and rain.
- Thu Apr 11, 2019 5:30 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: First Horizon-Scale Image of a Black... (2019 Apr 11)
- Replies: 128
- Views: 49102
Re: APOD: First Horizon-Scale Image of a Black... (2019 Apr 11)
Thats awesome. But would it be being difficult to ask how it is that radio telescopes can 'see' or resolve such stuff, at the minute angles and immense distances that this is being observed at ? Resolution is proportional to wavelength divided by aperture. The answer is that they have a large effec...
- Wed Oct 31, 2018 10:33 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: R Leporis: A Vampire's Star (2018 Oct 31)
- Replies: 15
- Views: 3343
Re: APOD: R Leporis: A Vampire's Star (2018 Oct 31)
The carbon star DY Crucis is interesting to observe in contrast to the adjacent 1st magnitude Beta Crucis (Mimosa). The two are separated by only a bit over two arc minutes. There is a big difference in brightness but that seems to enhance the deep red colour of DY Crucis.
- Wed Sep 12, 2018 4:45 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Lunations (2018 Sep 12)
- Replies: 27
- Views: 7447
Re: APOD: Lunations (2018 Sep 12)
Nice animation. Northern hemisphere centric though ![Wink ;)](./images/smilies/icon_wink.gif)
![Wink ;)](./images/smilies/icon_wink.gif)
- Wed May 16, 2018 8:08 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Rotation of the Large Magellanic Cloud (2018 May 16)
- Replies: 39
- Views: 29633
Re: APOD: Rotation of the Large Magellanic Cloud (2018 May 16)
I heard that Gaia's mission is to take up to 70 snapshots of its targets over 5 years [Wikipedia], and the elapsed time since Gaia's launch is 4 years, 4 months, and 27 days, I'd say the time period is around 4 years and 4 months. (Just my unofficial guess.) DR2 covers the first 22 months of data c...
- Wed May 16, 2018 10:55 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Rotation of the Large Magellanic Cloud (2018 May 16)
- Replies: 39
- Views: 29633
Re: APOD: Rotation of the Large Magellanic Cloud (2018 May 16)
ata Which time span is displayed or extrapolated in this picture? I heard that Gaia's mission is to take up to 70 snapshots of its targets over 5 years [Wikipedia], and the elapsed time since Gaia's launch is 4 years, 4 months, and 27 days, I'd say the time period is around 4 years and 4 months. (J...
- Wed May 16, 2018 8:22 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Rotation of the Large Magellanic Cloud (2018 May 16)
- Replies: 39
- Views: 29633
Re: APOD: Rotation of the Large Magellanic Cloud (2018 May 16)
Some evidence:Adriano wrote: ↑Wed May 16, 2018 5:54 am Superb picture. Is there a black hole at the centre of LMC?
https://arxiv.org/abs/1804.10197
- Mon Mar 26, 2018 3:56 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Announcing Nova Carinae 2018 (2018 Mar 25)
- Replies: 10
- Views: 50613
Re: APOD: Announcing Nova Carinae 2018 (2018 Mar 25)
When I first saw today's Announcement; I thought old Eta might have finally blown her self up! Imagine the disappointment! I guess not as much disappointment as when a certain Professor recently announced the discovery of a > 1st magnitude transient in Sagittarius which turned out to be Mars :lol2:
- Tue Dec 12, 2017 10:56 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Highlights of the Winter Sky (2017 Dec 12)
- Replies: 10
- Views: 8408
Re: APOD: Highlights of the Winter Sky (2017 Dec 12)
It looks like the Southern hemisphere viewpoint but Gemini is out of place? Should be Taurus, Orion, Gemini then Cancer when looking at the Southern hemisphere Northern Sky going from from West to East
- Fri Nov 03, 2017 9:58 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A/2017 U1: An Interstellar Visitor (2017 Nov 03)
- Replies: 42
- Views: 13201
Re: APOD: A/2017 U1: An Interstellar Visitor (2017 Nov 03)
I have seen the albedo estimated to be around ten percent which isn't a lot different to the Moon. Quite dark compared to icy bodies if the estimates are accurate. I wouldn't make any guess at origin since it's speed relative to the Sun (when the asteroid was well out in interstellar space) is quite...
- Wed Jul 12, 2017 1:05 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Star Cluster Omega Centauri in HDR (2017 Jul 11)
- Replies: 41
- Views: 8782
Re: Some technical details on the image
A deep look at Omega Centauri ( NGC 5139 ) Capture: 9 sets of sub-images with exposure duration for each set doubling ( 1s to 240s ) all at ISO800. Processing:. Calibration: master bias, master flat and no darks. Integration in 9 sets. HDR combination. Pixinsight May 2017 Hi Mike, Great image. I'm ...
- Thu Feb 23, 2017 7:26 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Seven Worlds for TRAPPIST-1 (2017 Feb 23)
- Replies: 44
- Views: 8149
Re: APOD: Seven Worlds for TRAPPIST-1 (2017 Feb 23)
Anyone know the orbital period of each planet? I saw a range from 1.5 to 12 days mentioned but not the individual period of each planet. I'm wondering how stable the arrangement is.
- Tue Feb 21, 2017 11:54 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Black Sun and Inverted Starfield (2017 Feb 19)
- Replies: 13
- Views: 3622
Re: APOD: Black Sun and Inverted Starfield (2017 Feb 19)
"Some cruel people also suggest that astronomers' dandruff falling on a positive image could be mistaken for stars!"
Makes me wonder if some star catalogues have any dandruff listed in them and what the spectral type would be.
Makes me wonder if some star catalogues have any dandruff listed in them and what the spectral type would be.
- Wed Oct 19, 2016 11:45 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M45: The Pleiades Star Cluster (2016 Oct 19)
- Replies: 11
- Views: 3015
Re: APOD: M45: The Pleiades Star Cluster (2016 Oct 19)
The distance to the cluster is (maybe was) a small controversy. Radio telescope VLBI and a number of other methods measured the distance at around 135 parsecs, whereas the ESA Hipparcos satellite gave a result around 118 parsecs, well outside the margin of error. The first data release from the ESA ...
- Thu Sep 15, 2016 8:46 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Retrograde Mars and Saturn (2016 Sep 15)
- Replies: 10
- Views: 5489
Re: APOD: Retrograde Mars and Saturn (2016 Sep 15)
It's interesting that Aristarchus and other Greeks of the time had proposed the heliocentric view. Even the Roman's Pliny and Seneca wrote that the retrograde motion of the planets was merely "apparent". That suggests that the heliocentric model was more widely accepted than is often state...
- Tue Jun 28, 2016 1:18 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Jupiter's Clouds from New Horizons (2016 Jun 26)
- Replies: 33
- Views: 10649
Re: APOD: Jupiter's Clouds from New Horizons (2016 Jun 26)
On Pluto the Sun is between 150 and 450 times as bright as the full Moon as seen from Earth. The range of brightness relates to Pluto's elliptical orbit. Even when Pluto is at aphelion, you would have no trouble seeing stuff on Pluto's day side.
- Fri Apr 29, 2016 5:17 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Dust Angel Nebula (2016 Apr 28)
- Replies: 18
- Views: 3819
Re: APOD: A Dust Angel Nebula (2016 Apr 28)
You mean like the perfect circle traced out by stars in the top 1/5th of the picture, immediately below the word April? Yes: even if the stars seem to say Vote Trump, it is random. Every now and then I'll spot a straight line of stars in an image, something like 7 in a row. Enough for me to stop an...
- Thu Apr 28, 2016 9:36 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Omega Centauri: The Brightest Star... (2016 Apr 27)
- Replies: 39
- Views: 4437
Re: APOD: Omega Centauri: The Brightest Star... (2016 Apr 27)
The Gaia data will also improve many of the other methods. For example, they will get accurate parallax measurements of a considerable number of Cepheid variables allowing improved calibration of that method.
- Thu Apr 28, 2016 3:31 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Omega Centauri: The Brightest Star... (2016 Apr 27)
- Replies: 39
- Views: 4437
Re: APOD: Omega Centauri: The Brightest Star... (2016 Apr 27)
That's really interesting to know. Going forward I will need to look a little more critically at the distances published in Astronomy related articles. It would be nice if quoted distances were accompanied in brackets by some form of abbreviation which would define either the measurement technique ...
- Wed Jan 27, 2016 2:24 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Candidate for the Biggest Boom Yet... (2016 Jan 26)
- Replies: 54
- Views: 9047
Re: APOD: A Candidate for the Biggest Boom Yet... (2016 Jan 26)
I wonder if any associated GRB was detected?