Search found 7 matches

by Newtownian
Thu Jan 20, 2022 9:24 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: M31: The Andromeda Galaxy (2022 Jan 19)
Replies: 12
Views: 4170

Re: APOD: M31: The Andromeda Galaxy (2022 Jan 19)

Most high resolution deep field galaxy images comparable to this show up a menagerie of more distant galaxies. But I could only find a few few dim distant spiral candidates. Have these more distant been editted out? Is this an artefact of Andromed covering such an expanse? Or are we looking in the d...
by Newtownian
Mon Nov 29, 2021 6:56 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A High Cliff on Comet... (2021 Nov 28)
Replies: 13
Views: 3868

Re: APOD: A High Cliff on Comet... (2021 Nov 28)

Will the outgassing increasingly make the comet spin and as it shrinks into rubble help it take on a spherical shape? Related to this is there any particular reason why we have seen at least two of these rubble residues take on a near Octahedral shape instead of one of the other polyhedrons? Might w...
by Newtownian
Sun Nov 14, 2021 6:07 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: How to Identify that Light in the Sky (2021 Nov 14)
Replies: 26
Views: 12251

Re: APOD: How to Identify that Light in the Sky (2021 Nov 14)

Probably been said before but this taxonomy manages to omit most of the really interesting naked eye fuzzy objects, depending on sky darkness - 4 galaxies (LMC, SMC, Andromeda, Triangulum), 7 (caldwell) + 10 (messier) fuzzy globular clusters brighter than magnitude 7, a number of fuzzy naked eye neb...
by Newtownian
Fri Jun 30, 2017 4:58 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Composite Messier 20 and 21 (2017 Jun 28)
Replies: 34
Views: 6138

Re: APOD: Composite Messier 20 and 21 (2017 Jun 28)

It may not be that the oblateness of many stars is sufficient to be measured. But if a useful relationship could be derived then spectra from space telescopes (Gaia?) might provide a means of estimating the oblateness of fast spinning stars (would Gaia be able to provide measurements of oblateness ...
by Newtownian
Thu Jun 29, 2017 12:40 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Composite Messier 20 and 21 (2017 Jun 28)
Replies: 34
Views: 6138

Re: APOD: Composite Messier 20 and 21 (2017 Jun 28)

"I think it probably wouldn't work too well because in fact, stars are not very good blackbodies. That's because the photons they emit are produced over a range of their outer regions, and there is a temperature gradient across that emission range. So their spectrum already consists of a super...
by Newtownian
Wed Jun 28, 2017 10:00 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Composite Messier 20 and 21 (2017 Jun 28)
Replies: 34
Views: 6138

Re: APOD: Composite Messier 20 and 21 (2017 Jun 28)

"I think it probably wouldn't work too well because in fact, stars are not very good blackbodies. That's because the photons they emit are produced over a range of their outer regions, and there is a temperature gradient across that emission range. So their spectrum already consists of a superp...
by Newtownian
Wed Jun 28, 2017 1:12 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Composite Messier 20 and 21 (2017 Jun 28)
Replies: 34
Views: 6138

Re: APOD: Composite Messier 20 and 21 (2017 Jun 28)

The link from M21 goes to this site https://www.universetoday.com/31935/messier-21/ which discusses rapidly spinning Be stars of which Achernar is an extreme example. As a result of this spin the star is reportedly greatly flattened and as a result its surface varies in temperature. I wondered how t...