APOD: Gaia's Milky Way (2018 Apr 27)

Comments and questions about the APOD on the main view screen.
User avatar
neufer
Vacationer at Tralfamadore
Posts: 14957
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: Gaia's Milky Way (2018 Apr 27)

Post by neufer » Sun Apr 29, 2018 4:57 pm

Ann wrote:
Sun Apr 29, 2018 5:16 am

So the way to understand Gaia's ability to detect M33 and its inability(?) to detect M31 is to realize that Gaia can't photograph a galaxy "all at once", but only "star by star" or "discrete light source by discrete light source". And M31 has too few sufficiently bright discrete light sources in order to show up clearly in Gaia's picture.
https://en.wikipedia.org/wiki/Triangulum_Galaxy wrote:
<<Star formation is taking place at a rate that is strongly correlated with the local gas density, and the rate per unit area is higher than in the neighboring Andromeda Galaxy. (The rate of star formation is about 3.40 Gyr−1 pc−2 in the Triangulum galaxy, compared to 0.74 in Andromeda.)>>
Art Neuendorffer

User avatar
neufer
Vacationer at Tralfamadore
Posts: 14957
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: Gaia's Milky Way (2018 Apr 27)

Post by neufer » Thu May 03, 2018 2:59 am

Click to play embedded YouTube video.
Art Neuendorffer