Starship Asterisk*

Ann wrote:Hooray!!! Adam Block has posted a new galaxy picture - of lovely galaxy NGC 2276 and its elliptical "friend" NGC 2300!!!

Ann

http://heritage.stsci.edu/2014/04/caption.html wrote:
This image is being used to support a citizen science project titled STAR DATE: M83. The primary goal is to estimate ages for approximately 3,000 star clusters. Amateur scientists will use the presence or absence of the pink hydrogen emission, the sharpness of the individual stars, and the color of the clusters to estimate ages. Participants will measure the sizes of the star clusters and any associated emission nebulae. Finally, the citizen scientists will "explore" the image, identifying a variety of objects ranging from background galaxies to supernova remnants to foreground stars.

STAR DATE: M83 is a joint collaborative effort between the Space Telescope Science Institute and Zooniverse, creators of several citizen science projects including Galaxy Zoo, Planet Hunters, and the Andromeda Project (go to www.zooniverse.org to see the full list). The M83 project is scheduled to launch on Monday, January 13, 2014. People interested in exploring this remarkable image in more detail, and in directly participating in a science project, can visit http://www.projectstardate.org .

Ann wrote:

starsurfer wrote:NGC 2633-4
http://www.astrobin.com/68136/
Copyright: Samuel Díaz Lopez and Salvatore Iovene

f546225df01771c70e7e5b0f0f71d543.1824x0_q100.jpg

NGC 2633 is the barred spiral and NGC 2634 is the shell elliptical galaxy. Its shells were discovered in 2000 but for some reason a paper was never published. NGC 2633 is also known as Arp 80 but NGC 2634 certainly qualifies as a peculiar galaxy and should have been included in the Arp Atlas but its outer shells probably wouldn't have been visible at the time Halton Arp was compiling the atlas. There are other shell elliptical galaxies in the Arp Atlas such as NGC 474, NGC 507, IC 51 and IC 1575, which appear under the category of "galaxies with concentric rings". IC 51 (Arp 230) is an amazing example, a comparison of the original plate and a HST image.

Shells around many ellipticals were discovered after new techniques in photographic enhancement such as unsharp masking were pioneered by David Malin who made one of the first recognised discoveries of a shell elliptical in 1979, this was the galaxy M89. Afterwards, many more were found and a catalogue was published by David Malin and David Carter in 1983.

In the decades that have followed, shell ellipticals have been studied by many astronomers with observatories such as the HST and GALEX and continue to receive much attention now and will continue to do so in the foreseeable future. A major topic of interest in studies of galactic evolution is the mass assembly of galaxies. There are large-scale projects that aim to detect faint structures around both spiral galaxies and elliptical galaxies. These features represent the remnants of minor merger interactions and signatures of past collisions. It is widely believed that the shells in shell ellipticals are the product of mergers between galaxies. Also shell ellipticals are beginning to receive more attention from amateur astrophotographers!

That's so interesting, and what a great picture, starsurfer (and Samuel Díaz Lopez and Salvatore Iovene)!

Ann

starsurfer wrote:NGC 2633-4
http://www.astrobin.com/68136/
Copyright: Samuel Díaz Lopez and Salvatore Iovene

f546225df01771c70e7e5b0f0f71d543.1824x0_q100.jpg

NGC 2633 is the barred spiral and NGC 2634 is the shell elliptical galaxy. Its shells were discovered in 2000 but for some reason a paper was never published. NGC 2633 is also known as Arp 80 but NGC 2634 certainly qualifies as a peculiar galaxy and should have been included in the Arp Atlas but its outer shells probably wouldn't have been visible at the time Halton Arp was compiling the atlas. There are other shell elliptical galaxies in the Arp Atlas such as NGC 474, NGC 507, IC 51 and IC 1575, which appear under the category of "galaxies with concentric rings". IC 51 (Arp 230) is an amazing example, a comparison of the original plate and a HST image.

Shells around many ellipticals were discovered after new techniques in photographic enhancement such as unsharp masking were pioneered by David Malin who made one of the first recognised discoveries of a shell elliptical in 1979, this was the galaxy M89. Afterwards, many more were found and a catalogue was published by David Malin and David Carter in 1983.

In the decades that have followed, shell ellipticals have been studied by many astronomers with observatories such as the HST and GALEX and continue to receive much attention now and will continue to do so in the foreseeable future. A major topic of interest in studies of galactic evolution is the mass assembly of galaxies. There are large-scale projects that aim to detect faint structures around both spiral galaxies and elliptical galaxies. These features represent the remnants of minor merger interactions and signatures of past collisions. It is widely believed that the shells in shell ellipticals are the product of mergers between galaxies. Also shell ellipticals are beginning to receive more attention from amateur astrophotographers!