NGC 4882
 NGC 4882 u góry po lewej, duża galaktyka poniżej niej to NGC 4889 (HST) | |
| Odkrywca | |
|---|---|
| Data odkrycia | 6 kwietnia 1864 |
| Dane obserwacyjne (J2000) | |
| Gwiazdozbiór | |
| Typ | eliptyczna (E) |
| Rektascensja | 13h 00m 04,6s |
| Deklinacja | +27° 59′ 11″ |
| Przesunięcie ku czerwieni | 0,02137[1] |
| Jasność obserwowana | 13,9m |
| Rozmiary kątowe | 0,6' × 0,6' |
| Alternatywne oznaczenia | |
| NGC 4886, MCG 5-31-76, ZWG 160.239, DRCG 27-151, PGC 44698 | |
NGC 4882 (również NGC 4886 lub PGC 44698) – galaktyka eliptyczna (E), znajdująca się w gwiazdozbiorze Warkocza Bereniki.
Odkrył ją Heinrich Louis d’Arrest 6 kwietnia 1864 roku. Obserwował ją też 22 kwietnia 1865 roku, lecz tym razem obliczył jej pozycję mniej dokładnie i nie zorientował się, że to ten sam obiekt, który obserwował rok wcześniej[2]. John Dreyer skatalogował obie obserwacje d’Arresta jako, odpowiednio, NGC 4886 i NGC 4882[3].
Zobacz też
Przypisy
- ↑ NGC 4882 w bazie SIMBAD (ang.)
- ↑ Harold G. Corwin, Jr.: NGC 4882 = NGC 4886. [w:] Notes on the NGC objects, particularly those missing, misidentified, or otherwise unusual [on-line]. 2015-04-24. [dostęp 2015-05-25]. (ang.).
- ↑ Courtney Seligman: NGC 4882. [w:] Celestial Atlas [on-line]. [dostęp 2015-05-25]. (ang.).
Linki zewnętrzne
- NGC 4882 w serwisie SEDS.org (Revised NGC and IC Catalog) (ang.)
- NGC 4882 w bazie SIMBAD (ang.)
- NGC 4882 w NASA/IPAC Extragalactic Database (ang.)
Media użyte na tej stronie
Autor: Judy Schmidt from Fresh Meadows, NY, USA, Licencja: CC BY 2.0
A dominant member of the Coma Cluster, remarkable elliptical shell galaxy NGC 4889 looms large over its domain. Within the cluster, only NGC 4874 (not shown) is brighter, and only just barely.
The faintly visible shells of the galaxy are evidence that the monstrous galaxy recently merged with a smaller galaxy.
Other details to notice include smaller and/or more distant elliptical galaxies, some of which are ghostly and faint. I have seen them called them fluffy galaxies in this recent press release. The nature of these ultra-diffuse galaxies and specifically how they manage to form as they do is still a matter of speculation.
Very few Milky Way stars are visible within the field. As usual, the ones with four spikes are most likely foreground stars. The hundreds of tiny, fainter point-like objects are globular clusters, many of which are likely orbiting NGC 4889.
Do you think that maybe some background galaxies show a curious alignment? You might not be imagining it. It's possible that some weak gravitational lensing is going on. Weak gravitational lensing is detectable by taking measurements of all the background galaxies and seeing if they all seem a bit squished in a certain direction.
One final curiosity that I would like to note about NGC 4889: If you measure the brightness of the center of its nucleus, it is actually not as bright as NGC 4886, which is the smaller elliptical galaxy just above it in this image (that one skinny galaxy is kind of pointing toward it). The way some elliptical galaxies have diffuse cores while others have very sharp ones is something that perplexes me. It seems that even though NGC 4889 is much larger than NGC 4886, its nucleus is notably less dense than NGC 4886's.
Red: ACS / WFC F814W (jb2i02020_drc) Green: Pseudo Blue: ACS / WFC F475W (jb2i02010_drc & jb2i03010_drc)
North is NOT up. It is 43.6° counter-clockwise from up.