NGC 4236
 Galaktyka NGC 4236 (Digitized Sky Survey) | |
| Odkrywca | |
|---|---|
| Data odkrycia | 6 kwietnia 1793 |
| Dane obserwacyjne (J2000) | |
| Gwiazdozbiór | |
| Typ | spiralna z poprzeczką, SBdm |
| Rektascensja | 12h 16m 41,75s |
| Deklinacja | +69° 28′ 09,7″ |
| Odległość | 11,7 mln ly |
| Przesunięcie ku czerwieni | –0,000003[1] |
| Jasność obserwowana | 10,7m |
| Rozmiary kątowe | 21,9' × 7,2' |
| Alternatywne oznaczenia | |
| PGC 39346, UGC 7306, IRAS 12143+6945, 2MASX J12164211+6927452 | |
NGC 4236 (również PGC 39346 lub UGC 7306) – galaktyka spiralna z poprzeczką znajdująca się w gwiazdozbiorze Smoka w odległości około 11,7 miliona lat świetlnych od Ziemi. Została odkryta 6 kwietnia 1793 roku przez Williama Herschela[2].
Galaktyka ta należy do Grupy galaktyk M81.
Zobacz też
Przypisy
Linki zewnętrzne
- NGC 4236 w serwisie SEDS.org (Revised NGC and IC Catalog) (ang.)
- NGC 4236 w bazie SIMBAD (ang.)
- NGC 4236 w NASA/IPAC Extragalactic Database (ang.)
Media użyte na tej stronie
Autor: NASA Hubble, Licencja: CC BY 2.0
Located just north of the Big Dipper, Caldwell 3 is one of at least 34 gravitationally bound galaxies in the Ursa Major galaxy group. This barred spiral galaxy, also known as NGC 4236, sits 11.7 million light-years from Earth in the constellation Draco and has an apparent magnitude of 9.6. Although faint, Caldwell 3 can be spotted using a small telescope from a dark-sky site. However, the best views are through large telescopes, which show the galaxy as a large, diffuse glow that’s brighter toward the center. It appears highest during the spring in the Northern Hemisphere. It can also be seen from northern latitudes of the Southern Hemisphere in autumn, albeit with a bit more difficulty as it will appear low in the sky. The galaxy was first spotted by British astronomer William Herschel in April 1793.
Barred spiral galaxies are named for the elongated lane of stars that cut through their centers. Not only do these bars often make their galaxies easier to pick out in the night sky due to their needle-like structure, but they can also have profound effects on the dynamics of the galaxies. Bars are thought to direct gas from the spiral arms toward the center of the galaxy, fueling stellar birth. These structures seem to be common in spiral galaxies. Of those that we have observed, nearly two-thirds of spiral galaxies contain a bar, including our Milky Way.
This stunning Hubble image captures a portion of Caldwell 3 and its central bar. It is a composite of four Wide Field and Planetary Camera 2 observations in visible, infrared and ultraviolet. These images were taken in order to constrain the distance of the galaxy from Earth. Using the observable characteristics of some of the brightest stars in Caldwell 3, researchers hoped to determine if it was an isolated galaxy or if it was associated with a group.
Credit: NASA, ESA, P. Seitzer (University of Michigan) and M. Regan (STScI); Processing: Gladys Kober (NASA/Catholic University of America)
For Hubble's Caldwell catalog site and information on how to find these objects in the night sky, visit:
www.nasa.gov/content/goddard/hubble-s-caldwell-catalogAutor: Donald Pelletier, Licencja: CC BY-SA 4.0
"Image created using the Aladin Sky Atlas software from the Strasbourg Astronomical Data Center and DSS (Digitized Sky Survey) data. DSS is one of the programs of STScI (Space Telescope Science Institute) whose files are in the public domain ( http://archive.stsci.edu/data_use.html )" This image is not a DSS's image!