NGC 1222
| Galaxie NGC 1222 | |
|---|---|
 (c) ESA/Hubble, CC BY 4.0 | |
| Die linsenförmige Galaxie NGC 1222, aufgenommen mithilfe des Hubble-Weltraumteleskops | |
| AladinLite | |
| Sternbild | Eridanus |
| Position Äquinoktium: J2000.0, Epoche: J2000.0 | |
| Rektaszension | 03h 08m 56,7s[1] |
| Deklination | −02° 57′ 19″[1] |
| Erscheinungsbild | |
| Morphologischer Typ | S0- / HII / Stbrst[1] |
| Helligkeit (visuell) | 12,5 mag[2] |
| Helligkeit (B-Band) | 13,5 mag[2] |
| Winkelausdehnung | 1,1′ × 0,9′[2] |
| Positionswinkel | 169°[2] |
| Flächenhelligkeit | 12,6 mag/arcmin²[2] |
| Physikalische Daten | |
| Zugehörigkeit | NGC 1222-Gruppe LGG 85[1][3] |
| Rotverschiebung | 0,008079 ± 0,000017[1] |
| Radialgeschwindigkeit | (2422 ± 5) km/s[1] |
| Hubbledistanz H0 = 73 km/(s • Mpc) | (107 ± 8) · 106 Lj (32,9 ± 2,3) Mpc [1] |
| Durchmesser | 35.000 Lj[4] |
| Geschichte | |
| Entdeckung | Edouard Stephan |
| Entdeckungsdatum | 5. Dezember 1883 |
| Katalogbezeichnungen | |
| NGC 1222 • PGC 11774 • MCG -01-09-005 • IRAS 03064-0308 • KUG 0306-031 • 2MASX J03085674-0257187 • Mrk 603 • GALEXASC J030856.74-025718.0 • HIPASS J0308-02 | |
NGC 1222 ist eine linsenförmige Galaxie mit ausgedehnten Sternentstehungsgebieten vom Hubble-Typ S0- im Sternbild Eridanus am Südsternhimmel. Sie ist schätzungsweise 107 Millionen Lichtjahre von der Milchstraße entfernt und hat einen Durchmesser von etwa 35.000 Lichtjahren. Ein am 7. November 2016 veröffentlichtes Hubble-Teleskop-Bild zeigt, dass die Hauptgalaxie zwei Zwerggalaxien absorbiert und Starburst-Aktivitäten in allen drei Galaxien erzeugt.
Gemeinsam mit NGC 1248, PGC 11885, PGC 12068, PGC 12130, und PGC 11968 bildet sie die NGC 1222-Gruppe.
Das Objekt wurde am 5. Dezember 1883 von dem Astronomen Edouard Stephan[5] mithilfe eines 80 cm Spiegelteleskops entdeckt und später von Johan Dreyer in seinem New General Catalogue verzeichnet wurde.
NGC 1222-Gruppe (LGG 85)
| Galaxie | Alternativname | Entfernung/Mio. Lj |
|---|---|---|
| NGC 1222 | PGC 11774 | 107 |
| NGC 1248 | PGC 11970 | 98 |
| PGC 11885 | MCG -01-09-013 | 99 |
| PGC 11968 | Mrk 604 | 95 |
| PGC 12068 | MCG -01-09-021 | 98 |
| PGC 12130 | MCG -01-09-024 | 102 |
Weblinks
- astronews.com: Bild des Tages 8. November 2016
- CDS Portal
- SIMBAD Astronomical Database
- A greedy giant (engl.)
Einzelnachweise
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(c) ESA/Hubble, CC BY 4.0
A greedy giant
NGC 1222, seen in this image taken with the Wide Field Camera 3 on board the NASA/ESA Hubble Space Telescope (HST), is a galaxy with a rather eventful story to tell. NGC 1222 has been described as a peculiar example of a type of galaxy known as a lenticular galaxy. Typically, this kind of galaxy would present a rather smooth appearance on the sky and would consist mostly of old, reddish stars. A bit dull, perhaps.
But NGC 1222 is certainly not a typical member of its class — and it’s anything but dull. Observations show the characteristic features of very recent star formation on a huge scale — an event known as a starburst. The reason for all this violent activity is caused by the fact that NGC 1222 is not alone. It actually contains three compact regions, each of which appears to be the central nucleus of a galaxy. Astronomers think that NGC 1222 is in the process of swallowing up two much smaller dwarf galaxies that strayed too close to it. It is likely that the encounter was the trigger for the starburst in NGC 1222, bringing in fresh supplies of gas that are now fuelling the burst of star formation. Although its peculiarities were first seen in photographic images, these were not able to reveal the level of fine detail that can be recovered by Hubble. The image taken by Hubble allows us to see an astonishing amount of structure in this galaxy, emphasising its colourful history. Against the smooth background of old stars that was the original lenticular galaxy, we can clearly see dark filaments of dust and bright filaments of gas, both associated with the powerful star formation process.
Credit:
ESA/Hubble & NASA
Coordinates Position (RA): 3 8 56.83 Position (Dec): -2° 57' 19.61" Field of view: 2.13 x 1.67 arcminutes Orientation: North is 51.9° left of vertical
Colours & filters Band Wavelength Telescope Optical g 475 nm Hubble Space Telescope WFC3 Optical g 475 nm Hubble Space Telescope WFC3 Optical I 814 nm Hubble Space Telescope WFC3 Optical I 814 nm Hubble Space Telescope WFC3.