Messier 102
| Galaxie Messier 102 | |
|---|---|
 | |
| Die linsenförmige Galaxie M102 aufgenommen vom Hubble-Weltraumteleskop. | |
| AladinLite | |
| Sternbild | Drache |
| Position Äquinoktium: J2000.0, Epoche: J2000.0 | |
| Rektaszension | 15h 6m 29,5s[1] |
| Deklination | +55° 45′ 48″[1] |
| Erscheinungsbild | |
| Morphologischer Typ | S0_3 HII/LINER[1] |
| Helligkeit (visuell) | 9,9 mag[2] |
| Helligkeit (B-Band) | 10,8 mag[2] |
| Winkelausdehnung | 6,5′ × 3,1′[2] |
| Positionswinkel | 128°[2] |
| Flächenhelligkeit | 13,0 mag/arcmin²[2] |
| Physikalische Daten | |
| Zugehörigkeit | LGG 396[3] |
| Rotverschiebung | 0,002518 ± 0,000017[1] |
| Radialgeschwindigkeit | (755 ± 5) km/s[1] |
| Hubbledistanz vrad / H0 | (40 ± 3) · 106 Lj (12,3 ± 0,9) Mpc [1] |
| Durchmesser | 60.000 Lj |
| Geschichte | |
| Entdeckung | Pierre Méchain |
| Entdeckungsdatum | 27. März 1781[4] |
| Katalogbezeichnungen | |
| M 102 • NGC 5866 • UGC 9723 • PGC 53933 • CGCG 274-016 • MCG +09-25-017 • IRAS 15051+5557 • GC 4058 • h 1909 • H I 215 | |
Messier 102 (M 102, auch als NGC 5866 bezeichnet) ist eine linsenförmige Galaxie mit den Abmessungen 6,5′ × 3,1′ und der scheinbaren Helligkeit von 9,9 mag im Sternbild Drache. Da sie als der Prototyp einer linsenförmigen Galaxie, d. h. einer Galaxie vom Hubble-Typ S0, angesehen wird, ist sie auch unter dem Namen Spindelgalaxie bekannt. Dieser Name ist allerdings mehrdeutig, da beispielsweise auch auf die ebenfalls linsenförmige Galaxie NGC 3115 unter demselben Namen Bezug genommen wird.
Heute wird M 102 allgemein dem NGC-Objekt NGC 5866 zugeordnet. Allerdings besteht eine Kontroverse, ob Messier tatsächlich diese Galaxie gemeint hatte, oder ob es sich bei M 102 um eine Doppelbeobachtung von M 101 handelt. Andere vermuten, dass Messier stattdessen NGC 5879 oder NGC 5928 gemeint hat, allerdings sind beide lichtschwächer als NGC 5866. Ursprünglich beobachtet wurde der Eintrag Nummer 102 in Messiers Katalog von Pierre Méchain, doch der Übertrag in Messiers endgültigen Katalog geschah in Eile und ohne Koordinatenangaben; lediglich mit der fehlerhaften Beschreibung, dass der Ort des Nebels zwischen den Sternen ο Boo und ι Dra sei.
Weblinks
- Spektrum.de: Amateuraufnahmen [1]
- M102 bei SEDS
- NGC 5866 bei SEDS
- Eine Aufnahme mit dem Hubble-Weltraumteleskop
Einzelnachweise
Auf dieser Seite verwendete Medien
Bildtafel Messierobjekte.jpg
Autor/Urheber:
Bildtafel der 110 Messier-Objekte.
Autor/Urheber:
diverse
, Lizenz: CC-by 3.0Bildtafel der 110 Messier-Objekte.
Ngc5866 hst big.jpg
From original NASA press release:
From original NASA press release:
- This is a unique view of the disk galaxy NGC 5866 tilted nearly edge-on to our line-of-sight. Hubble's sharp vision reveals a crisp dust lane dividing the galaxy into two halves. The image highlights the galaxy's structure: a subtle, reddish bulge surrounding a bright nucleus, a blue disk of stars running parallel to the dust lane, and a transparent outer halo. NGC 5866 is a disk galaxy of type "S0" (pronounced s-zero). Viewed face on, it would look like a smooth, flat disk with little spiral structure. It remains in the spiral category because of the flatness of the main disk of stars as opposed to the more spherically rotund (or ellipsoidal) class of galaxies called ellipticals. Such S0 galaxies, with disks like spirals and large bulges like ellipticals, are called lenticular galaxies. NGC 5866 lies in the Northern constellation Draco, at a distance of 44 million light-years. It has a diameter of roughly 60,000 light-years only two-thirds the diameter of the Milky Way, although its mass is similar to our galaxy. This Hubble image of NGC 5866 is a combination of blue, green and red observations taken with the Advanced Camera for Surveys in February 2006.
And from the image's page:
- This is a unique NASA Hubble Space Telescope view of the disk galaxy NGC 5866 tilted nearly edge-on to our line-of-sight.
- Hubble's sharp vision reveals a crisp dust lane dividing the galaxy into two halves. The image highlights the galaxy's structure: a subtle, reddish bulge surrounding a bright nucleus, a blue disk of stars running parallel to the dust lane, and a transparent outer halo.
- Some faint, wispy trails of dust can be seen meandering away from the disk of the galaxy out into the bulge and inner halo of the galaxy. The outer halo is dotted with numerous gravitationally bound clusters of nearly a million stars each, known as globular clusters. Background galaxies that are millions to billions of light-years farther away than NGC 5866 are also seen through the halo.
- NGC 5866 is a disk galaxy of type "S0" (pronounced s-zero). Viewed face on, it would look like a smooth, flat disk with little spiral structure. It remains in the spiral category because of the flatness of the main disk of stars as opposed to the more spherically rotund (or ellipsoidal) class of galaxies called "ellipticals." Such S0 galaxies, with disks like spirals and large bulges like ellipticals, are called 'lenticular' galaxies.
- The dust lane is slightly warped compared to the disk of starlight. This warp indicates that NGC 5866 may have undergone a gravitational tidal disturbance in the distant past, by a close encounter with another galaxy. This is plausible because it is the largest member of a small cluster known as the NGC 5866 group of galaxies. The starlight disk in NGC 5866 extends well beyond the dust disk. This means that dust and gas still in the galaxy and potentially available to form stars does not stretch nearly as far out in the disk as it did when most of these stars in the disk were formed.
- The Hubble image shows that NGC 5866 shares another property with the more gas-rich spiral galaxies. Numerous filaments that reach out perpendicular to the disk punctuate the edges of the dust lane. These are short-lived on an astronomical scale, since clouds of dust and gas will lose energy to collisions among themselves and collapse to a thin, flat disk.
- For spiral galaxies, the incidence of these fingers of dust correlates well with indicators of how many stars have been formed recently, as the input of energy from young massive stars moves gas and dust around to create these structures. The thinness of dust lanes in S0s has been discussed in ground-based galaxy atlases, but it took the resolution of Hubble to show that they can have their own smaller fingers and chimneys of dust.
- NGC 5866 lies in the Northern constellation Draco, at a distance of 44 million light-years (13.5 Megaparsecs). It has a diameter of roughly 60,000 light-years (18,400 parsecs) only two-thirds the diameter of the Milky Way, although its mass is similar to our galaxy. This Hubble image of NGC 5866 is a combination of blue, green and red observations taken with the Advanced Camera for Surveys in November 2005.