Terzan 5
|
Globular cluster data from Terzan 5 |
|
|---|---|
|
|
| Photo from the Hubble Space Telescope | |
| AladinLite | |
| Constellation | Sagittarius |
|
Position equinox : J2000.0 , epoch : J2000.0 |
|
| Right ascension | 17 h 48 m 04.85 s |
| declination | -24 ° 46 ′ 44.6 ″ |
| Appearance | |
| Brightness (visual) | +13.85 mag |
| Angular expansion | 9.8 ' |
| Physical data | |
| Affiliation | Milky Way |
| Redshift | - (314 ± 50) · 10 −6 |
| Radial velocity | (-85 ± 10) km / s |
| distance | 19,000 ± 1600 ly (5900 ± 500 pc ) |
| Age | 12 billion / 6 billion years |
| Metallicity [Fe / H] | -0.2 / +0.3 |
| history | |
| discovery | Agop Terzan |
| Discovery date | 1968 |
| Catalog names | |
| C 1745-247 • GCl 76.1 • ESO 520-27 • | |
Terzan 5 is a globular cluster in the constellation Sagittarius , which was originally assumed to be 10.3 kpc (approx. 33,600 ly ) from Earth and 2.4 kpc from the galactic center. Measurements from 1996, 2007 and 2009, however, suggest a shorter distance to our solar system . Current estimates assume a distance of (5.9 ± 0.5) kpc ((19000 ± 1600) ly ) from Earth , but Terzan 5 is still included in the bulge of our galaxy.
The cluster was discovered by Agop Terzan in 1968 on photographic plates from the Haute Provence observatory in southern France. Terzan later mistakenly "discovered" the same cluster again and published it as Terzan 5 and 11 in the original 1971 publication.
In contrast to the vast majority of globular clusters, which consist of only one star population , Terzan 5 was formed in two bursts. One population arose 12 billion years ago, and a younger one 6 billion years ago. A comparable structure was previously only known from Omega Centauri .
Since studies by the VLT showed that Terzan 5 has a greater mass than originally assumed, in connection with its complex composition it is assumed that it is a remnant of a dwarf galaxy captured in the early stages of our Milky Way .
At least 20 pulsars , including the fastest rotating millisecond pulsar to date, PSR J1748-2446ad, were discovered in Terzan 5 .
Web links
- ESO: Cosmic “dig” finds remains of the basic building blocks of the Milky Way 25 November 2009
- astronews.com: A fossil from the young Milky Way September 8, 2016
- Terzan 5 in "galactic globular clusters database"
Individual evidence
- ↑ a b c d The cluster Terzan 5 as a remnant of a primordial building block of the Galactic bulge, published 11/2009, English (PDF; 1.8 MB)
- ^ A b Students for the Exploration and Development of Space
- ↑ Hitting the Pulsar Jackpot in Terzan 5 with the GBT , published 12/2004, bibcode : 2004AAS ... 20511102R (English)