| M 4 | |
|---|---|
| Star cluster | |
 | |
| Research history | |
| Discoverer | Jean Philippe de Chesault |
| opening date | 1746 |
| Designations | Messier 4, NGC 6121 |
| Observational data ( Age J2000.0 ) | |
| Type of | Globular cluster |
| Right ascension | |
| Declination | |
| Distance | 7200 St. years (2209 pc ) |
| Visible magnitude (V) | 5,6 |
| Visible Dimensions (V) | 36,0 ′ |
| Constellation | Scorpio |
| physical characteristics | |
| Class | IX |
| Radius | 35 St. years old |
| Absolute magnitude (V) | |
| Age | 13 billion years |
| The properties | located 1.3 ° west of Antares |
Messier 4 ( English M 4 , NGC 6121 , Russian Messier 4 ) is a globular cluster in the constellation Scorpio . It was the first globular cluster in which individual stars were distinguished. Diameter 26 arc minutes, the distance to the cluster is slightly more than 2 kiloparsecs.
Being distant at a distance of 7200 light years , the cluster is apparently the closest of all globular clusters to our solar system . Cluster class - IX. The spatial size is approximately 75 light years across. At least 43 variable stars are observed in this cluster.
Content
Discovery History
The cluster was discovered by Jean Philippe de Chesault in 1746 and cataloged by Charles Messier in 1764 .
Interesting features
In 1987, a millisecond pulsar with a period of 3.0 milliseconds was discovered in the M 4 cluster, which is ten times faster than that of the Crab Pulsar . The photographs taken by the Hubble telescope in 1995 revealed a number of stars - white dwarfs , which belong to the oldest known stars in the Milky Way Galaxy with an age of 13 billion years . One of the discovered white dwarfs is a binary star with a pulsar companion, PSR B1620-26 and a planet orbiting around it with a mass of 2.5 times that of Jupiter .
Observations
M 4, despite the relatively high brightness of the cluster, it is difficult to observe in central Russia, where the constellation Scorpio is visible not high above the horizon. But in the southern latitudes it is a fairly easy object for amateur observations, especially considering the presence of such a bright landmark as Antares (a bright orange star - α Scorpio) in a half degrees east. The diffuse spot of the cluster is already visible through field binoculars . A small telescope or telescope allows individual stars in it, of which the brightest has a visible magnitude of 10.8 m . In a telescope with an aperture of up to 100 mm, this globular cluster is visible as a foggy spot, with few stars in its background. At 150 mm, the spherical shape of the cluster and already many stars become clearly visible. At 200 mm, it scatters into dozens of stars to the very center. In addition, the somewhat irregular shape of this very rarefied cluster is already clearly visible.
Neighbors in the Sky from Messier Catalog
- M 80 - (to the northwest, also in Scorpio) - a compact and condensed globular cluster - the exact opposite of M 4;
- M 62 and M 19 - (east and southeast, in Ophiuchus ), globular clusters;
- M 9 - (to the northeast, in Ophiuchus) - globular cluster
Sequence of Observation at the Messier Marathon
... M 80 → M 56 → M 4 → M 29 → M 14 ...
Images
Gal. Longitude 350.9729 °
Gal. + 15.9722 °
Distance 7,200 St. years old
See also
- List of Messier objects
- New General Catalog
Notes
- ↑ Harris W. E. A catalog of parameters for globular clusters in the Milky Way // Astron. J. / J. G. III - IOP Publishing , 1996. - Vol. 112, Iss. 4. - P. 1487-1488. - ISSN 0004-6256 ; 1538-3881 - doi: 10.1086 / 118116
Links
- Information in English and French from the original “ New General Catalog ”
- Information (Eng.) From the Revised New General Catalog
- SIMBAD
- VizieR (English)
- NASA / IPAC Extragalactic Database
- List of publications on NGC 6121
- M 4, SEDS Messier pages
- Miranda Magazine, Astronet - An exoplanet article in M 4