IC 4651

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IC 4651
The rich star cluster IC 4651.jpg
Open cluster IC 4651 taken by the Wide Field Imager (WFI) camera, on the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory in Chile. [1]
Observation data (J2000 epoch)
Right ascension 17h 24m 49s [2]
Declination −49° 56′ 00″ [2]
Distance 2,900 ly (888 [3]   pc)
Apparent dimensions (V)10.0' (arcmin)
Physical characteristics
Other designations Cr 327, Mel 169
Associations
Constellation Ara
See also: Open cluster, List of open clusters

IC 4651 is an open cluster of stars located about 2,900 light years distant in the constellation Ara. It was first catalogued by John Louis Emil Dreyer in his 1895 version of the Index Catalogue . [4] This is an intermediate age cluster that is 1.2 ± 0.2 billion years old. [5] Compared to the Sun, the members of this cluster have a higher abundance of the chemical elements other than hydrogen and helium. [6] The combined mass of the active stars in this cluster is about 630 times the mass of the Sun. [7]

The currently known active stars in this cluster form only about 7% of the cluster's original mass. Of the remainder, about 35% of the mass consists of stars that have evolved into white dwarfs or other stellar remnants. The remainder of lost mass consists of stars that have migrated away from the main body of the cluster or have been lost completely. [7]

The star IC 4651 9122 displays radial velocity variations suggesting the presence of a planetary companion, though stellar activity cannot be completely ruled out. [8] [9] [10]

Related Research Articles

<span class="mw-page-title-main">Ara (constellation)</span> Constellation in the southern celestial hemisphere

Ara is a southern constellation between Scorpius, Telescopium, Triangulum Australe, and Norma. It was one of the Greek bulk described by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations designated by the International Astronomical Union.

<span class="mw-page-title-main">Epsilon Indi</span> Star system in the constellation of Indus

Epsilon Indi, Latinized from ε Indi, is a star system located at a distance of approximately 12 light-years from Earth in the southern constellation of Indus. The star has an orange hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.674. It consists of a K-type main-sequence star, ε Indi A, and two brown dwarfs, ε Indi Ba and ε Indi Bb, in a wide orbit around it. The brown dwarfs were discovered in 2003. ε Indi Ba is an early T dwarf (T1) and ε Indi Bb a late T dwarf (T6) separated by 0.6 arcseconds, with a projected distance of 1460 AU from their primary star.

HR 7703 is a binary star system in the constellation of Sagittarius. The brighter component has an apparent visual magnitude of 5.31, which means it is visible from suburban skies at night. The two stars are separated by an angle of 7.10″, which corresponds to an estimated semimajor axis of 56.30 AU for their orbit.

56 Andromedae, abbreviated 56 And, is a probable binary star system in the northern constellation of Andromeda. 56 Andromedae is the Flamsteed designation. It has a combined apparent visual magnitude of 5.69, which is just bright enough to be dimly visible to the naked eye under good seeing conditions. The distance to this system can be ascertained from its annual parallax shift, measured at 9.9 mas with the Gaia space observatory, which yields a separation of 330 light years. It is moving further from the Earth with a heliocentric radial velocity of +62 km/s and is traversing the celestial sphere at a relatively high rate of 0.183″ per year. This pair is positioned near the line of sight to the open cluster NGC 752, located 1,490 light-years away.

Sigma3 Cancri is a solitary, yellow-hued star in the zodiac constellation of Cancer. With an apparent visual magnitude of +5.24, it is a dim star that is visible to the naked eye. Based upon an annual parallax shift of 11.03 mas as seen from Earth, it is located around 296 light years from the Sun. The star's proper motion makes it a candidate for membership in the IC 2391 supercluster.

<span class="mw-page-title-main">Gliese 667</span> Triple star system in the constellation Scorpius

Gliese 667 is a triple-star system in the constellation Scorpius lying at a distance of about 7.2 parsecs from Earth. All three of the stars have masses smaller than the Sun. There is a 12th-magnitude star close to the other three, but it is not gravitationally bound to the system. To the naked eye, the system appears to be a single faint star of magnitude 5.89.

HD 222582 is a multiple star system in the equatorial constellation of Aquarius. It is invisible to the naked eye with an apparent visual magnitude of 7.7, but can be viewed with binoculars or a small telescope. The system is located at a distance of 137 light years from the Sun based on parallax, and it is drifting further away with a radial velocity of +12 km/s. It is located close enough to the ecliptic that it is subject to lunar occultations.

<span class="mw-page-title-main">IC 2391</span> Open star cluster in the constellation Vela

IC 2391 is an open cluster in the constellation Vela consisting of hot, young, blueish stars, some of which binaries and one of which is a quadruple. Persian astronomer A. a.-R. al-Sufi first described it as "a nebulous star" in c. 964. It was re-found by Abbe Lacaille and cataloged as Lac II 5.

NGC 2423-3 is a red giant star approximately 3,040 light-years away in the constellation of Puppis. The star is part of the NGC 2423 open cluster. The star has an apparent magnitude of 10 and an absolute magnitude of zero, with a mass of 2.4 times the Sun. In 2007, it was proposed that an exoplanet orbits the star, but this is now doubtful.

NGC 4349-127 is a probable red giant star approximately 6,100 light-years away in the constellation of Crux. It is a member of the open cluster NGC 4349. Its mass is estimated at 3.9 times Solar, and its age is about 200 million years.

<span class="mw-page-title-main">EQ Virginis</span> Star in the constellation Virgo

EQ Virginis is a single variable star in the equatorial constellation of Virgo. It has a baseline visual apparent magnitude of 9.36, but is a flare star that undergoes sporadic bursts of brightening. The star is located at a distance of 67 light-years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −23 km/s. It is a member of the IC 2391 moving group of stars, which is between 30 and 50 million years old.

81 Ceti is a star located approximately 331 light years away from the Sun in the equatorial constellation of Cetus. 81 Ceti is the Flamsteed designation for this object. It is visible to the naked eye as a dim, yellow-hued point of light with an apparent visual magnitude of 5.65. The star is drifting further away from the Earth with a heliocentric radial velocity of +9 km/s.

Gamma Comae Berenices, Latinized from γ Comae Berenices, is a single, orange-hued star in the northern constellation of Coma Berenices. It is faintly visible to the naked eye, having an apparent visual magnitude of 4.36. Based upon an annual parallax shift of 19.50 mas as seen from Earth, its distance can be estimated as around 167 light years from the Sun. The star is moving away from the Sun with a radial velocity of +3 km/s.

<span class="mw-page-title-main">NGC 2506</span> Open cluster in the constellation Monoceros

NGC 2506 is a mildly-elongated open cluster of stars in the equatorial constellation of Monoceros, located at a distance of 12.7 kly from the Sun near the Galactic anti-center. It was discovered by William Herschel in 1791. The cluster lies around 10,000 ly from the Galactic Center and about 1,600 ly above the Galactic plane. It is of intermediate age, estimated at around two billion years. The cluster has an angular radius of 12′ and a core radius of 4.8′.

7 Comae Berenices is a single star located 249 light years away in the northern constellation of Coma Berenices. It is a dim star but visible to the naked eye near the Coma Star Cluster with an apparent visual magnitude of 4.93. The star is moving closer to the Earth with a heliocentric radial velocity of −28 km/s, and is predicted to come as close as 83 light-years in 2.4 million years.

Pi<sup>6</sup> Orionis Star in the constellation Orion

Pi6 Orionis (π6 Ori, π6 Orionis) is a solitary star in the eastern part of the constellation Orion. It is visible to the naked eye with an apparent visual magnitude of 4.469. Based upon an annual parallax shift of 3.45 mas, it is around 950 light-years from the Sun. At that distance, the visual magnitude of the star is reduced by an interstellar absorption factor of 0.52.

<span class="mw-page-title-main">NGC 4349</span> Open cluster in the constellation Crux

NGC 4349 is an open cluster in the constellation Crux. It was discovered by James Dunlop in 1826. It is located approximately 7,000 light years away from Earth.

References

  1. ↑ "Sibling Stars" . Retrieved 19 August 2015.
  2. 1 2 Xin, Y.; Deng, L. (February 2005). "Blue Stragglers in Galactic Open Clusters and Integrated Spectral Energy Distributions". The Astrophysical Journal. 619 (2): 824–838. arXiv: astro-ph/0410325 . Bibcode:2005ApJ...619..824X. doi:10.1086/426681. S2CID   2087723.
  3. ↑ Dias, W.S.; Alessi, B.S.; Moitinho, A.; Lepine. J.R.D. (July 2002). "New catalog of optically visible open clusters and candidates". Astronomy and Astrophysics. 389 (3): 871–873. arXiv: astro-ph/0203351 . Bibcode:2002A&A...389..871D. doi:10.1051/0004-6361:20020668. S2CID   18502004. Note: see the VizieR catalogue B/ocl.
  4. ↑ Dreyer, J. L. E. (1895). "Index Catalogue of Nebulae found in the years 1888 to 1894, with Notes and Corrections to the New General Catalogue". Memoirs of the Royal Astronomical Society. 51: 185–228. Bibcode:1895MmRAS..51..185D.
  5. ↑ Biazzo, K.; et al. (December 2007). "Deriving temperature, mass, and age of evolved stars from high-resolution spectra. Application to field stars and the open cluster IC 4651". Astronomy and Astrophysics. 475 (3): 981–989. arXiv: 0704.3192 . Bibcode:2007A&A...475..981B. doi:10.1051/0004-6361:20077374. S2CID   14293731.
  6. ↑ Pasquini, L.; et al. (September 2004). "Detailed chemical composition of the open cluster IC 4651: The iron peak, α elements, and Li". Astronomy and Astrophysics. 424: 951–963. arXiv: astro-ph/0406113 . Bibcode:2004A&A...424..951P. doi:10.1051/0004-6361:20040240. S2CID   605163. This source gives a metallicity value of , which is equivalent to 125% of the Sun's abundance of Iron.
  7. 1 2 Meibom, S.; Andersen, J.; Nordström, B. (April 2002). "Critical tests of stellar evolution in open clusters. III. Stellar population and dynamical evolution of IC 4651". Astronomy and Astrophysics. 386: 187–203. Bibcode:2002A&A...386..187M. doi: 10.1051/0004-6361:20020183 .
  8. ↑ Leão, I. C.; Canto Martins, B. L.; et al. (December 2018). "Incidence of planet candidates in open clusters and a planet confirmation". Astronomy & Astrophysics . 620: A139. arXiv: 1807.03196 . Bibcode:2018A&A...620A.139L. doi:10.1051/0004-6361/201833123.
  9. ↑ Delgado Mena, E.; Lovis, C.; et al. (November 2018). "Planets around evolved intermediate-mass stars. II. Are there really planets around IC 4651 No. 9122, NGC 2423 No. 3, and NGC 4349 No. 127?". Astronomy & Astrophysics . 619: A2. arXiv: 1807.09608 . Bibcode:2018A&A...619A...2D. doi:10.1051/0004-6361/201833152. S2CID   119483881.
  10. ↑ Delgado Mena, E.; Gomes da Silva, J.; et al. (November 2023). "Planets around evolved intermediate-mass stars. III. Planet candidates and long-term activity signals in six open clusters". Astronomy & Astrophysics . 679: A94. arXiv: 2309.13589 . Bibcode:2023A&A...679A..94D. doi:10.1051/0004-6361/202346890.


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