Gliese 710
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Serpens |
| Right ascension | 18h 19m 50.84215s[1] |
| Declination | –01° 56′ 18.9841″[1] |
| Apparent magnitude (V) | 9.69[2] (9.65–9.69)[3] |
| Characteristics | |
| Spectral type | K7 Vk[4] |
| U−B color index | +1.23[2] |
| B−V color index | +1.36[2] |
| Variable type | Suspected[3] |
| Astrometry | |
| Radial velocity (Rv) | –13.8[5] km/s |
| Proper motion (μ) | RA: +1.15[1] mas/yr Dec.: +1.99[1] mas/yr |
| Parallax (π) | 51.12 ± 1.63 mas |
| Distance | 64 ± 2 ly (19.6 ± 0.6 pc) |
| Absolute magnitude (MV) | 8.7 ± 0.3[citation needed] |
| Details | |
| Mass | 0.6[6] M☉ |
| Radius | 0.67[7] R☉ |
| Luminosity (bolometric) | 0.042[citation needed] L☉ |
| Temperature | 4,250[6] K |
| Rotational velocity (v sin i) | 6.42 ± 0.78[8] km/s |
| Other designations | |
Gliese 710 is a star in the constellation Serpens Cauda with an apparent visual magnitude of 9.69. It has a stellar classification of K7 Vk,[4] which means it is a main sequence star that is generating energy through the thermonuclear fusion of hydrogen at its core. (The suffix 'k' indicates that the spectrum shows absorption lines from interstellar matter.) The mass of this star is about 60%[6] of the Sun's mass and it has an estimated 67% of the Sun's radius.[7] It is a suspected variable star that may vary in magnitude from 9.65–9.69.
This star is currently about 63.8 light-years (19.6 parsecs) from Earth, but its proper motion, distance, and radial velocity[9] indicate that it will approach within a very small distance—perhaps under one light year—from the Sun within 1.4 million years, based on past and current Hipparcos data.[5] At closest approach it will be a first-magnitude star about as bright as Antares. The proper motion of Gliese 710 is very small for its distance, meaning it is traveling nearly directly in our line of sight; compare for example with Arcturus.
In a time interval of ±10 million years from the present, Gliese 710 is the star whose combination of mass and close approach distance will cause the greatest gravitational perturbation of the Solar System.
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[edit] Computing and details of the closest approach
Gliese 710 has the potential to perturb the hypothetical Oort cloud enough to send a shower of comets into the inner Solar System, possibly causing an impact event. However, dynamic models by García-Sánchez, et al. in 1999 indicate that the net increase in cratering rate due to the passage of Gliese 710 will be no more than 5%.[6] They estimate that the closest approach will happen in 1,360,000 years when the star will approach within 0.337 ± 0.177 parsecs (1.1 light-years) of the Sun.[10]
More recent calculations by Bobylev in 2010 suggest Gliese 710 has an 86 percent chance of passing through the Oort cloud, considering the Oort cloud to be a spheroid around the Sun with semiminor and semimajor axes of 80,000 and 100,000 astronomical units. The distance of closest approach of Gliese 710 is difficult to compute precisely as it depends sensitively on its current position and velocity; Bobylev estimates that it will pass within 0.311 ± 0.167 pc (1.01 ± 0.54 light years) of the Sun.[5] There is even a 1/10,000 chance of the star penetrating into the region (d < 1,000 AU) where the influence of the passing star on Kuiper belt objects is significant.[5]
The star with the second greatest perturbational effect in the past or future 10 million years was Algol,[6] a triple star system that passed no closer than 9.8 light years, 7.3 million years ago, but with a considerably larger total mass of 5.8 solar masses.
[edit] See also
[edit] References
- ^ a b c d van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode 2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- ^ a b c d "Gliese 710". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Gliese+710. Retrieved 2010-03-18.
- ^ a b Kukarkin, B. V. et al. (1971), "The third edition containing information on 20437 variable stars discovered and designated till 1968", General Catalogue of Variable Stars (3rd ed.), Bibcode 1971GCVS3.C......0K
- ^ a b Gray, R. O. et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I". The Astronomical Journal 132 (1): 161–170. Bibcode 2006AJ....132..161G. doi:10.1086/504637.
- ^ a b c d Bobylev, Vadim V. (March 2010). "Searching for Stars Closely Encountering with the Solar System". Astronomy Letters 36 (3): 220–226. arXiv:1003.2160. Bibcode 2010AstL...36..220B. doi:10.1134/S1063773710030060.
- ^ a b c d e García-Sánchez, Joan et al. (February 1999). "Stellar Encounters with the Oort Cloud Based on HIPPARCOS Data". The Astronomical Journal 117 (2): 1042–1055. Bibcode 1999AJ....117.1042G. doi:10.1086/300723.
- ^ a b Johnson, H. M.; Wright, C. D. (November 1983). "Predicted infrared brightness of stars within 25 parsecs of the sun". The Astrophysical Journal Supplement Series 53: 643–711. Bibcode 1983ApJS...53..643J. doi:10.1086/190905.
- ^ López-Santiago, J. et al. (May 2010), "A high-resolution spectroscopic survey of late-type stars: chromospheric activity, rotation, kinematics, and age", Astronomy and Astrophysics 514: A97, Bibcode 2010A&A...514A..97L, doi:10.1051/0004-6361/200913437
- ^ See also: Stellar kinematics.
- ^ García-Sánchez, J.; Weissman, P. R.; Preston, R. A.; Jones, D. L.; Lestrade, J.-F.; Latham, D. W.; Stefanik, R. P.; Paredes, J. M. (2001). "Stellar encounters with the solar system". Astronomy and Astrophysics 379 (2): 634–659. Bibcode 2001A&A...379..634G. doi:10.1051/0004-6361:20011330.
[edit] Further reading
- García-Sánchez, Joan et al. (1999). "Stellar encounters with the Oort cloud based on Hipparcos data". The Astronomical Journal 117 (2): 1042–1055. Bibcode 1999AJ....117.1042G. doi:10.1086/300723.
- García-Sánchez, J.; Weissman, P. R.; Preston, R. A.; Jones, D. L.; Lestrade, J.-F.; Latham, D. W.; Stefanik, R. P.; Paredes, J. M. (2001). "Stellar encounters with the solar system". Astronomy and Astrophysics 379 (2): 634–659. Bibcode 2001A&A...379..634G. doi:10.1051/0004-6361:20011330.
- Bobylev, Vadim V. (2010). "Searching for Stars Closely Encountering with the Solar System". Astronomy Letters 36 (3): 220–226. arXiv:1003.2160. Bibcode 2010AstL...36..220B. doi:10.1134/S1063773710030060.
[edit] External links
- SolStation.com
- VizieR variable star database
- Wikisky image of HD 168442 (Gliese 710)
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