Astronomy:Zeta Leporis
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Lepus |
| Right ascension | 05h 46m 57.34096s[1] |
| Declination | −14° 49′ 19.0199″[1] |
| Apparent magnitude (V) | 3.524[2] |
| Characteristics | |
| Spectral type | A2 IV-V(n)[3] |
| U−B color index | +0.113[2] |
| B−V color index | +0.114[2] |
| Astrometry | |
| Radial velocity (Rv) | 20.0[4]–24.7[5] km/s |
| Proper motion (μ) | RA: -14.54[1] mas/yr Dec.: -1.07[1] mas/yr |
| Parallax (π) | 46.28 ± 0.16[1] mas |
| Distance | 70.5 ± 0.2 ly (21.61 ± 0.07 pc) |
| Absolute magnitude (MV) | +1.88[6] |
| Details | |
| Mass | 1.46[7] M☉ |
| Radius | 1.5[8] R☉ |
| Luminosity | 14[9] L☉ |
| Surface gravity (log g) | 4.41[9] cgs |
| Temperature | 9,772[10] K |
| Metallicity [Fe/H] | –0.76[3] dex |
| Rotational velocity (v sin i) | 245[8] km/s |
| Age | 231+126 −181[10] Myr |
| Other designations | |
ζ Lep, 14 Leporis, BD–14° 1232, FK5 219, GCTP 1326, Gl 217.1, HD 38678, HIP 27288, HR 1998, SAO 150801, Wolf 9190.[11] | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
Zeta Leporis, Latinized from ζ Leporis, is a star approximately 70.5 light-years (21.6 parsecs) away in the southern constellation of Lepus. It has an apparent visual magnitude of 3.5,[2] which is bright enough to be seen with the naked eye. In 2001, an asteroid belt was confirmed to orbit the star.
Stellar components
Zeta Leporis has a stellar classification of A2 IV-V(n),[3] suggesting that it is in a transitional stage between an A-type main-sequence star and a subgiant. The (n) suffix indicates that the absorption lines in the star's spectrum appear nebulous because it is spinning rapidly, causing the lines to broaden because of the Doppler effect. The projected rotational velocity is 245 km/s,[8] giving a lower limit on the star's actual equatorial azimuthal velocity.
The star has about 1.46 times the mass of the Sun,[7] along with 1.5 times the radius,[8] and 14 times the luminosity.[9] The abundance of elements other than hydrogen and helium, what astronomers term the star's metallicity, is only 17% of the abundance in the Sun.[3] The star appears to be very young, probably around 231 million years in age, but the margin of error spans 50–347 million years old.[10]
Asteroid belt
In 1983, based on radiation in the infrared portion of the electromagnetic spectrum, the InfraRed Astronomical Satellite was used to identify dust orbiting this star. This debris disk is constrained to a diameter of 12.2 AU.[12]
By 2001, the Long Wavelength Spectrometer at the Keck Observatory on Mauna Kea, Hawaii, was used more accurately to constrain the radius of the dust. It was found to lie within a 5.4 AU radius.[12] The temperature of the dust was estimated as about 340 K.[citation needed] Based on heating from the star, this could place the grains as close as 2.5 AU from Zeta Leporis.[12]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| Asteroid belt | 2.5–6.1 AU | — | — | |||
Solar encounter
Bobylev's calculations from 2010 suggest that this star passed as close as 1.28 parsecs (4.17 light-years) from the Sun about 861,000 years ago.[5] García-Sánchez 2001 suggested that the star passed 1.64 parsecs (5.34 light-years) from the Sun about 1 million years ago.[4] It was the brightest star in the night sky over 1 million years ago,[13] peaking with an apparent magnitude of -2.05.[13]
See also
References
- ↑ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 Gutierrez-Moreno, Adelina et al. (1966), "A System of photometric standards", Publications of the Department of Astronomy University of Chile (Publicaciones Universidad de Chile, Department de Astronomy) 1: 1–17, Bibcode: 1966PDAUC...1....1G
- ↑ 3.0 3.1 3.2 3.3 Gray, R. O. et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal 132 (1): 161–170, doi:10.1086/504637, Bibcode: 2006AJ....132..161G
- ↑ 4.0 4.1 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. doi:10.1051/0004-6361:20011330. Bibcode: 2001A&A...379..634G.
- ↑ 5.0 5.1 Bobylev, Vadim V. (March 2010). "Searching for Stars Closely Encountering with the Solar System". Astronomy Letters 36 (3): 220–226. doi:10.1134/S1063773710030060. Bibcode: 2010AstL...36..220B.
- ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 7.0 7.1 Shaya, Ed J.; Olling, Rob P. (January 2011), "Very Wide Binaries and Other Comoving Stellar Companions: A Bayesian Analysis of the Hipparcos Catalogue", The Astrophysical Journal Supplement 192 (1): 2, doi:10.1088/0067-0049/192/1/2, Bibcode: 2011ApJS..192....2S
- ↑ 8.0 8.1 8.2 8.3 Akeson, R. L. et al. (February 2009), "Dust in the inner regions of debris disks around a stars", The Astrophysical Journal 691 (2): 1896–1908, doi:10.1088/0004-637X/691/2/1896, Bibcode: 2009ApJ...691.1896A
- ↑ 9.0 9.1 9.2 Malagnini, M. L.; Morossi, C. (November 1990), "Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars", Astronomy and Astrophysics Supplement Series 85 (3): 1015–1019, Bibcode: 1990A&AS...85.1015M
- ↑ 10.0 10.1 10.2
- ↑ "Gliese 217.1". SIMBAD Astronomical Object Database. Centre de Données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Gliese+217.1.
- ↑ 12.0 12.1 12.2 Morledge, Paul (November 2001). "Tightening a Star's Belt". Astronomy (Kalmbach Publishing) 29 (11): 26. ISSN 0091-6358. http://search.ebscohost.com/login.aspx?direct=true&db=aph&AN=5260952&site=ehost-live.
- ↑ 13.0 13.1 Tomkin, Jocelyn (April 1998). "Once and Future Celestial Kings". Sky and Telescope 95 (4): 59–63. Bibcode: 1998S&T....95d..59T. – based on computations from HIPPARCOS data. (The calculations exclude stars whose distance or proper motion is uncertain.) PDF[yes|permanent dead link|dead link}}]
Further reading
- Cote J (1987). "B and A type stars with unexpectedly large colour excesses at IRAS wavelengths". Astronomy and Astrophysics 181 (1): 77–84. Bibcode: 1987A&A...181...77C.
- Aumann H. H.; Probst R. G. (1991). "Search for Vega-like nearby stars with 12 micron excess". Astrophysical Journal 368: 264–271. doi:10.1086/169690. Bibcode: 1991ApJ...368..264A.
- Chen C. H.; Jura M. (2001). "A Possible Massive Asteroid Belt around zeta Leporis". Astrophysical Journal 560 (2): L171. doi:10.1086/324057. Bibcode: 2001ApJ...560L.171C.
- M. M. Moerchen; C. M. Telesco; C. Packham; T. J. J. Kehoe (2006). "Mid-infrared resolution of a 3 AU-radius debris disk around Zeta Leporis". Astrophysical Journal Letters 655 (2): L109. doi:10.1086/511955. Bibcode: 2007ApJ...655L.109M.
External links
- Britt, Robert Roy (2001-06-04). "Asteroid Belt Like Ours Spotted Around Another Star". SPACE.com. http://www.space.com/scienceastronomy/astronomy/aas_solarsystems_010604.html.
- UCLA astronomers identify evidence of asteroid belt around nearby star: Findings indicate potential for planet or asteroid formation, 2001.
- "Zeta Leporis". SolStation. http://www.solstation.com/stars2/zeta-lep.htm.
- Wikisky image of Zeta Leporis
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