From Wikipedia, the free encyclopedia
τ7 Eridani
Observation data
Epoch J2000.0       Equinox J2000.0 ( ICRS)
Constellation Eridanus
Right ascension 03h 47m 39.65058s [1]
Declination −23° 52′ 28.8352″ [1]
Apparent magnitude (V) 5.235 [2]
Characteristics
Spectral type A3 Vs [3]
U−B color index +0.168 [2]
B−V color index +0.067 [2]
Astrometry
Radial velocity (Rv)28.4±0.5 [4] km/s
Proper motion (μ) RA: +47.46 [1]  mas/ yr
Dec.: +49.10 [1]  mas/ yr
Parallax (π)13.00 ± 0.28  mas [1]
Distance251 ± 5  ly
(77 ± 2  pc)
Absolute magnitude (MV)+0.81 [5]
Details
τ7 Eri A
Mass2.03 [6]  M
Luminosity37.6 [7]  L
Surface gravity (log g)3.86±0.2 [8]  cgs
Temperature8,740±200 [8]  K
Rotational velocity (v sin i)18 [8] km/s
Age387 [6]  Myr
Other designations
τ7 Eridani, τ7 Eri, 28 Eridani, CD−24° 1877, HD 23878, HIP 17717, HR 1181, SAO 168836. [9]
Database references
SIMBAD data

Tau7 Eridani is a solitary star in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 5.235. [2] Using the parallax method, the distance to this star can be estimated as around 251  light years. [1]

This is an A-type main sequence star with a stellar classification of A3 Vs, [3] where the 's' indicates it has narrow absorption lines. It may be a chemically peculiar Am star, which means it displays unusual abundances of certain elements in its surface layers. Tau7 Eridani appears to be a low amplitude variable that displays slight fluctuations in luminosity over a period of 7.17 days. It is slowly rotating with a projected rotational velocity of 18 km/s, [8] and is around 387 million years old. [6]

References

  1. ^ a b c d e f van Leeuwen, F. (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, S2CID  18759600.
  2. ^ a b c d Gutierrez-Moreno, Adelina; et al. (1966), "A System of photometric standards", Publications of the Department of Astronomy University of Chile, 1, Publicaciones Universidad de Chile, Department de Astronomy: 1–17, Bibcode: 1966PDAUC...1....1G.
  3. ^ a b Abt, Helmut A.; Morrell, Nidia I. (July 1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement, 99: 135, Bibcode: 1995ApJS...99..135A, doi: 10.1086/192182.
  4. ^ De Bruijne, J. H. J.; Eilers, A.-C. (2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: A61, arXiv: 1208.3048, Bibcode: 2012A&A...546A..61D, doi: 10.1051/0004-6361/201219219, S2CID  59451347.
  5. ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv: 1108.4971, Bibcode: 2012AstL...38..331A, doi: 10.1134/S1063773712050015, S2CID  119257644.
  6. ^ a b c David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv: 1501.03154, Bibcode: 2015ApJ...804..146D, doi: 10.1088/0004-637X/804/2/146, S2CID  33401607.
  7. ^ McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv: 1208.2037, Bibcode: 2012MNRAS.427..343M, doi: 10.1111/j.1365-2966.2012.21873.x, S2CID  118665352.
  8. ^ a b c d Khalack, V.; LeBlanc, F. (July 2015), "Project VeSElkA: Analysis of Balmer Line Profiles of Slowly Rotating Chemically Peculiar Stars", The Astronomical Journal, 150 (1): 10, arXiv: 1505.08158, Bibcode: 2015AJ....150....2K, doi: 10.1088/0004-6256/150/1/2, S2CID  118283214, 2.
  9. ^ "tau07 Eri". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-10-13.{{ cite web}}: CS1 maint: postscript ( link)
From Wikipedia, the free encyclopedia
τ7 Eridani
Observation data
Epoch J2000.0       Equinox J2000.0 ( ICRS)
Constellation Eridanus
Right ascension 03h 47m 39.65058s [1]
Declination −23° 52′ 28.8352″ [1]
Apparent magnitude (V) 5.235 [2]
Characteristics
Spectral type A3 Vs [3]
U−B color index +0.168 [2]
B−V color index +0.067 [2]
Astrometry
Radial velocity (Rv)28.4±0.5 [4] km/s
Proper motion (μ) RA: +47.46 [1]  mas/ yr
Dec.: +49.10 [1]  mas/ yr
Parallax (π)13.00 ± 0.28  mas [1]
Distance251 ± 5  ly
(77 ± 2  pc)
Absolute magnitude (MV)+0.81 [5]
Details
τ7 Eri A
Mass2.03 [6]  M
Luminosity37.6 [7]  L
Surface gravity (log g)3.86±0.2 [8]  cgs
Temperature8,740±200 [8]  K
Rotational velocity (v sin i)18 [8] km/s
Age387 [6]  Myr
Other designations
τ7 Eridani, τ7 Eri, 28 Eridani, CD−24° 1877, HD 23878, HIP 17717, HR 1181, SAO 168836. [9]
Database references
SIMBAD data

Tau7 Eridani is a solitary star in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 5.235. [2] Using the parallax method, the distance to this star can be estimated as around 251  light years. [1]

This is an A-type main sequence star with a stellar classification of A3 Vs, [3] where the 's' indicates it has narrow absorption lines. It may be a chemically peculiar Am star, which means it displays unusual abundances of certain elements in its surface layers. Tau7 Eridani appears to be a low amplitude variable that displays slight fluctuations in luminosity over a period of 7.17 days. It is slowly rotating with a projected rotational velocity of 18 km/s, [8] and is around 387 million years old. [6]

References

  1. ^ a b c d e f van Leeuwen, F. (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, S2CID  18759600.
  2. ^ a b c d Gutierrez-Moreno, Adelina; et al. (1966), "A System of photometric standards", Publications of the Department of Astronomy University of Chile, 1, Publicaciones Universidad de Chile, Department de Astronomy: 1–17, Bibcode: 1966PDAUC...1....1G.
  3. ^ a b Abt, Helmut A.; Morrell, Nidia I. (July 1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement, 99: 135, Bibcode: 1995ApJS...99..135A, doi: 10.1086/192182.
  4. ^ De Bruijne, J. H. J.; Eilers, A.-C. (2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: A61, arXiv: 1208.3048, Bibcode: 2012A&A...546A..61D, doi: 10.1051/0004-6361/201219219, S2CID  59451347.
  5. ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv: 1108.4971, Bibcode: 2012AstL...38..331A, doi: 10.1134/S1063773712050015, S2CID  119257644.
  6. ^ a b c David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv: 1501.03154, Bibcode: 2015ApJ...804..146D, doi: 10.1088/0004-637X/804/2/146, S2CID  33401607.
  7. ^ McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv: 1208.2037, Bibcode: 2012MNRAS.427..343M, doi: 10.1111/j.1365-2966.2012.21873.x, S2CID  118665352.
  8. ^ a b c d Khalack, V.; LeBlanc, F. (July 2015), "Project VeSElkA: Analysis of Balmer Line Profiles of Slowly Rotating Chemically Peculiar Stars", The Astronomical Journal, 150 (1): 10, arXiv: 1505.08158, Bibcode: 2015AJ....150....2K, doi: 10.1088/0004-6256/150/1/2, S2CID  118283214, 2.
  9. ^ "tau07 Eri". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-10-13.{{ cite web}}: CS1 maint: postscript ( link)

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