From Wikipedia, the free encyclopedia
Epsilon Piscis Austrini
Location of ε Piscis Austrini (circled)
Observation data
Epoch J2000.0       Equinox J2000.0 ( ICRS)
Constellation Piscis Austrinus
Right ascension 22h 40m 39.34075s [1]
Declination −27° 02′ 37.0157″ [1]
Apparent magnitude (V) +4.17 [2]
Characteristics
Spectral type B8 Ve [3] or B8 IVe [4]
U−B color index −0.31 [2]
B−V color index −0.11 [2]
Astrometry
Radial velocity (Rv)+1.1±2.8 [5] km/s
Proper motion (μ) RA: +23.22 [1]  mas/ yr
Dec.: −0.16 [1]  mas/ yr
Parallax (π)8.0981 ± 0.3582  mas [6]
Distance400 ± 20  ly
(123 ± 5  pc)
Absolute magnitude (MV)−1.66 [4]
Details
Mass4.10±0.19 [7]  M
Radius3.2 [8]  R
Luminosity661 [7]  L
Surface gravity (log g)3.93 [9]  cgs
Temperature11,066 [7]  K
Rotational velocity (v sin i)216 [7] km/s
Other designations
ε PsA, 18 Piscis Austrini, CPD−27° 7442, FK5 854, HD 214748, HIP 111954, HR 8628, SAO 191318 [10]
Database references
SIMBAD data

Epsilon Piscis Austrini, Latinized from ε Piscis Austrini, is a blue-white hued star in the southern constellation of Piscis Austrinus. It is visible to the naked eye with an apparent visual magnitude of +4.17. [2] Based upon an annual parallax shift of 8.0981 ± 0.3582  mas as seen from the GAIA satellite, the system is located roughly 400  light years from the Sun. [6]

This is a B-type main sequence star with a stellar classification of B8 Ve. [3] It is a Be star that is spinning rapidly with a projected rotational velocity of 216 km/s, [7] compared to an equatorial critical velocity of 301 km/s. [9] The star has 4.1 times the mass of the Sun and is radiating 661 times the solar luminosity from its photosphere at an effective temperature of 11,066 K. [7]

Epsilon Piscis Austrini is moving through the Galaxy at a speed of 18.7 km/s relative to the Sun. Its projected Galactic orbit carries it between 23,917 and 28,138 light-years from the center of the Galaxy. [11]

Naming

In Chinese, 羽林軍 (Yǔ Lín Jūn), meaning Palace Guard, refers to an asterism consisting of:

Consequently, the Chinese name for ε Piscis Austrini itself is 羽林軍八 (Yǔ Lín Jūn bā, English: the Eighth Sixth Star of Palace Guard.) [12]

References

  1. ^ a b c d 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 Feinstein, A.; Marraco, H. G. (November 1979), "The photometric behavior of Be Stars", Astronomical Journal, 84: 1713–1725, Bibcode: 1979AJ.....84.1713F, doi: 10.1086/112600.
  3. ^ a b Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode: 2002ApJ...573..359A, doi: 10.1086/340590.
  4. ^ a b 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.
  5. ^ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv: 1606.08053, Bibcode: 2006AstL...32..759G, doi: 10.1134/S1063773706110065, S2CID  119231169.
  6. ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv: 1804.09365. Bibcode: 2018A&A...616A...1G. doi: 10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  7. ^ a b c d e f Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv: 1201.2052, Bibcode: 2012A&A...537A.120Z, doi: 10.1051/0004-6361/201117691, S2CID  55586789.
  8. ^ Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (3rd ed.): 521–524, arXiv: astro-ph/0012289, Bibcode: 2001A&A...367..521P, doi: 10.1051/0004-6361:20000451, S2CID  425754.
  9. ^ a b Chauville, J.; et al. (November 2001), "High and intermediate-resolution spectroscopy of Be stars 4481 lines", Astronomy and Astrophysics, 378: 8618–82, Bibcode: 2001A&A...378..861C, doi: 10.1051/0004-6361:20011202, hdl: 11336/36962.
  10. ^ "eps PsA -- Be Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-05-18.
  11. ^ 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.
  12. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 7 日 Archived 2011-05-21 at the Wayback Machine
From Wikipedia, the free encyclopedia
Epsilon Piscis Austrini
Location of ε Piscis Austrini (circled)
Observation data
Epoch J2000.0       Equinox J2000.0 ( ICRS)
Constellation Piscis Austrinus
Right ascension 22h 40m 39.34075s [1]
Declination −27° 02′ 37.0157″ [1]
Apparent magnitude (V) +4.17 [2]
Characteristics
Spectral type B8 Ve [3] or B8 IVe [4]
U−B color index −0.31 [2]
B−V color index −0.11 [2]
Astrometry
Radial velocity (Rv)+1.1±2.8 [5] km/s
Proper motion (μ) RA: +23.22 [1]  mas/ yr
Dec.: −0.16 [1]  mas/ yr
Parallax (π)8.0981 ± 0.3582  mas [6]
Distance400 ± 20  ly
(123 ± 5  pc)
Absolute magnitude (MV)−1.66 [4]
Details
Mass4.10±0.19 [7]  M
Radius3.2 [8]  R
Luminosity661 [7]  L
Surface gravity (log g)3.93 [9]  cgs
Temperature11,066 [7]  K
Rotational velocity (v sin i)216 [7] km/s
Other designations
ε PsA, 18 Piscis Austrini, CPD−27° 7442, FK5 854, HD 214748, HIP 111954, HR 8628, SAO 191318 [10]
Database references
SIMBAD data

Epsilon Piscis Austrini, Latinized from ε Piscis Austrini, is a blue-white hued star in the southern constellation of Piscis Austrinus. It is visible to the naked eye with an apparent visual magnitude of +4.17. [2] Based upon an annual parallax shift of 8.0981 ± 0.3582  mas as seen from the GAIA satellite, the system is located roughly 400  light years from the Sun. [6]

This is a B-type main sequence star with a stellar classification of B8 Ve. [3] It is a Be star that is spinning rapidly with a projected rotational velocity of 216 km/s, [7] compared to an equatorial critical velocity of 301 km/s. [9] The star has 4.1 times the mass of the Sun and is radiating 661 times the solar luminosity from its photosphere at an effective temperature of 11,066 K. [7]

Epsilon Piscis Austrini is moving through the Galaxy at a speed of 18.7 km/s relative to the Sun. Its projected Galactic orbit carries it between 23,917 and 28,138 light-years from the center of the Galaxy. [11]

Naming

In Chinese, 羽林軍 (Yǔ Lín Jūn), meaning Palace Guard, refers to an asterism consisting of:

Consequently, the Chinese name for ε Piscis Austrini itself is 羽林軍八 (Yǔ Lín Jūn bā, English: the Eighth Sixth Star of Palace Guard.) [12]

References

  1. ^ a b c d 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 Feinstein, A.; Marraco, H. G. (November 1979), "The photometric behavior of Be Stars", Astronomical Journal, 84: 1713–1725, Bibcode: 1979AJ.....84.1713F, doi: 10.1086/112600.
  3. ^ a b Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode: 2002ApJ...573..359A, doi: 10.1086/340590.
  4. ^ a b 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.
  5. ^ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv: 1606.08053, Bibcode: 2006AstL...32..759G, doi: 10.1134/S1063773706110065, S2CID  119231169.
  6. ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv: 1804.09365. Bibcode: 2018A&A...616A...1G. doi: 10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  7. ^ a b c d e f Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv: 1201.2052, Bibcode: 2012A&A...537A.120Z, doi: 10.1051/0004-6361/201117691, S2CID  55586789.
  8. ^ Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (3rd ed.): 521–524, arXiv: astro-ph/0012289, Bibcode: 2001A&A...367..521P, doi: 10.1051/0004-6361:20000451, S2CID  425754.
  9. ^ a b Chauville, J.; et al. (November 2001), "High and intermediate-resolution spectroscopy of Be stars 4481 lines", Astronomy and Astrophysics, 378: 8618–82, Bibcode: 2001A&A...378..861C, doi: 10.1051/0004-6361:20011202, hdl: 11336/36962.
  10. ^ "eps PsA -- Be Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-05-18.
  11. ^ 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.
  12. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 7 日 Archived 2011-05-21 at the Wayback Machine

Videos

Youtube | Vimeo | Bing

Websites

Google | Yahoo | Bing

Encyclopedia

Google | Yahoo | Bing

Facebook