Pi Serpentis

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Pi Serpentis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Serpens
Right ascension 16h 02m 17.69166s[1]
Declination +22° 48′ 16.0302″[1]
Apparent magnitude (V) 4.82[2]
Spectral type A3 V[3]
U−B color index +0.10[2]
B−V color index +0.06[2]
Radial velocity (Rv) −28.2±4.2[4] km/s
Proper motion (μ) RA: +4.03[1] mas/yr
Dec.: +23.60[1] mas/yr
Parallax (π) 18.22 ± 0.26[1] mas
Distance 179 ± 3 ly
(54.9 ± 0.8 pc)
Absolute magnitude (MV) 1.12[5]
Mass 2.50[6] M
Radius 2.27[7] R
Luminosity 27[8] L
Surface gravity (log g) 4.040[9] cgs
Temperature 7,566±12[10] K
Metallicity [Fe/H] 0.380[9] dex
Rotational velocity (v sin i) 128[11] km/s
Age 320[6] Myr
Other designations
π Ser, 44 Serpentis, BD+23° 2886, FK5 3268, HD 143894, HIP 78554, HR 5972, SAO 84155[12]
Database references

Pi Serpentis, Latinized from π Serpentis, is a solitary[13] white-hued star in the constellation Serpens, located in its head, Serpens Caput. Based upon an annual parallax shift of 18.22 mas as seen from Earth, it is located around 179 light years from the Sun. It is visible to the naked eye with an apparent visual magnitude of 4.82.[2]

This is a A-type main sequence star with a stellar classification of A3 V.[3] It is about 320[6] million years old with a high rate of spin, measured at a 128[11] km/s projected rotational velocity. The star has an estimated 2.50[6] times the mass of the Sun and 2.27[7] times the Sun's radius. It is radiating 27[8] times the solar luminosity from its photosphere at an effective temperature of 7,566 K.[10]

In 1992, an infrared excess was detected from this system at a wavelength of 60μm.[14] The data suggests a dusty debris disk with a temperature of 45 K is orbiting 211 AU from the host star.[7]


  1. ^ a b c d e van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV data, SIMBAD, Bibcode:1986EgUBV........0M. 
  3. ^ a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819. 
  4. ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048Freely accessible, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, A61. 
  5. ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971Freely accessible, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015. 
  6. ^ a b c d De Rosa, R. J.; et al. (January 2014), "The VAST Survey - III. The multiplicity of A-type stars within 75 pc", Monthly Notices of the Royal Astronomical Society, 437 (2): 1216–1240, arXiv:1311.7141Freely accessible, Bibcode:2014MNRAS.437.1216D, doi:10.1093/mnras/stt1932. 
  7. ^ a b c Rhee, Joseph H.; et al. (May 2007), "Characterization of Dusty Debris Disks: The IRAS and Hipparcos Catalogs", The Astrophysical Journal, 660 (2): 1556–1571, arXiv:astro-ph/0609555Freely accessible, Bibcode:2007ApJ...660.1556R, doi:10.1086/509912. 
  8. ^ a b 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:1208.2037Freely accessible, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x. 
  9. ^ a b Soubiran, C.; et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, arXiv:1004.1069Freely accessible, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247. 
  10. ^ a b Muñoz Bermejo, J.; et al. (May 2013), "A PCA approach to stellar effective temperatures", Astronomy and Astrophysics, 453: A95, arXiv:1303.7218Freely accessible, Bibcode:2013A&A...553A..95M, doi:10.1051/0004-6361/201220961. 
  11. ^ a b Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785Freely accessible, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224. 
  12. ^ "* pi. Ser". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-23. 
  13. ^ Rodriguez, David R.; Zuckerman, B. (February 2012), "Binaries among Debris Disk Stars", The Astrophysical Journal, 745 (2): 147, arXiv:1111.5618Freely accessible, Bibcode:2012ApJ...745..147R, doi:10.1088/0004-637X/745/2/147. 
  14. ^ Cheng, K.-P.; et al. (September 1992), "Newly identified main-sequence A stars with circumstellar dust", Astrophysical Journal, Part 2, 396 (2): L83–L86, Bibcode:1992ApJ...396L..83C, doi:10.1086/186522.