Pi6 Orionis

Pi⁶ Orionis
	Location of π6 Orionis (circled)
Observation data; Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Orion
Right ascension	04h 58m 32.90210s
Declination	+01° 42′ 50.4582″
Apparent magnitude (V)	4.469
Characteristics
Spectral type	K0/1 III
U−B color index	+1.506
B−V color index	+1.390
Astrometry
Radial velocity (Rv)	+15.36±0.24 km/s
Proper motion (μ)	RA: −1.30 mas/yr ; Dec.: −7.67 mas/yr
Parallax (π)	3.45 ± 0.30 mas
Distance	950 ± 80 ly ; (290 ± 30 pc)
Absolute magnitude (MV)	−2.86
Details
Mass	4.15±0.68 M☉
Radius	87.73±9.79 R☉
Luminosity	2,185.6±418.7 L☉
Surface gravity (log g)	1.20±0.15 cgs
Temperature	4,217±121 K
Metallicity [Fe/H]	−0.23±0.10 dex
Rotational velocity (v sin i)	8 km/s
Age	230±11 Myr
Other designations
	π6 Ori, 10 Orionis, BD+01°872, HD 31767, HIP 23123, HR 1601, SAO 112281
Database references
SIMBAD	data

Pi⁶ Orionis (π⁶ Ori, π⁶ Orionis) is a solitary^[9] star in the eastern part of the constellation Orion. It is visible to the naked eye with an apparent visual magnitude of 4.469.^[2] Based upon an annual parallax shift of 3.45 mas,^[1] it is around 950 light-years from the Sun. At that distance, the visual magnitude of the star is reduced by an interstellar absorption factor of 0.52.^[4]

This is an evolved K-type giant star on the horizontal branch,^[6] with a stellar classification of K0/1 III.^[3] It is a suspected variable star with a measured variation between 4.45 and 4.49 in visual magnitude.^[10] Pi⁶ Orionis has over four times the mass of the Sun and has expanded to around 88 times the Sun's radius. Over the course of its life span, the star has shed around 0.04±0.01 solar mass. With an effective temperature of 4,217 K in its outer atmosphere it is radiating roughly 2,200 times the solar luminosity.^[6]

References

^ ^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.
^ ^a ^b ^c ^d Cousins, A. W. J. (1984), "Standardization of Broadband Photometry of Equatorial Standards", South African Astronomical Observatory Circulars, 8: 59, Bibcode:1984SAAOC...8...59C.
^ ^a ^b Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
^ ^a ^b Famaey, B.; et al. (2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430: 165, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272, S2CID 17804304.
^ Cardini, D. (January 2005), "Mg II chromospheric radiative loss rates in cool active and quiet stars", Astronomy and Astrophysics, 430: 303–311, arXiv:astro-ph/0409683, Bibcode:2005A&A...430..303C, doi:10.1051/0004-6361:20041440, S2CID 12136256.
^ ^a ^b ^c Reffert, Sabine; et al. (2015), "Precise radial velocities of giant stars. VII. Occurrence rate of giant extrasolar planets as a function of mass and metallicity", Astronomy and Astrophysics, 574A (2): 116–129, arXiv:1412.4634, Bibcode:2015A&A...574A.116R, doi:10.1051/0004-6361/201322360, hdl:10722/215277, S2CID 59334290.
^ Bernacca, P. L.; Perinotto, M. (1970), "A catalogue of stellar rotational velocities", Contributi Osservatorio Astronomico di Padova in Asiago, 239 (1): 1, Bibcode:1970CoAsi.239....1B.
^ "pi.06 Ori". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-11-22.
^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
^ Kukarkin, B. V.; et al. (1981), "Catalogue of suspected variable stars", Nachrichtenblatt der Vereinigung der Sternfreunde E.V., Bibcode:1981NVS...C......0K.

[vanLeeuwen2007-1] ^ ^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.

[Cousins1984-2] Cousins, A. W. J. (1984), "Standardization of Broadband Photometry of Equatorial Standards", South African Astronomical Observatory Circulars, 8: 59, Bibcode:1984SAAOC...8...59C.

[Houk1999-3] Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.

[famaey2005-4] Famaey, B.; et al. (2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430: 165, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272, S2CID 17804304.

[Cardini2005-5] Cardini, D. (January 2005), "Mg II chromospheric radiative loss rates in cool active and quiet stars", Astronomy and Astrophysics, 430: 303–311, arXiv:astro-ph/0409683, Bibcode:2005A&A...430..303C, doi:10.1051/0004-6361:20041440, S2CID 12136256.

[Reffert2015-6] Reffert, Sabine; et al. (2015), "Precise radial velocities of giant stars. VII. Occurrence rate of giant extrasolar planets as a function of mass and metallicity", Astronomy and Astrophysics, 574A (2): 116–129, arXiv:1412.4634, Bibcode:2015A&A...574A.116R, doi:10.1051/0004-6361/201322360, hdl:10722/215277, S2CID 59334290.

[Bernacca1970-7] Bernacca, P. L.; Perinotto, M. (1970), "A catalogue of stellar rotational velocities", Contributi Osservatorio Astronomico di Padova in Asiago, 239 (1): 1, Bibcode:1970CoAsi.239....1B.

[SIMBAD-8] "pi.06 Ori". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-11-22.

[Eggleton2008-9] Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.

[csvs-10] Kukarkin, B. V.; et al. (1981), "Catalogue of suspected variable stars", Nachrichtenblatt der Vereinigung der Sternfreunde E.V., Bibcode:1981NVS...C......0K.

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Pi6 Orionis

References

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