Psi2 Aquarii

ψ² Aquarii
	Location of ψ2 Aquarii (circled)
Observation data; Epoch J2000 Equinox J2000
Constellation	Aquarius
Right ascension	23h 17m 54.21372s
Declination	−09° 10′ 57.0675″
Apparent magnitude (V)	4.403
Characteristics
Spectral type	B5 Vn
U−B color index	−0.561
B−V color index	−0.146
Variable type	λ Eri
Astrometry
Radial velocity (Rv)	−6 km/s
Proper motion (μ)	RA: +17.13 mas/yr ; Dec.: −11.70 mas/yr
Parallax (π)	8.12 ± 0.38 mas
Distance	400 ± 20 ly ; (123 ± 6 pc)
Absolute magnitude (MV)	−1.04
Details
Radius	4.6 R☉
Luminosity	565 L☉
Temperature	15,212 ± 288 K
Rotational velocity (v sin i)	341 km/s
Other designations
	ψ2 Aqr, 93 Aquarii, BD−09°6160, HD 219688, HIP 115033, HR 8858, SAO 146620.
Database references
SIMBAD	data

Psi² Aquarii, Latinized from ψ² Aquarii, is the Bayer designation for a star in the equatorial constellation of Aquarius. It is visible to the naked eye with an apparent visual magnitude of 4.4.^[2] Based upon parallax measurements made during the Hipparcos mission, the distance to this star is roughly 400 light-years (120 parsecs).^[1]

A light curve for Psi² Aquarii, plotted from *TESS* data^[10]

This is a B-type main sequence star with a stellar classification of B5 Vn.^[3] The 'n' suffix indicates that the absorption lines in the spectrum are being broadened by Doppler shift from the star's rapid rotation rate. The projected rotational velocity of the star is 341 km/s.^[8] Psi² Aquarii is 4.6^[7] times as large as the Sun with an effective temperature of 15,212 K^[7] in its outer envelope.

It is a λ Eridani variable, or periodic Be star, with a pulsation cycle lasting 1.073 days.^[4] The amplitude of the variation is 0.024 in magnitude.^[11]

References

^ ^a ^b ^c ^d ^e ^f van Leeuwen, F. (November 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 Kozok, J. R. (September 1985), "Photometric observations of emission B-stars in the southern Milky Way", Astronomy and Astrophysics Supplement Series, 61: 387–405, Bibcode:1985A&AS...61..387K.
^ ^a ^b Lesh, Janet Rountree (December 1968), "The Kinematics of the Gould Belt: an Expanding Group?", Astrophysical Journal Supplement, 17: 371, Bibcode:1968ApJS...17..371L, doi:10.1086/190179.
^ ^a ^b Balona, L. A. (December 1995), "Tests of the Pulsation and Starspot Models for the Periodic Be-Stars", Monthly Notices of the Royal Astronomical Society, 277 (4): 1547, Bibcode:1995MNRAS.277.1547B, doi:10.1093/mnras/277.4.1547.
^ Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
^ ^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.
^ ^a ^b ^c ^d Underhill, A. B.; et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", Monthly Notices of the Royal Astronomical Society, 189 (3): 601–605, Bibcode:1979MNRAS.189..601U, doi:10.1093/mnras/189.3.601.
^ ^a ^b 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.
^ "* 93 Aqr", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2012-07-06.
^ MAST: Barbara A. Mikulski Archive for Space Telescopes, Space Telescope Science Institute, retrieved 10 November 2022.
^ Balona, L. A. (July 1990), "Short-period variability in Be stars", Monthly Notices of the Royal Astronomical Society, 245: 92–100, Bibcode:1990MNRAS.245...92B, doi:10.1093/mnras/245.1.92.

External links

Image Psi2 Aquarii

[aaa474_2_653-1] ^ ^a ^b ^c ^d ^e ^f van Leeuwen, F. (November 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.

[aass61_387-2] Kozok, J. R. (September 1985), "Photometric observations of emission B-stars in the southern Milky Way", Astronomy and Astrophysics Supplement Series, 61: 387–405, Bibcode:1985A&AS...61..387K.

[apjs17_371-3] Lesh, Janet Rountree (December 1968), "The Kinematics of the Gould Belt: an Expanding Group?", Astrophysical Journal Supplement, 17: 371, Bibcode:1968ApJS...17..371L, doi:10.1086/190179.

[mnras277_4_1547-4] Balona, L. A. (December 1995), "Tests of the Pulsation and Starspot Models for the Periodic Be-Stars", Monthly Notices of the Royal Astronomical Society, 277 (4): 1547, Bibcode:1995MNRAS.277.1547B, doi:10.1093/mnras/277.4.1547.

[gcsrv-5] Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.

[Anderson2012-6] 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.

[mnras189_601-7] Underhill, A. B.; et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", Monthly Notices of the Royal Astronomical Society, 189 (3): 601–605, Bibcode:1979MNRAS.189..601U, doi:10.1093/mnras/189.3.601.

[coapa239_1-8] 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-9] "* 93 Aqr", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2012-07-06.

[MAST-10] MAST: Barbara A. Mikulski Archive for Space Telescopes, Space Telescope Science Institute, retrieved 10 November 2022.

[mnras245_92-11] Balona, L. A. (July 1990), "Short-period variability in Be stars", Monthly Notices of the Royal Astronomical Society, 245: 92–100, Bibcode:1990MNRAS.245...92B, doi:10.1093/mnras/245.1.92.

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Psi2 Aquarii

References

External links

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