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HR 8832

Star HB 8822 (circled) lies just off the "W" shape of the constellation Cassiopeia.
Observation data Epoch J2000      Equinox J2000
Constellation	Cassiopeia
Right ascension	23 13 16.97632
Declination	+57° 10′ 06.0823″
Apparent magnitude (V)	5.574
Characteristics
Spectral type	K3 V
U−B color index	+0.902
B−V color index	+0.983
Variable type	Suspected
Astrometry
Radial velocity (Rv)	–18.5 km/s
Proper motion (μ)	RA: +2075.07±0.33 mas/yr Dec.: +295.45±0.25 mas/yr
Parallax (π)	152.76 ± 0.29 mas
Distance	21.35 ± 0.04 ly (6.55 ± 0.01 pc)
Absolute magnitude (MV)	6.50
Details
Mass	0.794+0.037 −0.022 M☉
Radius	0.80±0.04 R☉
Luminosity	0.28 L☉
Surface gravity (log g)	4.50 cgs
Temperature	4710 K
Metallicity	+0.20 dex
Rotational velocity (v sin i)	6.94 km/s
Age	~12.46 Gyr
Other designations
BD+56 2966, FK5 875, GCTP 5616.00, Gl 892, HD 219134, HIP 114622, LFT 1767, LHS 71, LTT 16826, SAO 35236.

HR 8832 (or HD 219134, or Gliese 892) is a main sequence star in the constellation of Cassiopeia. It is smaller and less luminous than our Sun, with a spectral class of K3V, which makes it an orange-red hued star. HR 8832 is relatively close to our system, with an estimated distance of 21.25 light years. This star is close to the limit of apparent magnitude that can still be seen by the unaided eye. The limit is considered to be magnitude 6 for most observers.

This star has a magnitude 9.4 companion at an angular separation of 106.6 arcseconds. The star is reported to host a rocky super-Earth, HD 219134 b, based on size (1.6 times the size of Earth), and density (6 grams per cubic cm). A further three exoplanets, two super-Earths and one Jovian world, have been deduced using Harps-N radial velocity data.

Planetary system

Distance

Template:Πt Template:Πp Template:Πp Template:Πp Template:Πp Template:Πp Template:Πp Template:Πp Template:Πe

References

1. ^ 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.
2. ^ Oja, T. (August 1986), "UBV photometry of stars whose positions are accurately known. III", Astronomy and Astrophysics Supplement Series, 65 (2): 405–409, Bibcode:1986A&AS...65..405O.
3. ^ Frasca, A.; et al. (December 2009), "REM near-IR and optical photometric monitoring of pre-main sequence stars in Orion. Rotation periods and starspot parameters", Astronomy and Astrophysics, 508 (3): 1313–1330, Bibcode:2009A&A...508.1313F, doi:10.1051/0004-6361/200913327.
4. Kukarkin, B. V.; et al. (1981), "Nachrichtenblatt der Vereinigung der Sternfreunde e.V. (Catalogue of suspected variable stars)", Nachrichtenblatt der Vereinigung der Sternfreunde e.V. (1981), Moscow: Academy of Sciences USSR Shternberg: 0, Bibcode:1981NVS...C......0K.
5. Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veröff. Astron. Rechen-Inst. Heidelb, 35 (35), Astronomisches Rechen-Institut Heidelberg: 1, Bibcode:1999VeARI..35....1W.
6. ^ Takeda, Genya; et al. (February 2007), "Structure and Evolution of Nearby Stars with Planets. II. Physical Properties of ~1000 Cool Stars from the SPOCS Catalog", The Astrophysical Journal Supplement Series, 168 (2): 297–318, arXiv:astro-ph/0607235, Bibcode:2007ApJS..168..297T, doi:10.1086/509763.
7. Perrin, M.-N.; Karoji, H. (1987), "Stellar radius determination from IRAS 12-micron fluxes", Astronomy and Astrophysics, 172: 235–240, Bibcode:1987A&A...172..235P.
8. Martínez-Arnáiz, R.; et al. (September 2010), "Chromospheric activity and rotation of FGK stars in the solar vicinity. An estimation of the radial velocity jitter", Astronomy and Astrophysics, 520: A79, arXiv:1002.4391, Bibcode:2010A&A...520A..79M, doi:10.1051/0004-6361/200913725.
9. "HR 8832 -- Flare Star", SIMBAD Astronomical Object Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-04-08.
10. 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.{{citation}}: CS1 maint: unflagged free DOI (link)
11. "PIA19832: Location of Nearest Rocky Exoplanet Known". NASA. 30 July 2015. Retrieved 30 July 2015.
12. Chou, Felicia; Clavin, Whitney (30 July 2015). "NASA's Spitzer Confirms Closest Rocky Exoplanet". NASA. Retrieved 31 July 2015.
13. "Cassiopeia's Hidden Gem". Harvard. 30 July 2015. Retrieved 30 July 2015.
14. Cite error: The named reference release was invoked but never defined (see the help page).

Notes

1. From ${\displaystyle {\begin{smallmatrix}L=4\pi R^{2}\sigma T_{\rm {eff}}^{4}\end{smallmatrix}}}$, where ${\displaystyle {\begin{smallmatrix}L\end{smallmatrix}}}$ is the luminosity, ${\displaystyle {\begin{smallmatrix}R\end{smallmatrix}}}$ is the radius, ${\displaystyle {\begin{smallmatrix}T_{\rm {eff}}\end{smallmatrix}}}$ is the effective surface temperature and ${\displaystyle {\begin{smallmatrix}\sigma \end{smallmatrix}}}$ is the Stefan–Boltzmann constant

External links

• "BD+56 2966 / HR 8832". SolStation. Retrieved November 7, 2005.

v t e Constellation of Cassiopeia
List of stars in Cassiopeia Cassiopeia in Chinese astronomy
Stars	Bayer α (Schedar) β (Caph) γ (Navi/Tsih) δ (Ruchbah) ε (Segin) ζ (Fulu) η (Achird) θ (Marfak) ι κ λ μ ν ξ ο π ρ σ τ υ υ (Castula) φ χ ψ ω Flamsteed 1 2 4 6 9 10 12 42 47 48 (A) 49 50 54 Variable R S TZ WZ YZ (21) AO AR PZ V373 V509 V547 V669 V705 V762 V863 V773 V987 V1022 V1405 HR 5 91 144 196 244 273 297 743 932 8832 8853 8881 HD 861 7924 7977 15558 17156 (Nushagak) 240210 240237 240429 240430 Other BD+60°2522 Gliese 49 IRAS 23304+6147 LS I +61 303 PSR J0205+6449 Tycho G 4U 0142+61 WR 2 WR 3
Exoplanets HD 7924 b HD 17156 b HD 219134 b c d e (h) f g HD 240210 b HD 240237 b
Star clusters Messier 52 Messier 103 NGC 103 NGC 110 NGC 129 NGC 133 NGC 136 NGC 146 NGC 189 NGC 225 NGC 358 NGC 366 NGC 381 NGC 433 NGC 436 NGC 457 NGC 559 NGC 637 NGC 654 NGC 659 NGC 663 NGC 1027 NGC 7789 NGC 7790 Trumpler 3
Nebulae	NGC 281 7635 Other 3C 58 Cassiopeia A Heart Nebula IC 289 IC 1805 KjPn 8 LBN 114.55+00.22 Sh 2-185 Westerhout 5
Galaxies	NGC 147 185 278 Other Andromeda VII 3C 20 3C 35 Dwingeloo 1 Dwingeloo 2 MB 3 IC 10 Maffei 1 Maffei 2 QSO B0153+744
Astronomical events SN 1181 SN 1572 (B)
Category

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