Upsilon Capricorni

Star in the constellation Capricornus

Upsilon Capricorni

Location of υ Capricorni (circled)

Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation | Capricornus
Right ascension | 20h 40m 02.94518s[1]
Declination | −18° 08′ 19.1664″[1]
Apparent magnitude (V) | 5.17[2]
Characteristics
Spectral type | M1 III[3]
B−V color index | +1.65[2]
Astrometry
Radial velocity (Rv)| −12.3±1.6[4] km/s
Proper motion (μ)|  RA: −22.764 mas/yr[5]
Dec.: −22.170 mas/yr[5]
Parallax (π)| 5.1719±0.1354 mas[5]
Distance| 630 ± 20 ly
(193 ± 5 pc)
Absolute magnitude (MV)| −1.09[6]
Details
Radius| 92±4[7] R☉
Luminosity| 1,283.0±76.5[1] L☉
Temperature| 3,953+427
−193[1] K
Metallicity [Fe/H]| −0.08[6] dex
Other designations
υ Cap, 15 Capricorni, NSV 25208, BD−18°5738, FK5 773, HD 196777, HIP 101984, HR 7900, SAO 163779[8]
Database references
SIMBAD| data

Upsilon Capricorni, Latinized from υ Capricorni, is a solitary[9] star in the southern constellation of Capricornus. It has a reddish hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.17.[2] The star is about 630 light years away based on parallax,[5] but is drifting closer with a radial velocity of −12 km/s.[4] It is 0.22 degree north of the ecliptic, so is subject to lunar occultations.[10][11]

This is an aging red giant star on the asymptotic giant branch[12] with a stellar classification of M1 III,[3] a star that has exhausted the supply of hydrogen at its core then cooled and expanded. It has 92 times the radius of the Sun[7] and is radiating 1,283 times the luminosity of the Sun[1] from its swollen photosphere at an effective temperature of 3,953 K.[1]

It is a suspected variable star of unknown type with a brightness that has been measured ranging from a peak of 5.19 down to 5.24.[13]

## References

[edit]

1. ^ a b c d e f 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.
2. ^ a b c Barnes, T. G.; et al. (May 1978), "Stellar angular diameters and visual surface brightness. III - an improved definition of the relationship", Monthly Notices of the Royal Astronomical Society, 183 (3): 285–304, Bibcode:1978MNRAS.183..285B, doi:10.1093/mnras/183.3.285.
3. ^ a b Houk, N.; Smith-Moore, M. (1988), Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars, vol. 4, Bibcode:1988mcts.book.....H.
4. ^ a b 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.
5. ^ a b c Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
6. ^ 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.
7. ^ a b Baines, Ellyn K.; Clark, James H.; Kingsley, Bradley I.; Schmitt, Henrique R.; Stone, Jordan M. (2025-05-07), "Vintage NPOI: New and Updated Angular Diameters for 145 Stars", The Astronomical Journal, 169 (6): 293, arXiv:2506.02912, Bibcode:2025AJ....169..293B, doi:10.3847/1538-3881/adc930, ISSN 1538-3881
8. ^ "* ups Cap". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-05-12.
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.
10. ^ White, Nathaniel M.; Feierman, Barry H. (September 1987), "A Catalog of Stellar Angular Diameters Measured by Lunar Occultation", Astronomical Journal, 94: 751, Bibcode:1987AJ.....94..751W, doi:10.1086/114513.
11. ^ Dunham, D. W.; Evans, D. S.; Silverberg, E. C.; Wiant, J. R. (March 1973), "The angular diameter of Upsilon Capricorni and an occultation of SAO 118655.", Astronomical Journal, 78: 199–201, Bibcode:1973AJ.....78..199D, doi:10.1086/111398.
12. ^ Eggen, Olin J. (July 1992), "Asymptotic giant branch stars near the sun", Astronomical Journal, 104 (1): 275–313, Bibcode:1992AJ....104..275E, doi:10.1086/116239.
13. ^ Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.

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* t
* e

Constellation of Capricornus

* Capricornus in Chinese astronomy
* List of stars in Capricornus

Stars|

| Bayer|

* α1 (Prima Giedi)
* α2 (Algedi)
* β1 (Dabih)
* β2
* γ (Nashira)
* δ (Deneb Algedi)
* ε
* ζ
* η
* θ
* ι
* κ
* λ
* μ
* ν (Alshat)
* ξ1
* ξ2
* ο1
* ο2
* π
* ρ
* σ
* τ1
* τ2
* υ
* φ
* χ
* ψ
* ω

|

Flamsteed|

* 3
* 4
* 17
* 19
* 20
* 21
* 24 (A)
* 27
* 29
* 30
* 31
* 33
* 35
* 36 (b)
* 37
* 41
* 42
* 44
* 45
* 46 (c)
* 47 (c2)
* 50

Variable|

* R
* BB

HR|

* 7722
* 7845
* 7898

HD|

* 197027
* 202206
* 204313
* 206893

Other|

* HATS-3
* LP 816-60

| Exoplanets|

* HD 192310 b
* c
* HD 202206 c
* HD 204313 b
* HD 202772 Ab
* PSO J318.5−22

|

| Star clusters|

* Messier 30
* Palomar 12

|

Galaxies|

| NGC|

* 6907
* 7016
* 7019
* 7030
* 7035
* 7035A
* 7073

|

Other|

* IC 1337
* PKS 2126-158
* PKS 2155-152

| Galaxy clusters|

* HCG 87

|

Category
*[RA:]: Right Ascension
*[Dec.:]: Declination
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