HD 172991

Last updated
HD 172991/172992
Corona Australis constellation map.svg
Red circle.svg
Location of HD 172991 (circled)
Observation data
Epoch J2000.0        Equinox J2000.0 (ICRS)
Constellation Corona Australis
Right ascension 18h 44m 57.15228s [1]
Declination −39° 41′ 10.2781″ [1]
Apparent magnitude  (V)5.44±0.01 [2]
Characteristics
A
Spectral type K1/2III [3]
B−V color index +0.87 [4]
B
Spectral type B9/A1V [3]
Astrometry
Radial velocity (Rv)−17.4±0.8 [5]  km/s
Proper motion (μ)RA: +9.815  mas/yr [1]
Dec.: −6.261  mas/yr [1]
Parallax (π)2.6806 ± 0.1453  mas [1]
Distance 1,220 ± 70  ly
(370 ± 20  pc)
Absolute magnitude  (MV)−2.56 [6]
Details
A
Mass 4.98±0.05 [7]   M☉
Radius 53.9±3.0 [8]   R☉
Luminosity 1,750+188
−154 [1]   L☉
Surface gravity (log g)1.03 [9]   cgs
Temperature 4,990±123 [10]   K
Metallicity [Fe/H]−0.41 [9]   dex
Rotational velocity (v sin i)3.9±2 [11]  km/s
Other designations
20 G. Coronae Australis [12] , CD−39°12864, CPD−39°8163, GC  25628, HD  172991, 172992, HIP  91989, HR  7031, SAO  210518 [13]
Database references
SIMBAD data

HD 172991, also known as HR 7031 or rarely 20 G. Coronae Australis, is a binary star [14] located in the southern constellation Corona Australis. It has a combined apparent magnitude of 5.44, [2] making it faintly visible to the naked eye. The system is located relatively far at a distance of 1,220 light years based on Gaia DR3 parallax measurements [1] but is receding with a heliocentric radial velocity of −17.4  km/s . [5] At its current distance HD 172991's brightness is diminished by magnitudes due to interstellar dust and it has an absolute magnitude of −2.56. [6]

HD 172991 has a stellar classification of K1/2 III, [3] indicating that it is an evolved red giant. The companion, HD 172992, is a B-type star with a stellar classification of B9/A1 V. [3] Although the two components can be resolved in the spectrum, they cannot be observed in telescopes, making observation difficult. [15]

HD 172991 has 4.98 times the mass of the Sun [7] but it has expanded to 53.9 times the Sun's radius. [8] It radiates 1,750 times the luminosity of the Sun [1] from its enlarged photosphere at an effective temperature of 4,990  K , [10] giving it a yellowish-orange hue. It is metal deficient with an iron abundance 39% of the Sun's ([Fe/H] = −0.41) [9] and spins modestly with a projected rotational velocity of 3.9  km/s . [11]

Related Research Articles

HD 164712, also known as HR 6731 is an orange hued star located in the southern constellation of Apus. It has an apparent magnitude of 5.86, making it faintly visible to the naked eye if viewed under ideal conditons. Parallax measurements place the object at a distance of 229 light-years (70 pc), and it is currently receding with a heliocentric radial velocity of 14.8 km/s.

HD 173791 is a solitary yellow hued star located in the southern constellation Telescopium. It has an apparent magnitude of 5.80, allowing it to be viewed with the naked eye under suitable viewing conditions. Parallax measurements place the object at a distance of 364 light years, and it is currently receding from the Solar System with a heliocentric radial velocity of 9.7 km/s.

<span class="mw-page-title-main">HD 24479</span> Star in the constellation Camelopardalis

HD 24479, also designated as HR 1204, is a solitary, bluish-white hued star located in the northern circumpolar constellation Camelopardalis. The star is visible to the naked eye with an apparent visual magnitude of 5.04. Based on Gaia DR3 parallax measurements, it is located 385 light years from the Sun. However, it is receding with a somewhat constrained heliocentric radial velocity of 4.6 km/s. At its current distance, HD 24479's brightness is diminished by 0.29 magnitudes due to interstellar dust.

HD 96146 is a binary star located in the southern constellation Antlia. The system has a combined apparent magnitude of 5.41, making it visible to the naked eye under ideal conditions. Parallax measurements from the Gaia spacecraft place the pair at a distance of 710 light years with a large margin of error. It is currently receding with a poorly constrained heliocentric radial velocity of 4.7 km/s.

HD 126209, also known as HR 5389, is a solitary, orange hued star located in the southern circumpolar constellation Apus. It has an apparent magnitude of 6.06, making it faintly visible to the naked eye under ideal conditions. Based on parallax measurements from the Gaia spacecraft, the object is estimated to be 560 light years distant. It appears to be approaching the Solar System with a fairly constrained heliocentric radial velocity of −8.1 km/s. De Mederios et al. (2014) found the radial velocity to be variable, making it a probable spectroscopic binary. Eggen (1993) lists it as a member of the old disk population.

<span class="mw-page-title-main">HD 154556</span> High proper motion star; K-type subgiant

HD 154556, also known as HR 6357, is a solitary orange-hued star located in the southern circumpolar constellation Apus. It has an apparent magnitude of 6.21, placing it near the limit for naked eye visibility. The star is located relatively close at a distance of 228 light years based on Gaia DR3 parallax measurements, but it is drifter closer with a heliocentric radial velocity of −24 km/s. At its current distance, HD 154556's brightness is diminished by 0.26 magnitudes due to interstellar dust. It has an absolute magnitude of +2.10.

HD 39901 is an orange hued star located in the constellation Columba. It is also called HR 2069, which is the star's Bright Star Catalog designation. Eggen (1989) lists it as a member of the old disk population.

<span class="mw-page-title-main">HD 57197</span> Star in the constellation Puppis

HD 57197, also known as M Puppis or HR 2789, is a suspected astrometric binary located in the southern constellation Puppis, the poop deck. It has an apparent magnitude of 5.84, making it faintly visible to the naked eye under ideal conditions. Based on parallax measurements from the Gaia satellite, the system is estimated to be 629 light years away from the Solar System. The value is poorly constrained, but it appears to be receding with a heliocentric radial velocity of 13 km/s. At its current distance, HD 57197's brightness is diminished by 0.3 magnitudes due to interstellar dust. It has an absolute magnitude of -0.43.

HD 47475 is a solitary star located in the southern constellation Columba. With an apparent magnitude of 6.34, its barely visible to the naked eye under ideal conditions. The star is located 1,720 light years away from the Solar System, but is drifting away with a heliocentric radial velocity of 15.77 km/s.

<span class="mw-page-title-main">HD 76236</span> Star in the constellation Chamaeleon

HD 76236, also designated as HR 3543 or rarely 11 G. Chamaeleontis, is a solitary star located in the southern circumpolar constellation Chamaeleon. It is faintly visible to the naked eye as an orange-hued star with an apparent magnitude of 5.77. Based on parallax measurements from the Gaia satellite, the object is estimated to be 612 light years away. Currently, it is receding with a heliocentric radial velocity of 7 km/s. At its current distance, HD 76236's brightness is diminished by 0.39 magnitudes due to interstellar dust. It has an absolute magnitude of −0.13.

<span class="mw-page-title-main">HD 114533</span> Star in the constellation Chamaeleon

HD 114533, also known as HR 4976, is a solitary star located in the southern circumpolar constellation Chamaeleon. It has an apparent magnitude of 5.84, making it faintly visible to the naked eye. The system is located relatively far at a distance of roughly 2,100 light years based on Gaia DR3 parallax measurements but is drifting closer with a heliocentric radial velocity of −18 km/s. At its current distance, HD 114533A's brightness is diminished by 0.74 magnitudes due to interstellar dust. It has an absolute magnitude of −2.0.

HD 33519, also known as HR 1682, is a probable spectroscopic binary located in the southern circumpolar constellation Mensa. It is one of the stars near the limit of naked eye visibility, having an apparent magnitude of 6.28. The system is relatively far at a distance of 940 light years but is approaching with a heliocentric radial velocity of −2.5 km/s. However, this value is poorly constrained.

HD 31529, also known as HR 1584, is a solitary, orange hued star located in the southern constellation Caelum, the chisel. It has an apparent magnitude of 6.09, making it faintly visible to the naked eye if viewed under ideal conditions. This object is located relatively far at a distance of 932 light years based on parallax measurements from Gaia DR3, but is receding with a heliocentric radial velocity of 28.4 km/s. Eggen (1989) lists it as a member of the old disk population.

<span class="mw-page-title-main">HD 198716</span> Star in the constellation of Microscopium

HD 198716, also known as HR 7987 or 33 G. Microscopii, is a solitary star located in the southern constellation Microscopium. Eggen (1993) lists it as a member of the Milky Way's old disk population.

<span class="mw-page-title-main">HD 168592</span> Star in the constellation of Corona Australis

HD 168592, also designated as HR 6862 or rarely 7 G. Coronae Australis, is a solitary star located in the southern constellation Corona Australis. It is faintly visible to the naked eye as an orange-hued star with an apparent magnitude of 5.07. Gaia DR3 parallax measurements place it at a distance of 490 light years and is currently receding with a heliocentric radial velocity of 18 km/s. At its current distance, HD 168592's brightness is diminished by 0.38 magnitudes due to interstellar dust. It has an absolute magnitude of −0.76.

<span class="mw-page-title-main">HD 31134</span> Star in the constellation of Camelopardalis

HD 31134, also designated as HR 1561, is a solitary star located in the northern circumpolar constellation Camelopardalis, the giraffe. It is faintly visible to the naked eye as a white-hued star with an apparent magnitude of 5.74. Gaia DR3 parallax measurements place it 473 light years away. It appears to be approaching the Solar System with a heliocentric radial velocity of −15.1 km/s. At its current distance, HD 31134's brightness is diminished by 0.35 magnitudes due to interstellar dust. It has an absolute magnitude of +0.19.

<span class="mw-page-title-main">HD 101917</span> High proper motion star

HD 101917, also designated as HR 4509, or rarely 34 G. Chamaeleontis, is a solitary star located in the southern circumpolar constellation Chamaeleon. It has an apparent magnitude of 6.38, placing it near the limit for naked eye visibility. The object is located relatively close at a distance of 185 light years based on Gaia DR3 parallax measurements but is receding with a heliocentric radial velocity of 33 km/s. At its current distance, HD 101917's brightness is diminished by 0.28 magnitudes due to interstellar dust. It has an absolute magnitude of +2.69.

<span class="mw-page-title-main">HD 174500</span> Star in the constellation of Telescopium

HD 174500, also designated as HR 7097 or rarely 34 G. Telescopii, is a solitary white-hued star located in the southern constellation Telescopium. It has an apparent magnitude of 6.16, placing it near the limit for naked eye visibility. Gaia DR3 parallax measurements place the object 692 light years away, and it is currently receding with a heliocentric radial velocity of 35 km/s. At its current distance, HD 174500's brightness is diminished by 0.39 magnitudes due to interstellar dust. It has an absolute magnitude of −0.82.

<span class="mw-page-title-main">HD 189080</span> High proper motion star; K-type star

HD 189080, also known as HR 7621 or rarely 74 G. Telescopii, is a solitary orange-hued star located in the southern constellation Telescopium. It has an apparent magnitude of 6.18, placing it near the limit for naked eye visibility. Gaia DR3 parallax measurements place it at a distance of 357 light years and it is currently receding rapidly with a heliocentric radial velocity of 66.9 km/s. At its current distance, HD 189080's brightness is diminished by 0.17 magnitudes due to extinction from interstellar dust. It has an absolute magnitude of +1.1.

<span class="mw-page-title-main">HD 170873</span> K-type giant; Telescopium

HD 170873, also known as HR 6954 or rarely 19 G. Telescopii, is a solitary orange-hued star located in the southern constellation Telescopium. It has an apparent magnitude of 6.20, placing it near the limit for naked eye visibility. Gaia DR3 parallax measurements imply a distance of 551 light years and it is currently receding with a heliocentric radial velocity of 23.8 km/s. At its current distance, HD 170873's brightness is diminished by 0.39 magnitudes due to interstellar dust, and it has an absolute magnitude of −0.31.

References

  1. 1 2 3 4 5 6 7 8 Vallenari, A.; et al. (Gaia Collaboration) (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics . arXiv: 2208.00211 . doi: 10.1051/0004-6361/202243940 . Gaia DR3 record for this source at VizieR.
  2. 1 2 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN   0004-6361. S2CID   17128864.
  3. 1 2 3 4 Houk, N. (1982). Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. Volume_3. Declinations -40_ƒ0 to -26_ƒ0. Bibcode:1982mcts.book.....H.
  4. ↑ Corben, P. M.; Stoy, R. H. (1968). "Photoelectric Magnitudes and Colours for Bright Southern Stars". Monthly Notes of the Astronomical Society of South Africa. 27: 11. Bibcode:1968MNSSA..27...11C. ISSN   0024-8266.
  5. 1 2 Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35,495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv: 1606.08053 . Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN   1562-6873. ISSN   1063-7737. S2CID   119231169.
  6. 1 2 Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv: 1108.4971 . Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN   1562-6873. ISSN   1063-7737. S2CID   119257644.
  7. 1 2 Hohle, M.M.; Neuhäuser, R.; Schutz, B.F. (April 2010). "Masses and luminosities of O- and B-type stars and red supergiants". Astronomische Nachrichten. 331 (4): 349–360. arXiv: 1003.2335 . Bibcode:2010AN....331..349H. doi:10.1002/asna.200911355. eISSN   1521-3994. ISSN   0004-6337. S2CID   111387483.
  8. 1 2 Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants. Surface brightness relations calibrated by interferometry". Astronomy & Astrophysics. 426 (1): 297–307. arXiv: astro-ph/0404180 . Bibcode:2004A&A...426..297K. doi: 10.1051/0004-6361:20035930 . eISSN   1432-0746. ISSN   0004-6361. S2CID   6077801.
  9. 1 2 3 Anders, F.; et al. (August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy & Astrophysics. 628: A94. arXiv: 1904.11302 . Bibcode:2019A&A...628A..94A. doi: 10.1051/0004-6361/201935765 . eISSN   1432-0746. ISSN   0004-6361. S2CID   131780028.
  10. 1 2 Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv: 1905.10694 . Bibcode:2019AJ....158..138S. doi: 10.3847/1538-3881/ab3467 . eISSN   1538-3881. hdl: 1721.1/124721 . S2CID   166227927.
  11. 1 2 De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (January 2014). "A catalog of rotational and radial velocities for evolved stars V: Southern stars *". Astronomy & Astrophysics. 561: A126. arXiv: 1312.3474 . Bibcode:2014A&A...561A.126D. doi: 10.1051/0004-6361/201220762 . eISSN   1432-0746. ISSN   0004-6361. S2CID   54046583.
  12. ↑ Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
  13. ↑ "HD 172991". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved March 16, 2023.
  14. ↑ Eggleton, P. P.; Tokovinin, A. A. (11 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 . eISSN   1365-2966. ISSN   0035-8711. S2CID   14878976.
  15. ↑ Bonneau, D.; Blazit, A.; Foy, R.; Labeyrie, A. (November 1980). "Speckle interferometric measurements of binary stars". Astronomy and Astrophysics Supplement Series. 42: 185–188. Bibcode:1980A&AS...42..185B. ISSN   0365-0138.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.