R Apodis

Last updated
R Apodis
Observation data
Epoch J2000.0        Equinox J2000.0 (ICRS)
Constellation Apus
Right ascension 14h 57m 52.98352s [1]
Declination −76° 39′ 45.5569″ [1]
Apparent magnitude  (V)5.36±0.01 [2]
Characteristics
Spectral type K4 III: [3]
B−V color index +1.44 [4]
Variable type constant [5]
Astrometry
Radial velocity (Rv)−31.20±0.08 [6]  km/s
Proper motion (μ)RA: −69.161  mas/yr [1]
Dec.: −16.583  mas/yr [1]
Parallax (π)7.8879 ± 0.0867  mas [1]
Distance 413 ± 5  ly
(127 ± 1  pc)
Absolute magnitude  (MV)−0.22±0.16 [7]
Details [6]
Mass 1.10±0.18  M☉
Radius 33.9±0.9 [1]   R☉
Luminosity 293+9
−10 [1]   L☉
Surface gravity (log g)1.99±0.05  cgs
Temperature 4,318±18  K
Metallicity [Fe/H]−0.29±0.05  dex
Rotational velocity (v sin i)2.64±0.45 km/s
Age 5.68±2.42  Gyr
Other designations
18 G. Apodis [8] , R Aps, CD−76°688, CPD−76°924, FK5  3175, GC  20057, HD  131109, HIP  73223, HR  5540, SAO  257212
Database references
SIMBAD data

R Apodis (HD 131109; HR 5540; 18 G. Apodis) is a solitary star [9] in the constellation Apus. It is faintly visible to the naked eye as an orange-hued point of light with an apparent magnitude of 5.36. [2] Parallax measurements imply a distance of 413 light-years [1] and it is drifting closer with a heliocentric radial velocity of −31.2  km/s . [6] At its current distance, R Apodis' brightness is diminished by an interstellar extinction of 0.26 magnitudes [10] and it has an absolute magnitude of −0.22. [7]

HD 131109 was the first star observed to be variable in the constellation; It was first discovered in 1873 by Benjamin Apthorp Gould. Later, it was hastily given the variable star designation R Apodis in a 1907 variable star catalogue despite it being a suspected variable star at the time. [11] However, observations conducted in a 1952 field star survey revealed that R Apodis was not variable at all. [12] Keenan & Pitts (1980) found that it varied between magnitudes 5.5 and 6.1, but this was never confirmed. [13] Hipparcos photometric data revealed that R Apodis indeed had a constant brightness. [14] It has since been listed as a class CST: in the General Catalog of Variable Stars. [5]

R Apodis has a stellar classification of K4 III:, [3] indicating that it is an evolved K-type giant that has ceased hydrogen fusion at its core and left the main sequence. However, there is uncertainty about the luminosity class. It has a comparable mass to the Sun at 1.1 solar masses but, at the age of 5.68 billion years, it has expanded to 23 times the radius of the Sun. [6] It radiates 293 times the luminosity of the Sun [1] from its enlarged photosphere at an effective temperature of 4,318  K . [6] R Apodis is metal deficient with an iron abundance roughly half of the Sun's [6] and it spins slowly with a projected rotational velocity lower than 1.3  km/s . [15]

Related Research Articles

<span class="mw-page-title-main">Theta Ursae Minoris</span> Suspected binary star in the constellation Ursa Minor

Theta Ursae Minoris, Latinized from θ Ursae Minoris, is a suspected binary star system that is visible to the naked eye in the northern circumpolar constellation of Ursa Minor. It is roughly 860 light years from Earth with an apparent visual magnitude of 5.0. The system is moving closer to the Sun with a radial velocity of −25 km/s.

<span class="mw-page-title-main">Theta Apodis</span> Star in the constellation Apus

Theta Apodis is a variable star in the southern circumpolar constellation of Apus. It is a variable star with an apparent visual magnitude range of 4.65 to 6.20, which, according to the Bortle Dark-Sky Scale, means it is a faint star but visible to the naked eye from dark suburban skies. The distance to Theta Apodis is approximately 350 light-years, based upon parallax measurements made from the Gaia telescope. It is unusual in that it is a red star with a high proper motion.

<span class="mw-page-title-main">V337 Carinae</span> Star in the constellation of Carina

V337 Carinae is a K-type bright giant star in the constellation of Carina. It is an irregular variable and has an apparent visual magnitude which varies between 3.36 and 3.44.

HD 91942 is a single variable star in the constellation Carina. It has the Bayer designation r Carinae, while HD 91942 is the identifier from the Henry Draper catalogue. This orange-hued object is visible to the naked eye with an apparent visual magnitude of 4.45. Based on parallax measurements, it is located at a distance of approximately 1,180 light years from the Sun. The star has an absolute magnitude of −3.77, and is drifting further away with a radial velocity of +9.9 km/s.

<span class="mw-page-title-main">NO Apodis</span> Star in the constellation Apus

NO Apodis is a solitary, red hued variable star located in the southern circumpolar constellation Apus. It has an average apparent magnitude of 5.86, allowing it to be faintly seen with the naked eye. The object is relatively far at a distance of 790 light years but is drifting closer with a heliocentric radial velocity −18.3 km/s.

<span class="mw-page-title-main">28 Monocerotis</span> Star in the constellation Monoceros

28 Monocerotis is a single star in the equatorial constellation of Monoceros. It has an orange-hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.69. The distance to this star is approximately 450 light years based on parallax, and it has an absolute magnitude of −1.00. The star is drifting further away from the Sun with a radial velocity of +26.7 km/s.

<span class="mw-page-title-main">Sigma Ophiuchi</span> Star in the constellation Ophiuchus

Sigma Ophiuchi, Latinized from σ Ophiuchi, is a single, orange-hued star in the equatorial constellation Ophiuchus. Its apparent visual magnitude is 4.31, which is bright enough to be faintly visible to the naked eye. The annual parallax shift of 3.62 mas as seen from Earth provides a distance estimate of roughly 900 light years. It is moving closer to the Sun with a radial velocity of −28 km/s.

<span class="mw-page-title-main">31 Orionis</span> Binary star in the constellation Orion

31 Orionis is a binary star system in the equatorial constellation of Orion, located near the bright star Mintaka. It is visible to the naked eye as a faint, orange-hued point of light with a baseline apparent visual magnitude of 4.71. The distance to this system is approximately 490 light years away based on parallax, and it is drifting further away with a mean radial velocity of +6 km/s.

<span class="mw-page-title-main">17 Persei</span> Star in the constellation Perseus

17 Persei is a single star in the northern constellation of Perseus, located about 420 light years away from the Sun. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.53. This object is moving further from the Earth at a heliocentric radial velocity of +13 km/s.

<span class="mw-page-title-main">30 Piscium</span> Star in the constellation Pisces

30 Piscium is a solitary variable star in the zodiac constellation of Pisces. It is visible to the naked eye with an apparent visual magnitude of 4.37. Its calculated mid-value of antiposed parallax shift as the Earth moves around the Sun of very roughly 7.88 mas, makes it around 410 light years away. Its net movement in the present epoch is one of moving closer – radial velocity is −12 km/s.

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

QZ Puppis is a class B2.5V star in the constellation Puppis. Its apparent magnitude is 4.5 and it is approximately 650 light years away based on parallax.

<span class="mw-page-title-main">ET Virginis</span> Evolved red giant star in the constellation Virgo

ET Virginis is a single, red-hued star in the equatorial constellation of Virgo. It can be viewed with the naked eye, having an apparent visual magnitude of 4.91. Based upon an annual parallax shift of 5.9 mas, it is located 560 light years away. It is moving further from the Earth with a heliocentric radial velocity of +18.6 km/s, having come within 177 ly of the Sun around 6.3 million years ago.

<span class="mw-page-title-main">9 Persei</span> Blue supergiant star in the constellation Perseus

9 Persei is a single variable star in the northern constellation Perseus, located around 4,300 light years away from the Sun. It has the Bayer designation i Persei; 9 Persei is the Flamsteed designation. This body is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of about 5.2. It is moving closer to the Sun with a heliocentric radial velocity of −15.2 km/s. The star is a member of the Perseus OB1 association of co-moving stars.

<span class="mw-page-title-main">HD 42540</span> Star in the constellation Pictor

HD 42540, also known as HR 2196, is a giant star in the constellation Pictor. A class K2-3III orange giant, its apparent magnitude is 5.04 and it is approximately 389 light years away based on parallax.

<span class="mw-page-title-main">Gliese 908</span> Star in the constellation Pisces

Gliese 908 is a red dwarf star, located in constellation Pisces at 19.3 light-years from Earth. It is a BY Draconis variable star with a variable star designation of BR Piscium. Its apparent magnitude varies between magnitude 8.93 and magnitude 9.03 as a result of starspots and varying chromospheric activity.

<span class="mw-page-title-main">S Apodis</span> Variable star in the constellation Apus

S Apodis, also known as HD 133444 is a variable star located in the southern circumpolar constellation Apus. It has an apparent magnitude ranging from 9.6 to 17, which is below the limit for naked eye visibility. The object is located relatively far at a distance of approximately 15,000 light years based on Gaia DR3 parallax measurements, but it is drifting closer with a heliocentric radial velocity of −75 km/s.

<span class="mw-page-title-main">HD 124099</span> Semiregular variable; Apus

HD 124099 is a solitary orange-hued star located in the southern circumpolar constellation Apus. It has an average apparent magnitude of 6.47, placing it very close to the limit for naked eye visibility, even under ideal conditions. The object is located relatively far at a distance of approximately 2,030 light-years based on Gaia DR3 parallax measurements, but it is drifting closer with a heliocentric radial velocity of −10.2 km/s. At its current distance, HD 124099's average brightness is diminished by 0.47 magnitudes due to interstellar extinction and it has an absolute magnitude of −2.10.

<span class="mw-page-title-main">V419 Cephei</span> Star in the constellation Cepheus

V419 Cephei is an irregular variable star in the constellation of Cepheus with an apparent magnitude that varies between 6.54 and 6.89.

HD 222806 is a suspected astrometric binary in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.74, allowing it to be faintly seen with the naked eye. Parallax measurements place the system at a distance of 565 light years and it is currently receding with a heliocentric radial velocity of 21 km/s.

<span class="mw-page-title-main">Lambda Doradus</span> Star in the constellation of Dorado

Lambda Doradus, Latinized from λ Doradus, is a solitary yellow hued star located in the southern constellation Dorado. It has an apparent magnitude of 5.13, making it faintly visible to the naked eye if viewed under ideal conditions. Parallax measurements place the star at a distance of 551 light years, and it is currently receding with a heliocentric radial velocity of 10 km/s.

References

  1. 1 2 3 4 5 6 7 8 9 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.
  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 Keenan, Philip C; McNeil, Raymond C (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373.
  4. ↑ Cousins, A. W. J. (1977). "Cape UBV magnitudes and colours of South circumpolar stars". South African Astronomical Observatory Circulars. 1: 51. Bibcode:1977SAAOC...1...51C.
  5. 1 2 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
  6. 1 2 3 4 5 6 Jofré, E; Petrucci, R; Saffe, C; Saker, L; de la Villarmois, E. Artur; Chavero, C; Gómez, M; Mauas, P. J. D (2015). "Stellar parameters and chemical abundances of 223 evolved stars with and without planets". Astronomy & Astrophysics. 574: A50. arXiv: 1410.6422 . Bibcode:2015A&A...574A..50J. doi:10.1051/0004-6361/201424474. S2CID   53666931.
  7. 1 2 da Silva, L.; et al. (November 2006). "Basic physical parameters of a selected sample of evolved stars". Astronomy and Astrophysics. 458 (2): 609–623. arXiv: astro-ph/0608160 . Bibcode:2006A&A...458..609D. doi:10.1051/0004-6361:20065105. S2CID   9341088.
  8. ↑ 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.
  9. ↑ 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.
  10. ↑ Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars". Monthly Notices of the Royal Astronomical Society. 472 (4): 3805–3820. arXiv: 1709.01160 . Bibcode:2017MNRAS.472.3805G. doi: 10.1093/mnras/stx2219 . eISSN   1365-2966. ISSN   0035-8711. S2CID   118879856.
  11. ↑ Cannon, Annie J. (1907). "Second catalogue of variable stars". Annals of Harvard College Observatory. 55: 1–94. Bibcode:1907AnHar..55....1C. S2CID   116966328.
  12. ↑ Gaposchkin, Cecilia Helena Payne; Gaposchkin, Sergei; Menzel, Donald Howard (1952). "Variable stars in Milton field 54". Annals of Harvard College Observatory. 115: 1–10. Bibcode:1952AnHar.115....1P.
  13. ↑ Keenan, P. C.; Pitts, R. E. (April 1980). "Revised MK spectral types for G, K ANS M stars". The Astrophysical Journal Supplement Series. 42: 541–563. Bibcode:1980ApJS...42..541K. doi: 10.1086/190662 . ISSN   0067-0049.
  14. ↑ Perryman, M. A. C.; Lindegren, L.; Kovalevsky, J.; Hoeg, E.; Bastian, U.; Bernacca, P. L.; Crézé, M.; Donati, F.; Grenon, M.; Grewing, M.; van Leeuwen, F. (July 1997). "The HIPPARCOS Catalogue". Astronomy and Astrophysics. 323: L49 –L52. Bibcode:1997A&A...323L..49P. ISSN   0004-6361.
  15. ↑ 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.


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.