Astronomy:95 Herculis

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Short description: Double star in the constellation Hercules
95 Herculis
Location of 95 Herculis in Hercules (circled)
Observation data
{{#ifeq:J2000|J2000.0 (ICRS)|Epoch J2000.0      Equinox J2000.0 (ICRS)| Epoch J2000      [[Astronomy:Equinox (celestial coordinates)|Equinox J2000}}
Constellation Hercules
A
Right ascension  18h 01m 30.40868s[1]
Declination +21° 35′ 44.8121″[1]
Apparent magnitude (V) 4.83±0.01[2]
B
Right ascension  18h 01m 29.96397s[3]
Declination +21° 35′ 43.4043″[3]
Apparent magnitude (V) 5.10[4]
Characteristics
A
Evolutionary stage Giant star[5] or subgiant[2]
Spectral type A2IV[2]
B
Evolutionary stage Horizontal branch[6]
Spectral type G5III[4]
Astrometry
A
Radial velocity (Rv)−44.86±3.07[1] km/s
Proper motion (μ) RA: +9.200[1] mas/yr
Dec.: +38.438[1] mas/yr
Parallax (π)7.5526 ± 0.0713[1] mas
Distance432 ± 4 ly
(132 ± 1 pc)
B
Radial velocity (Rv)−32.9±0.12[3] km/s
Proper motion (μ) RA: +8.995 mas/yr
Dec.: +36.267 mas/yr
Parallax (π)7.5492 ± 0.0592[3] mas
Distance432 ± 3 ly
(132 ± 1 pc)
Details
A
Mass3.1[7] M☉
Radius6.0[8] R☉
Luminosity156[7] L☉
Temperature8,211[8] K
Rotational velocity (v sin i)233[9] km/s
B
Mass3.2[5] M☉
Radius16.5[8] R☉
Luminosity172[3] L☉
Surface gravity (log g)2.77[10] cgs
Temperature5,037[10] K
Rotational velocity (v sin i)5.7[11] km/s
Age979[10] Myr
Other designations
Bodu, 95 Her, HIP 88267, ADS 10993, WDS J18015+2136
A: HD 164669, HR 6730, ADS 10993, TYC 1566-3674-1
B: HD 164668, HR 6729, TYC 1566-3675-1
Database references
SIMBADdata
A
B

95 Herculis, also named Bodu,[12] is a double stellar system in the constellation Hercules, located 432 light-years from Earth.

Nomenclature

95 Herculis is the star's Flamsteed designation. This star, together with 93 Herculis, 102 Herculis, and 109 Herculis, formed the now obsolete constellation of Cerberus.[13]

In Chinese astronomy, 95 Herculis and 102 Herculis form the asterism Bó Dù (帛度, "Textile Ruler").[14] The IAU Working Group on Star Names approved the name Bodu for this star on 17 June 2025 and it is now so entered in the IAU Catalog of Star Names.[12]

Characteristics

From the naked eye, 95 Herculis appears as a single star shining at apparent magnitude 4.31. However, when further scrutinized using a telescope, it is revealed to be a double star, with two components separated by 6.3 arcseconds. This system has a color contrast due to the difference of each star's effective temperature.[5]

The brightest component, called 95 Herculis A, is a white giant[6] or subgiant with an apparent magnitude of 4.8.[2] This evolved star has 3.1 times more mass than the Sun, is six times wider, and is 156 times more luminous. Its effective temperature of 8,211 K give it a blue-white hue typical of A-type stars. It is spinning rapidly with an projected rotational velocity of 233 km/s.

The secondary is called 95 Herculis B, a yellow giant[6] of apparent magnitude 5.1.[4] It is the most evolved star in the pair, having reached the helium burning stage, while 95 Herculis A is still in the transition from hydrogen burning to helium burning.[6] Albeit fainter than 95 Her A, 95 Her B emits a significant part of its luminosity in the infrared, and hence the bolometric luminosity is 172 times solar. It is 3.2 times more massive than the Sun and 16.5 times wider. The effective temperature of the star is 5,037 K.

Orbit

The orbital elements of 95 Herculis are not accurately known and no orbital motion has been detected. However, their projected separation is calculated at 900 astronomical units, with an orbital period of at least 11,000 years.[5]

See also

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  2. ↑ 2.0 2.1 2.2 2.3 "95 Her A". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=95+Her+A. 
  3. ↑ 3.0 3.1 3.2 3.3 3.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  4. ↑ 4.0 4.1 4.2 "95 Her B". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=95+Her+B. 
  5. ↑ 5.0 5.1 5.2 5.3 Kaler, Jim. "95 Herculis". http://stars.astro.illinois.edu/sow/95her.html. 
  6. ↑ 6.0 6.1 6.2 6.3 "95 Herculis" (in en). https://www.havastro.co.uk/95-herculis. 
  7. ↑ 7.0 7.1 Quintana, Alexis L.; Wright, Nicholas J.; Martínez García, Juan (2025). "A census of OB stars within 1 KPC and the star formation and core collapse supernova rates of the Milky Way". Monthly Notices of the Royal Astronomical Society 538 (3): 1367. doi:10.1093/mnras/staf083. Bibcode: 2025MNRAS.538.1367Q. 
  8. ↑ 8.0 8.1 8.2 Stassun, Keivan G. et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode: 2019AJ....158..138S. 
  9. ↑ Royer, F.; Grenier, S.; Baylac, M.-O.; Gómez, A. E.; Zorec, J. (2002). "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin I". Astronomy and Astrophysics 393: 897. doi:10.1051/0004-6361:20020943. Bibcode: 2002A&A...393..897R. 
  10. ↑ 10.0 10.1 10.2 Kordopatis, G.; Schultheis, M.; McMillan, P. J.; Palicio, P. A.; De Laverny, P.; Recio-Blanco, A.; Creevey, O.; Álvarez, M. A. et al. (2023). "Stellar ages, masses, extinctions, and orbital parameters based on spectroscopic parameters of Gaia DR3". Astronomy and Astrophysics 669: A104. doi:10.1051/0004-6361/202244283. Bibcode: 2023A&A...669A.104K. 
  11. ↑ De Medeiros, J. R.; do Nascimento, J. D., Jr.; Sankarankutty, S.; Costa, J. M.; Maia, M. R. G. (2000). "Rotation and lithium in single giant stars". Astronomy and Astrophysics 363: 239. Bibcode: 2000A&A...363..239D. 
  12. ↑ 12.0 12.1 "IAU Catalog of Star Names". https://exopla.net/star-names/modern-iau-star-names/. 
  13. ↑ Ridpath, Ian. "Star Tales - Cerberus". http://www.ianridpath.com/startales/cerberus.html. 
  14. ↑ "Bodu (帛度)". IAU Working Group on Star Names. https://xing.fmi.uni-jena.de/mediawiki/index.php/Bodu. 



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