Astronomy:Rho Coronae Borealis

From HandWiki
Short description: Star in the constellation Corona Borealis
Not to be confused with R Coronae Borealis.
ρ Coronae Borealis
Location of ρ Coronae Borealis (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Corona Borealis
Right ascension  16h 01m 02.66049s[1]
Declination +33° 18′ 12.6395″[1]
Apparent magnitude (V) 5.39[2]
Characteristics
Evolutionary stage subgiant[2][1]
Spectral type G0V[3]
B−V color index 0.61[2]
Astrometry
Radial velocity (Rv)−8.655±0.109[4] km/s
Proper motion (μ) RA: −198.278(43)[1] mas/yr
Dec.: −772.245(53)[1] mas/yr
Parallax (π)57.1076 ± 0.0508[1] mas
Distance57.11 ± 0.05 ly
(17.51 ± 0.02 pc)
Absolute magnitude (MV)+4.21[5]
Details
Mass0.95±0.01[2] M☉
Radius1.304±0.012[6] R☉
Luminosity1.749±0.040[6] L☉
Surface gravity (log g)4.25±0.05[2] cgs
Temperature5,817±24[2] K
Metallicity [Fe/H]−0.24±0.08[5] dex
Rotation20.3±1.8 d[6]
Rotational velocity (v sin i)0.8±0.3[2] km/s
Age10.2±0.5[2] Gyr
Other designations
ρ CrB, 15 CrB, BD+33°2663, GC 21527, GJ 606.2, HD 143761, HIP 78459, HR 5968, SAO 65024, CCDM J16011+3318A, WDS J16010+3318A, LHS 3145, LTT 14764, 2MASS J16010264+3318124[7]
Database references
SIMBADdata
Exoplanet ArchiveCrB data
ARICNSdata

Rho Coronae Borealis is a yellow-hued star in the northern constellation of Corona Borealis. Its name is a Bayer designation that is Latinized from ρ Coronae Borealis and abbreviated Rho CrB or ρ CrB. It is faintly visible to the naked eye with an apparent visual magnitude of 5.39.[2] Based on parallax measurements, it is located at a distance of 57.1 light-years (17.5 parsecs). The star is thought to be a slightly more evolved star that is otherwise similar to the Sun with nearly the same mass, radius, and luminosity. It is orbited by three known exoplanets.

Stellar properties

Rho Coronae Borealis is a yellow subgiant star of the spectral type G0V. The star is estimated to have 96 percent of the Sun's mass,[2] along with 1.3 times its radius,[6] and 1.7 times its luminosity.[6] It may only be 51 to 65 percent as enriched with elements heavier than hydrogen (based on its abundance of iron)[5] and is likely somewhat older than the Sun at around ten billion years old.[2]

The Rho Coronae Borealis has a relatively fast rotation with a period approximately 20 days, even though at this age stars are hypothesized to decouple their rotational evolution and magnetic activity.[6]

Multiple star catalogs list a 10th-magnitude companion about two arc-minutes away,[8] but it is an unrelated background object.[9]

Planetary system

An extrasolar planet in a 39.8-day orbit around Rho Coronae Borealis was discovered in 1997 by observing the star's radial velocity variations.[10] This detection method only gives a lower limit on the true mass of the companion. In 2001, preliminary Hipparcos astrometric satellite data indicated that the orbital inclination of the star's companion was 0.5°, nearly face-on, implying that its mass was as much as 115 times Jupiter's.[11] A paper published in 2011 supported this claim using a new reduction of the astrometric data, with an updated mass value of 169.7 times Jupiter, with a 3σ confidence region 100.1 to 199.6 Jupiter masses.[12] Such a massive body would be a dim red dwarf star, not a planet. However, interferometric observations published in 2016 found no evidence for a red dwarf at the expected separation.[13] A 2022 astrometric study analysing Hipparcos and Gaia proper motion measurements also found no evidence for a companion at a high signal-to-noise ratio.[14]

A second planetary companion was detected in a 102-day orbit.[13] The discovery of another two planets was reported in 2023.[2] However, a 2026 follow-up study by the same authors found that the apparent outermost planet d (with a 281-day period) was a spurious detection caused by instrumental errors from the EXPRES spectrograph. The system currently has three known planets: e, b & c.[4]

The evolution of the parent star, nearing the conclusion of its life cycle, has been regarded as a model for the potential evolution of our planetary system. This is especially relevant for predicting whether the Sun will eventually engulf the Earth at the end of its own lifecycle (cf. Future of Earth).[15]

The Rho Coronae Borealis planetary system[4]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
e ≥3.71±0.60 M⊕ 0.1061±0.0011[2] 12.904±0.011 0.082±0.047 — —
b ≥1.0950±0.0002 MJ 0.2245+0.0023
−0.0024[2] 		39.849±0.002 0.046±0.002 — —
c ≥27.4±0.7 M⊕ 0.4206+0.0044
−0.0045[2] 		102.0±0.2 0.048±0.034 — —

Circumstellar material

In October 1999, astronomers at the University of Arizona announced the existence of a circumstellar disk around the star.[16] Follow-up observations with the Spitzer Space Telescope failed to detect any infrared excess at 24- or 70-micrometre wavelengths, which would be expected if a disk were present.[17][18][19] No evidence for a disk was detected in observations with the Herschel Space Observatory either.[20]

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. ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 Brewer, John M. et al. (June 2023). "EXPRES IV: Two Additional Planets Orbiting ρ Coronae Borealis Reveal Uncommon System Architecture". The Astronomical Journal 166 (2): 46. doi:10.3847/1538-3881/acdd6f. Bibcode: 2023AJ....166...46B. 
  3. ↑ von Braun, Kaspar et al. (2014). "Stellar diameters and temperatures - V. 11 newly characterized exoplanet host stars". Monthly Notices of the Royal Astronomical Society 438 (3): 2413–2425. doi:10.1093/mnras/stt2360. Bibcode: 2014MNRAS.438.2413V. 
  4. ↑ 4.0 4.1 4.2 Zhao, Lily L. et al. (February 2026). "Uncovering Hidden Systematics in Extreme-Precision Radial Velocity Measurements". The Astrophysical Journal Supplement Series 282 (2): id. 71. doi:10.3847/1538-4365/ae3088. Bibcode: 2026ApJS..282...71Z. 
  5. ↑ 5.0 5.1 5.2 Fuhrmann, Klaus et al. (1998). "F- and G-type stars with planetary companions: Upsilon Andromedae, rho (1) Cancri, tau Bootis, 16 Cygni and rho Coronae Borealis". Astronomy and Astrophysics 336: 942. Bibcode: 1998A&A...336..942F. 
  6. ↑ 6.0 6.1 6.2 6.3 6.4 6.5 Metcalfe, Travis S. et al. (2021). "Magnetic and Rotational Evolution of ρ CrB from Asteroseismology with TESS". The Astrophysical Journal 921 (2): 122. doi:10.3847/1538-4357/ac1f19. Bibcode: 2021ApJ...921..122M. 
  7. ↑ "rho CrB". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=rho+CrB. 
  8. ↑ Mason, B. D. et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal 122 (6): 3466. doi:10.1086/323920. Bibcode: 2001AJ....122.3466M. 
  9. ↑ 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.
  10. ↑ Noyes, Robert W. et al. (1997). "A Planet Orbiting the Star ρ Coronae Borealis". Astrophysical Journal 483 (2): L111–L114. doi:10.1086/310754. Bibcode: 1997ApJ...483L.111N. 
  11. ↑ Han, Inwoo et al. (2001). "Preliminary Astrometric Masses for Proposed Extrasolar Planetary Companions". The Astrophysical Journal 548 (1): L57–L60. doi:10.1086/318927. Bibcode: 2001ApJ...548L..57H. 
  12. ↑ Reffert, S.; Quirrenbach, A. (2011). "Mass constraints on substellar companion candidates from the re-reduced Hipparcos intermediate astrometric data: nine confirmed planets and two confirmed brown dwarfs". Astronomy & Astrophysics 527: id.A140. doi:10.1051/0004-6361/201015861. Bibcode: 2011A&A...527A.140R. 
  13. ↑ 13.0 13.1 Fulton, Benjamin J. (October 2016). "Three Temperate Neptunes Orbiting Nearby Stars". The Astrophysical Journal 830 (1): 46. doi:10.3847/0004-637X/830/1/46. Bibcode: 2016ApJ...830...46F. 
  14. ↑ Kervella, Pierre et al. (January 2022). "Stellar and substellar companions from Gaia EDR3. Proper-motion anomaly and resolved common proper-motion pairs". Astronomy and Astrophysics 657: A7. doi:10.1051/0004-6361/202142146. ISSN 0004-6361. Bibcode: 2022A&A...657A...7K.  Rho CrB's database entry at VizieR.
  15. ↑ O'Callaghan, Jonathan (December 20, 2023). "New Clues for What Will Happen When the Sun Eats the Earth". https://www.quantamagazine.org/new-clues-for-what-will-happen-when-the-sun-eats-the-earth-20231220/. 
  16. ↑ Trilling, D. E. et al. (2000). "Circumstellar Dust Disks around Stars with Known Planetary Companions". The Astrophysical Journal 529 (1): 499–505. doi:10.1086/308280. Bibcode: 2000ApJ...529..499T. 
  17. ↑ Beichman, C. A. et al. (2005). "Planets and Infrared Excesses: Preliminary Results from a Spitzer MIPS Survey of Solar-Type Stars". The Astrophysical Journal 622 (2): 1160–1170. doi:10.1086/428115. Bibcode: 2005ApJ...622.1160B. 
  18. ↑ Bryden, G. et al. (2009). "Planets and Debris Disks: Results from a Spitzer/MIPS Search for Infrared Excess". The Astrophysical Journal 705 (2): 1226–1236. doi:10.1088/0004-637X/705/2/1226. Bibcode: 2009ApJ...705.1226B. 
  19. ↑ Caer McCabe; Carlotta Pham. "Catalog of withdrawn or refuted resolved Disks". Catalog of Resolved Circumstellar Disks. Archived from the original on 2009-01-05. https://web.archive.org/web/20090105162427/http://www.circumstellardisks.org/cgi-bin/refuted_frame.pl. Retrieved 2010-04-03. 
  20. ↑ Marshall, J. P. et al. (2014). "Correlations between the stellar, planetary, and debris components of exoplanet systems observed by Herschel". Astronomy & Astrophysics 565: id.A15. doi:10.1051/0004-6361/201323058. Bibcode: 2014A&A...565A..15M. 

Coordinates: Sky map 16h 01m 02.6616s, +33° 18′ 12.634″



Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:Rho_Coronae_Borealis&oldid=4559340"