Astronomy:Upsilon Aquarii

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Short description: Star in the constellation Aquarius
Upsilon Aquarii
Location of υ Aquarii (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aquarius
Right ascension  22h 34m 41.636s[1]
Declination −20° 42′ 29.58″[1]
Apparent magnitude (V) +5.21[2]
Characteristics
Spectral type F7 V[3]
B−V color index +0.44[2]
Astrometry
Radial velocity (Rv)−2.28±0.51[4] km/s
Proper motion (μ) RA: +221.185[1] mas/yr
Dec.: −147.090[1] mas/yr
Parallax (π)43.4396 ± 0.0828[1] mas
Distance75.1 ± 0.1 ly
(23.02 ± 0.04 pc)
Absolute magnitude (MV)+3.44[5]
Details
A
Mass1.32+0.08−0.04[6] M
Radius1.45±0.02[6] R
Luminosity3.61+0.16−0.14[6] L
Surface gravity (log g)4.27±0.09[6] cgs
Temperature6,606+52−46[6] K
Metallicity [Fe/H]0.08[7] dex
Rotational velocity (v sin i)34.9[8] km/s
Age0.25+0.75
−0.05
[7] to 1.69+0.62
−1.68
[6] Gyr
Other designations
υ Aquarii, υ Aqr, 59 Aquarii, BD−21 6251, FK5 849, GC 31516, HD 213845, HIP 111449, HR 8592, SAO 191235, PPM 273980[9]
Database references
SIMBADdata

Upsilon Aquarii is a binary star[10] system in the equatorial constellation of Aquarius. Its name is a Bayer designation that is Latinized from υ Aquarii, and abbreviated Upsilon Aqr or υ Aqr. This star is faintly visible to the naked eye with an apparent visual magnitude of 5.21.[2] Parallax measurements give a distance estimate of 75.1 light-years (23.0 parsecs) from Earth.[1] This is a high proper-motion star[11] that is drifting closer to the Sun with a radial velocity of –2.3 km/s.[4] It is part of the Hercules-Lyra association of co-moving stars.[10]

The primary component is an F-type main sequence star with a stellar classification of F7 V.[3] Age estimates range from 250[7] million to 1.7[6] billion years old, and it is spinning with a projected rotational velocity of 35 km/s.[8] The star has 1.32 times the mass of the Sun and 1.45 times the Sun's radius. It is radiating 3.6 times the Sun's luminosity from its photosphere at an effective temperature of 6,606 K,[6] giving it the yellow-white hue of an F-type star.[12]

The star displays an excess of near infrared radiation, suggesting it has a circumstellar disk of dusty debris.[13] This disk has a mean temperature of 75±17 K and is orbiting at an estimated radius of 84±41 astronomical unit|AU.[14] A faint stellar companion was detected in 2007 at the Gemini Observatory, with a separation of 6.09±0.03 from the primary.[10] This is equivalent to a physical projected separation of 139 astronomical unit|AU, which yields an estimated orbital period of ~1,330 years.[15] The debris disk is orbiting close to the dynamically unstable region of this system.[14]

As of 2024, the NASA Exoplanet Exploration Program has deemed this star one of the "most accessible to survey for potentially habitable exoplanets with the Habitable Worlds Observatory".[6]

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 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode1966CoLPL...4...99J. 
  3. 3.0 3.1 Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode1988mcts.book.....H. 
  4. 4.0 4.1 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  5. Nordström, B. et al. (May 2004), "The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ˜14 000 F and G dwarfs", Astronomy and Astrophysics 418: 989–1019, doi:10.1051/0004-6361:20035959, Bibcode2004A&A...418..989N. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 Harada, Caleb K. et al. (June 2024), "Setting the Stage for the Search for Life with the Habitable Worlds Observatory: Properties of 164 Promising Planet-survey Targets", The Astrophysical Journal Supplement Series 272 (2): id. 30, doi:10.3847/1538-4365/ad3e81, Bibcode2024ApJS..272...30H. 
  7. 7.0 7.1 7.2 Vigan, A. et al. (July 2017), "The VLT/NaCo large program to probe the occurrence of exoplanets and brown dwarfs at wide orbits. IV. Gravitational instability rarely forms wide, giant planets", Astronomy & Astrophysics 603: 19, doi:10.1051/0004-6361/201630133, A3, Bibcode2017A&A...603A...3V. 
  8. 8.0 8.1 Schröder, C. et al. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo", Astronomy and Astrophysics 493 (3): 1099–1107, doi:10.1051/0004-6361:200810377, Bibcode2009A&A...493.1099S. 
  9. "* ups Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+ups+Aqr. 
  10. 10.0 10.1 10.2 Lafrenière, David et al. (2007), "The Gemini Deep Planet Survey", The Astrophysical Journal 670 (2): 1367–1390, doi:10.1086/522826, Bibcode2007ApJ...670.1367L. 
  11. Luyten, W. J. (June 1995), "New Luyten Catalogue of stars with proper motions larger than two tenths of an arcsecond (NLTT)", VizieR Online Data Catalog, Bibcode1995yCat.1098....0L. 
  12. "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-07-02. 
  13. Ertel, S. et al. (October 2014), "A near-infrared interferometric survey of debris-disk stars. IV. An unbiased sample of 92 southern stars observed in H band with VLTI/PIONIER", Astronomy & Astrophysics 570: 20, doi:10.1051/0004-6361/201424438, A128, Bibcode2014A&A...570A.128E. 
  14. 14.0 14.1 Yelverton, Ben et al. (2019), "A statistically significant lack of debris discs in medium separation binary systems", Monthly Notices of the Royal Astronomical Society 488 (3): 3588–3606, doi:10.1093/mnras/stz1927, Bibcode2019MNRAS.488.3588Y. 
  15. Rodriguez, David R. et al. (May 2015), "Stellar multiplicity and debris discs: an unbiased sample", Monthly Notices of the Royal Astronomical Society 449 (3): 3160–3170, doi:10.1093/mnras/stv483, Bibcode2015MNRAS.449.3160R.