HD 179821

HD 179821

HD 179821
Credit: Hubble Legacy Archive
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila
Right ascension 19h 13m 58.61s[1]
Declination +00° 07′ 31.9″[1]
Apparent magnitude (V) 8.19[2] (7.83 - 8.23[3])
Characteristics
Evolutionary stage YHG or post-AGB
Spectral type G4 0-Ia[4] (G5Ia - K4I[3])
Apparent magnitude (U) 10.81[5]
Apparent magnitude (B) 9.694[2]
Apparent magnitude (R) 8.2[6]
Apparent magnitude (J) 5.371[6]
Apparent magnitude (H) 4.998[6]
Apparent magnitude (K) 4.728[6]
B−V color index +1.504[2]
Variable type SRd[3]
Astrometry
Radial velocity (Rv)+81.8±3.7[7] km/s
Proper motion (μ) RA: −0.090[1] mas/yr
Dec.: −3.494[1] mas/yr
Parallax (π)0.1893 ± 0.0206 mas[1]
Distanceapprox. 17,000 ly
(approx. 5,300 pc)
Absolute magnitude (MV)−8.9[8][9] or −5.7[7]
Details
if a hypergiant
Mass19 - 30[7][10] M☉
Radius400 - 450[11] R☉
Luminosity126,000[11] - 295,000[9] L☉
Surface gravity (log g)0.5[8] cgs
Temperature4,898 - 6,761[11] K
Metallicity [Fe/H]0.0[8] dex
if post-AGB
Mass0.8[7] M☉
Radius147[7][a] R☉
Luminosity20,000+12,000
−7,400[7] L☉
Surface gravity (log g)0.5[8] cgs
Temperature5,660[7] K
Metallicity [Fe/H]0.0[8] dex
Other designations
HD 179821, V1427 Aql, AFGL 2343, BD−00°3679, HIP 94496, SAO 124414, IRAS 19114+0002, 2MASS J19135861+0007319
Database references
SIMBADdata

HD 179821 or V1427 Aquilae is either a post-red supergiant yellow hypergiant or a post-AGB yellow supergiant star in the constellation of Aquila, surrounded by a detached dust shell. It is a semi-regular variable nearing the end of its life.

  1. ^ a b c d e Cite error: The named reference dr3 was invoked but never defined (see the help page).
  2. ^ a b c Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27. Bibcode:2000A&A...355L..27H. doi:10.1888/0333750888/2862. ISBN 0333750888.
  3. ^ a b c Cite error: The named reference gcvs was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference perkins1989 was invoked but never defined (see the help page).
  5. ^ Nordhaus, J.; Minchev, I.; Sargent, B.; Forrest, W.; Blackman, E. G.; De Marco, O.; Kastner, J.; Balick, B.; Frank, A. (2008). "Towards a spectral technique for determining material geometry around evolved stars: Application to HD 179821". Monthly Notices of the Royal Astronomical Society. 388 (2): 716. arXiv:0801.2978. Bibcode:2008MNRAS.388..716N. doi:10.1111/j.1365-2966.2008.13428.x. S2CID 17468700.
  6. ^ a b c d Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C.
  7. ^ a b c d e f g Parthasarathy, M.; Jasniewicz, G.; Thěvenin, F. (2019). "Correction to: The puzzling high velocity G5 supergiant star HD 179821: New insight from Gaia DR2 data". Astrophysics and Space Science. 364 (2): 25. arXiv:1901.08995. Bibcode:2019Ap&SS.364...25P. doi:10.1007/s10509-019-3512-5. S2CID 119427229.
  8. ^ a b c d e Reddy, B. E.; Hrivnak, Bruce J. (April 1999). "Spectroscopic Study of HD 179821 (IRAS 19114+0002): Proto–Planetary Nebula or Supergiant?". The Astronomical Journal. 117 (4): 1834–1844. Bibcode:1999AJ....117.1834R. doi:10.1086/300815.
  9. ^ a b Klochkova, V. G. (2019). "Unity and Diversity of Yellow Hypergiants Family". Astrophysical Bulletin. 74 (4): 475–489. arXiv:1911.09387. Bibcode:2019AstBu..74..475K. doi:10.1134/S1990341319040138. S2CID 208202411.
  10. ^ Cite error: The named reference Ferguson2010 was invoked but never defined (see the help page).
  11. ^ a b c Cite error: The named reference van was invoked but never defined (see the help page).


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