HD 175640

HD 175640
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila
Right ascension 18h 56m 22.660s[1]
Declination −01° 47′ 59.50″[1]
Apparent magnitude (V) 6.20[2]
Characteristics
Spectral type B9 IIIp(HgMnEu st, CaMg wk)[3]
B9 V[4]
B−V color index −0.046±0.005[2]
Variable type Stable[4]
Astrometry
Radial velocity (Rv)−26±4[2] km/s
Proper motion (μ) RA: −2.811 mas/yr
Dec.: −19.318 mas/yr
Parallax (π)6.3201 ± 0.0448 mas[1]
Distance516 ± 4 ly
(158 ± 1 pc)
Absolute magnitude (MV)0.22[2]
Details
Mass3.12±0.1[4] M☉
Radius2.66±0.28[4] R☉
Luminosity94.56[2] L☉
Surface gravity (log g)4.03[5] cgs
Temperature12324±9[5] K
Metallicity [Fe/H]0.18±0.04[2] dex
Rotational velocity (v sin i)1.6±0.3[6] km/s
Other designations
BD−01°3602, FK5 3510, GC 25995, HD 175640, HIP 92963, HR 7143, SAO 142825[7]
Database references
SIMBADdata

HD 175640 is a star in the equatorial constellation of Aquila. It has an apparent visual magnitude of 6.20,[2] which is bright enough to be visible to the naked eye under suitable seeing conditions. The star is located at a distance of approximately 516 light years as determined through parallax measurements.[1] At that distance, the star's color is modified by an extinction of 0.36 magnitude due to interstellar dust.[8] It is drifting closer with a heliocentric radial velocity of roughly −26 km/s.[2]

This is classified as a mercury-manganese star, which is a late B-type chemically peculiar star of type CP3. A distinctive feature of this class of stars is an apparent extreme overabundance of the elements mercury and manganese.[9] It has a low longitudinal magnetic field strength of −0.6±2.2 G.[6] This is a particularly stable star, showing no signs of pulsation.[4] As with other HgMn stars, it is spinning slowly, showing a projected rotational velocity of 1.6 km/s.[6]

In 2007, some evidence was found that this may be a single-lined spectroscopic binary star system. In particular, shifts in radial velocity were observed in the range of 7 to −7 km/s.[10]

  1. ^ a b c d Cite error: The named reference GaiaEDR3 was invoked but never defined (see the help page).
  2. ^ a b c d e f g h Cite error: The named reference Anderson_Francis_2012 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Abt_Morrell_1995 was invoked but never defined (see the help page).
  4. ^ a b c d e Cite error: The named reference Ghazaryan_et_al_2013 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference García_Pérez_et_al_2021 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Kochukhov_et_al_2013 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Gontcharov_2012 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Castelli_Hubrig_2004 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Thiam_et_al_2007 was invoked but never defined (see the help page).