HD 157661

HD 157661
Observation data
Epoch J2000      Equinox J2000
Constellation Ara
Right ascension 17h 26m 51.97802s[1]
Declination –45° 50′ 34.9096″[1]
Apparent magnitude (V) 5.29[2] (5.70/6.46/7.6)[3]
Characteristics
Spectral type B7V + B9.5V + A0V[3]
U−B color index –0.34[2]
B−V color index –0.07[2]
R−I color index –0.03
Astrometry
Radial velocity (Rv)+8[4] km/s
Proper motion (μ) RA: –6.46[1] mas/yr
Dec.: –27.91[1] mas/yr
Parallax (π)5.13 ± 0.72 mas[1]
Distanceapprox. 640 ly
(approx. 190 pc)
Other designations
CD–45 11531, HD 157661, HIP 85389, HR 6477.[5]
Database references
SIMBADdata

HD 157661 is the Henry Draper Catalogue designation for a likely triple star[3] in the southern constellation of Ara. With a measured annual parallax of 5.13 mas,[1] is located at a distance of approximately 640 light-years (200 parsecs) from Earth. The combined apparent visual magnitude of the stars is 5.29,[2] which means it is faintly visible to the naked eye.

The inner components of this system consist of a pair of B-type main sequence stars. The brighter star has a magnitude of 5.70 and a stellar classification of B7 V. At an angular separation of 2.115 arcseconds is the magnitude 6.46 secondary component, which has a classification of B9.5 V. A third member of the system is a 7.6 magnitude A-type star at a separation of 103 arcseconds.[3]

  1. ^ a b c d e f Cite error: The named reference aaa474_2_653 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference aass34_1 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference mnras389_2_869 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference rgcrv was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).