HD 155448

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HD 155448
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Scorpius
Right ascension 17h 12m 58.7680s[1]
Declination −32° 14′ 33.5690″[1]
Apparent magnitude (V) 8.72[2]
Characteristics
HD 155448 A
Evolutionary stage Main sequence
Spectral type B1 V
B−V color index −0.27±0.02
Characteristics
HD 155448Ba
Evolutionary stage main sequence star
Spectral type B6V
B−V color index −0.15±0.02[3]
HD 155448 Bb
Evolutionary stage main sequence star
Spectral type B9V[3]
B−V color index −0.08±0.02[3]
Characteristics
HD 155448 C
Evolutionary stage Main sequence
Spectral type B4 Ve[3]
B−V color index −0.19±0.02[3]
Characteristics
HD 155448 D
Evolutionary stage Main sequence
Spectral type B8 V[3]
B−V color index −0.11±0.02[3]
Astrometry
Proper motion (μ) RA: +2.77[1] mas/yr
Dec.: –0.85[1] mas/yr
Details[3]
A
Mass>7 M☉
Surface gravity (log g)4 cgs
Temperature25,000 K
Rotational velocity (v sin i)90±5 km/s
Details[3]
Ba
Mass5 M☉
Surface gravity (log g)4 cgs
Temperature14,000 K
Rotational velocity (v sin i)150±50 km/s
Bb
Mass3 M☉
Surface gravity (log g)4 cgs
Temperature10,000 K
Rotational velocity (v sin i)150±50 km/s
Details[3]
C
Mass6 M☉
Surface gravity (log g)4 cgs
Temperature16,000 K
Rotational velocity (v sin i)50±10 km/s
Details[3]
D
Mass3.5 M☉
Surface gravity (log g)4 cgs
Temperature12,000 K
Rotational velocity (v sin i)300±15 km/s
Other designations
CD–32°12461, HD 155448, HIP 84228, SAO 208540, WDS J17130-3215
Database references
SIMBADdata

HD 155448 is a quintuple star system consisting of 5 young B-type stars . With an apparent magnitude of 8.72,[2] it is too dim to be visible with the naked eye. Measurements from the Hipparcos spacecraft in 1997 give the system a distance of 1,976 light years with a high margin of error.[1] The New Hipparcos Reduction states a distance of 6,272 light years, giving a higher margin of error,[4] making both distances unreliable. Analysis in 2011 states that the stars aren't gravitationally bound to each other.[3]

Before 2011, this star was mistaken as either a Herbig Ae/Be star[5] or a post-AGB object.[6] When the system was studied in 2011, it was originally believed to contain only 4 stars (at least more than 2 stars) HD 155448 A, B, C, and D. However, a study conducted at the European Southern Observatory in Chile concluded that the "B" star is actually a binary star, thus reclassifying it as a quintuple star system.

All of the stars are currently on the ZAMS, which suggests a low luminosity and radius. At present HD 155448's components have masses ranging from 3-6 times the mass of the Sun, and temperatures ranging from 10,000-16,000 K. However, the A component has a mass greater than 7 solar masses and an effective temperature of 25,000 K.

References[]

  1. ^ a b c d Perryman, M. A. C.; Lindegren, L.; Kovalevsky, J.; Hoeg, E.; Bastian, U.; Bernacca, P. L.; Crézé, M.; Donati, F.; Grenon, M.; Grewing, M.; van Leeuwen, F. (1997-07-01). "The HIPPARCOS Catalogue". Astronomy and Astrophysics. 323: L49–L52. Bibcode:1997A&A...323L..49P. ISSN 0004-6361.
  2. ^ a b "HD 155448". sim-basic. Retrieved 21 March 2021.
  3. ^ a b c d e f g h i j k l Schütz, O.; Meeus, G.; Carmona, A.; Juhász, A.; Sterzik, M. F. (2011-09-01). "The young B-star quintuple system HD 155448". Astronomy and Astrophysics. 533: A54. arXiv:1108.1557. Bibcode:2011A&A...533A..54S. doi:10.1051/0004-6361/201016396. ISSN 0004-6361.
  4. ^ van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy & Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. ISSN 1432-0746.
  5. ^ Vioque, M.; Oudmaijer, R. D.; Baines, D.; Mendigutía, I.; Pérez-Martínez, R. (December 2018). "Gaia DR2 study of Herbig Ae/Be stars". Astronomy & Astrophysics. 620: A128. arXiv:1808.00476. Bibcode:2018A&A...620A.128V. doi:10.1051/0004-6361/201832870. ISSN 1432-0746.
  6. ^ Luna, R.; Cox, N. L. J.; Satorre, M. A.; García Hernández, D. A.; Suárez, O.; García Lario, P. (March 2008). "A search for diffuse bands in the circumstellar envelopes of post-AGB stars". Astronomy & Astrophysics. 480 (1): 133–148. arXiv:0711.1843. Bibcode:2008A&A...480..133L. doi:10.1051/0004-6361:20065282. ISSN 1432-0746.
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