4U 1700-37

4U 1700-37

A light curve for V884 Scorpii. The main plot, from TESS data,[1] shows the variation over several orbital periods. The inset plot, adapted from van Paradijs et al. (1984),[2] shows the average variation as a function of orbit phase.
Observation data
Epoch J2000      Equinox J2000
Constellation Scorpius
Right ascension 17h 03m 56.77256s[3]
Declination −37° 50′ 38.9133″[3]
Apparent magnitude (V) 6.51 (- 6.57) - 6.60[4]
Characteristics
Spectral type O6Iafcp[5]
U−B color index −0.727[6]
B−V color index +0.253[6]
Variable type Ellipsoidal + HMXB[4]
Astrometry
Radial velocity (Rv)−75.00±7.4[7] km/s
Proper motion (μ) RA: 2.414[3] mas/yr
Dec.: 5.022[3] mas/yr
Parallax (π)0.6327 ± 0.0259 mas[3]
Distance5,200 ± 200 ly
(1,580 ± 60 pc)
Absolute magnitude (MV)−6.52[8]
Orbit[9]
Period (P)3.4118 ± 0.0001 d
Eccentricity (e)0.17±0.06
Periastron epoch (T)JD 2443702.62±0.21
Argument of periastron (ω)
(primary)		54±24°
Semi-amplitude (K1)
(primary)		10.06 ± 0.66 km/s
Details[10]
O star
Mass58±11 M☉
Radius21.9+1.3
−0.5 R☉
Luminosity660,000 L☉
Temperature35,000±1,000 K
X-ray object
Mass2.44±0.27 M☉
Other designations
V884 Sco, CD−37°11206, HD 153919, HIP 83499, SAO 208356[11]
Database references
SIMBADdata

4U 1700-37 is one of the stronger binary X-ray sources in the sky, and is classified as a high-mass X-ray binary. It was discovered by the Uhuru satellite.[12] The "4U" designation refers to the fourth (and final) Uhuru catalog.

The X-ray source is associated with a bright (6.53 V magnitude) blue supergiant star HD 153919, which is orbited by an accreting compact object that must be either a neutron star or a black hole. The X-ray source is eclipsed by the star every 3.4 days, but no pulsations have yet been observed. The source is one of the ten brightest persistent X-ray sources in the 10-100 keV hard X-ray energy region.

Evidence of Compton cooling during an X-ray flare recorded by the Chandra X-ray telescope strongly suggests that the compact object is a neutron star;[13] if verified it would be among the most massive known, and near the boundary of the theoretical maximum.

4U 1700-37 is a runaway system. It has a high velocity of 63±5 km/s with respect to its parent cluster, NGC 6231. It was kicked out of the cluster about 2.2 million years ago by a supernova explosion.[14]

  1. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Paradijs was invoked but never defined (see the help page).
  3. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  4. ^ a b Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  5. ^ Sota, A.; Apellániz, J. Maíz; Morrell, N. I.; Barbá, R. H.; Walborn, N. R.; Gamen, R. C.; Arias, J. I.; Alfaro, E. J. (2014). "The Galactic O-Star Spectroscopic Survey (GOSSS). II. Bright Southern Stars". The Astrophysical Journal Supplement Series. 211 (1): 10. arXiv:1312.6222. Bibcode:2014ApJS..211...10S. doi:10.1088/0067-0049/211/1/10. S2CID 118847528.
  6. ^ a b Kozok, J. R. (1985). "Photometric observations of emission B-stars in the southern Milky Way". Astronomy and Astrophysics Supplement Series. 61: 387–405. Bibcode:1985A&AS...61..387K.
  7. ^ Kharchenko, N. V.; et al. (2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. S2CID 119323941.
  8. ^ Melnik, A. M.; Dambis, A. K. (2020), "Distance scale for high-luminosity stars in OB associations and in field with Gaia DR2. Spurious systematic motions", Astrophysics and Space Science, 365 (7): 112, arXiv:2006.14649, Bibcode:2020Ap&SS.365..112M, doi:10.1007/s10509-020-03827-0, S2CID 220128144.
  9. ^ Pourbaix, D.; et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727–732. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID 119387088.
  10. ^ Clark, J. S.; Goodwin, S. P.; Crowther, P. A.; Kaper, L.; Fairbairn, M.; Langer, N.; Brocksopp, C. (2002). "Physical parameters of the high-mass X-ray binary 4U1700-37". Astronomy & Astrophysics. 392 (3): 909–920. arXiv:astro-ph/0207334. Bibcode:2002A&A...392..909C. doi:10.1051/0004-6361:20021184. S2CID 119552560.
  11. ^ "HD 153919". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 4 September 2017.
  12. ^ Jones, C.; Forman, W.; Tananbaum, H.; Schreier, E.; Gursky, H.; Kellogg, E.; Giacconi, R. (1973). "Evidence for the Binary Nature of 2U 1700-37". The Astrophysical Journal. 181: L43. Bibcode:1973ApJ...181L..43J. doi:10.1086/181181.
  13. ^ Martinez-Chicharro, M.; Torrej ́on, J. M.; Oskinova, L.; F ̈urst, F.; Postnov, K.; Rodes-Roca, J. J.; Hainich, R.; Bodaghee, A. (2018). "Evidence of Compton cooling during an X-ray flare supports a neutron star nature of the compact object in 4U1700−37". Monthly Notices of the Royal Astronomical Society: Letters. 473 (1): L74–L78. arXiv:1710.01907. Bibcode:2018MNRAS.473L..74M. doi:10.1093/mnrasl/slx165. S2CID 56539478.
  14. ^ Van Der Meij, Vincent; Guo, Difeng; Kaper, Lex; Renzo, Mathieu (2021). "Confirming NGC 6231 as the parent cluster of the runaway high-mass X-ray binary HD 153919/4U 1700-37 with Gaia DR2". Astronomy & Astrophysics. 655: A31. arXiv:2108.12918. Bibcode:2021A&A...655A..31V. doi:10.1051/0004-6361/202040114. S2CID 237353522.