NGC 300 X-1

NGC 300 X-1
	; Artistic representation of NGC 300 X-1
Observation data; Epoch J2000.0 Equinox J2000.0
Constellation	Sculptor
Right ascension	00h 55m 09.99s
Declination	−37° 42′ 12.2″
Characteristics
Evolutionary stage	Black hole + Wolf-Rayet
Spectral type	WNE
Astrometry
Distance	6,070,000±0.23 ly
Details
Black hole
Mass	17±4 M☉
WR
Mass	26+7; −5 M☉
Other designations
	NGC 300 X-1, 2XMM J005510.0-374212, CXOU J005510.0-374212
Database references
SIMBAD	data

NGC 300 X-1 is a high mass X-ray binary system located in the spiral galaxy NGC 300, approximately 6 million light-years away in the constellation of Sculptor.^[4]^[5] It consists of a stellar-mass black hole orbiting a Wolf–Rayet star (specifically of WN spectral type), making it one of only a few confirmed extragalactic Wolf–Rayet-black hole binary systems, the other prominent example being IC 10 X-1.^[3]^[6]

Observation

The system was first identified as an X-ray source, with periodic variability suggesting an orbital period.^[7] Subsequent spectroscopic observations using the Very Large Telescope (VLT) with the FORS2 instrument confirmed the association by detecting radial velocity variations in the He II λ4686 emission line of the Wolf–Rayet star (designated #41 in NGC 300), yielding an orbital period of 32.3±0.2 h, consistent with the X-ray period.^[5]

The black hole has a mass of 17±4 M_☉ and the WR star has a mass of 26+7
−5 M_☉. Both objects orbit each other at a distance of about 18.2 R_☉.^[3]

References

^ ^a ^b ^c "CXOU J005510.0-374212". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2026-03-10.
^ Rizzi, Luca; Bresolin, Fabio; Kudritzki, Rolf-Peter; Gieren, Wolfgang; Pietrzyński, Grzegorz (2006-02-20). "The Araucaria Project: The Distance to NGC 300 from the Red Giant Branch Tip Using HST ACS Imaging". The Astrophysical Journal. 638 (2): 766–771. arXiv:astro-ph/0510298. doi:10.1086/498705. ISSN 0004-637X.
^ ^a ^b ^c Binder, Breanna A.; Sy, Janelle M.; Eracleous, Michael; Christodoulou, Dimitris M.; Bhattacharya, Sayantan; Cappallo, Rigel; Laycock, Silas; Plucinsky, Paul P.; Williams, Benjamin F. (2021-03-01). "The Wolf–Rayet + Black Hole Binary NGC 300 X-1: What is the Mass of the Black Hole?". The Astrophysical Journal. 910 (1): 74. arXiv:2102.07065. doi:10.3847/1538-4357/abe6a9. ISSN 0004-637X.
^ Crowther, P. A.; Barnard, R.; Carpano, S.; Clark, J. S.; Dhillon, V. S.; Pollock, A. M. T. (2010-03-01). "NGC 300 X-1 is a Wolf-Rayet/black hole binary". Monthly Notices of the Royal Astronomical Society: Letters. 403 (1): L41–L45. arXiv:1001.4616. doi:10.1111/j.1745-3933.2010.00811.x. ISSN 1745-3933.
^ ^a ^b information@eso.org. "The black hole inside NGC 300 X-1 (artist's impression)". www.eso.org. Retrieved 2026-03-10.
^ "NGC 300 X-1 Fact Sheet - StarDate's Black Hole Encyclopedia". blackholes.stardate.org. Retrieved 2026-03-10.
^ Carpano, S.; Pollock, A. M. T.; Prestwich, A.; Crowther, P.; Wilms, J.; Yungelson, L.; Ehle, M. (2007-05-01). "A 33 hour period for the Wolf-Rayet/black hole X-ray binary candidate NGC 300 X-1". Astronomy & Astrophysics. 466 (2): L17–L20. arXiv:astro-ph/0703270. doi:10.1051/0004-6361:20077363. ISSN 0004-6361.

[:SIMBAD-1] "CXOU J005510.0-374212". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2026-03-10.

[2] Rizzi, Luca; Bresolin, Fabio; Kudritzki, Rolf-Peter; Gieren, Wolfgang; Pietrzyński, Grzegorz (2006-02-20). "The Araucaria Project: The Distance to NGC 300 from the Red Giant Branch Tip Using HST ACS Imaging". The Astrophysical Journal. 638 (2): 766–771. arXiv:astro-ph/0510298. doi:10.1086/498705. ISSN 0004-637X.

[:0-3] Binder, Breanna A.; Sy, Janelle M.; Eracleous, Michael; Christodoulou, Dimitris M.; Bhattacharya, Sayantan; Cappallo, Rigel; Laycock, Silas; Plucinsky, Paul P.; Williams, Benjamin F. (2021-03-01). "The Wolf–Rayet + Black Hole Binary NGC 300 X-1: What is the Mass of the Black Hole?". The Astrophysical Journal. 910 (1): 74. arXiv:2102.07065. doi:10.3847/1538-4357/abe6a9. ISSN 0004-637X.

[4] Crowther, P. A.; Barnard, R.; Carpano, S.; Clark, J. S.; Dhillon, V. S.; Pollock, A. M. T. (2010-03-01). "NGC 300 X-1 is a Wolf-Rayet/black hole binary". Monthly Notices of the Royal Astronomical Society: Letters. 403 (1): L41–L45. arXiv:1001.4616. doi:10.1111/j.1745-3933.2010.00811.x. ISSN 1745-3933.

[:1-5] rmation@eso.org. "The black hole inside NGC 300 X-1 (artist's impression)". www.eso.org. Retrieved 2026-03-10.

[6] "NGC 300 X-1 Fact Sheet - StarDate's Black Hole Encyclopedia". blackholes.stardate.org. Retrieved 2026-03-10.

[7] Carpano, S.; Pollock, A. M. T.; Prestwich, A.; Crowther, P.; Wilms, J.; Yungelson, L.; Ehle, M. (2007-05-01). "A 33 hour period for the Wolf-Rayet/black hole X-ray binary candidate NGC 300 X-1". Astronomy & Astrophysics. 466 (2): L17–L20. arXiv:astro-ph/0703270. doi:10.1051/0004-6361:20077363. ISSN 0004-6361.

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