OJ 287

Coordinates: Sky map 08h 54m 48.9s, +20° 06′ 31″
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OJ 287
Comparisons of large and small black holes in galaxy OJ 287 to the Solar System
Observation data (Epoch J2000)
Right ascension08h 54m 48.9s[1]
Declination+20° 06′ 31″[1]
Redshift0.306000 [1]
Distance3.5 Gly (1.073 Gpc)
TypeBL Lac[1]
Apparent magnitude (V)15.43[2]
Other designations
EGO 0851+202,[1] 3EG J0853+1941,[1] RGB J0854+201[1]
See also: Quasar, List of quasars

OJ 287 is a BL Lac object 5 billion light-years from Earth that has produced quasi-periodic optical outbursts going back approximately 120 years, as first apparent on photographic plates from 1891. Seen on photographic plates since at least 1887,[3] it was first detected at radio wavelengths during the course of the Ohio Sky Survey. It is a supermassive black hole binary (SMBHB).[4] The intrinsic brightness of the flashes corresponds to over a trillion times the Sun's luminosity, greater than the entire Milky Way galaxy's light output.[5]


Given the variability in the SMBHB's bursts and properties, multiple models have been proposed to account for these flashes. The first model proposed gives the mass of the primary black hole to be approximately 18.35 billion solar masses and the secondary black hole around 150 million. Other more recent models have proposed that the central supermassive black hole was calculated to have a mass of 100 million solar masses,[6] much less than previous estimations. This would make its Schwarzschild radius about 1.97 AU, which would swallow up part of the asteroid belt between Mars and Jupiter if it replaced the sun.

Black Hole Disk Flares In Galaxy OJ 287 (1:22; animation; 28 April 2020)
Interferometric observations of OJ287 by the VLBA resolved with the CHIRP algorithm and another algorithm by a group from Boston university.[7] OJ287 is a target candidate of the Event Horizon Telescope, 3C279 was targeted by it in 2017.

The optical light curve shows that OJ 287 has a periodic variation of 11–12 years with a narrow double peak at maximum brightness.[8] This kind of variation suggests that it is a binary supermassive black hole.[9] The double-burst variability is thought to result from the smaller black hole punching through the accretion disc of the larger black hole twice in every 12 years.[5]

A secondary orbits the larger one with an observed orbital period of ~12 years and a calculated eccentricity of ~0.65.[4] The maximum brightness is obtained when the minor component moves through the accretion disk of the supermassive component at perinigricon. The perinigricon and aponigricon of its orbit are ~3,250 and ~17,500 AU, the latter is also ~0.275 light-year and ~0.085 parsec. In recent models, the mass of the secondary supermassive black hole has been estimated to be approximately 125 million solar masses, although this has been debated through multiple studies. [CN]

An international research group, lead by Stefanie Komossa, calculated the mass of the primary black hole. "The results show that an exceptionally massive black hole exceeding 10 billion solar masses is no longer needed...the results favor models with a smaller mass of 100 million solar masses for the primary black hole".[6]

In order to reproduce all the known outbursts, the rotation of the primary black hole has to be 38% of the maximum allowed rotation for a Kerr black hole.[10][4]

The companion's orbit is decaying via the emission of gravitational radiation and it is expected to merge with the central black hole within approximately 10,000 years.[11][12][13]


  1. ^ a b c d e f g "NED results for object OJ +287". NASA/IPAC Extragalactic Database. Retrieved 2008-07-10.
  2. ^ "QSO J0854+2006". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 15 March 2018.
  3. ^ Camille M. Carlisle (13 January 2015). "Black Hole Binary En Route to Merger?". Sky & Telescope.
  4. ^ a b c Laine, S.; Dey, L.; Valtonen, M.; Gopakumar, A.; Zola, S.; Komossa, S.; Kidger, M.; Pihajoki, P.; Gómez, J.L.; Caton, D.; Ciprini, S.; Drozdz, M.; Gazeas, K.; Godunova, V.; Haque, S.; Hildebrandt, F.; Hudec, R.; Jermak, H.; Kong, A.K.H.; Lehto, H.; Liakos, A.; Matsumoto, K.; Mugrauer, M.; Pursimo, T.; Reichart, D.E.; Simon, A.; Siwak, M.; Sonbas, E. (2020). "Spitzer Observations of the Predicted Eddington Flare from Blazar OJ 287" (PDF). The Astrophysical Journal. 894 (1): L1. arXiv:2004.13392. Bibcode:2020ApJ...894L...1L. doi:10.3847/2041-8213/ab79a4. S2CID 216562421.
  5. ^ a b "Spitzer Telescope Reveals the Precise Timing of a Black Hole Dance". JPL.NASA.gov. Jet Propulsion Laboratory. 28 April 2020. Retrieved 2020-05-03.
  6. ^ a b "Weighing OJ 287 and the project MOMO". www.mpifr-bonn.mpg.de. Retrieved 2023-02-27.
  7. ^ Fish, Vincent; Akiyama, Kazunori; Bouman, Katherine; Chael, Andrew; Johnson, Michael; Doeleman, Sheperd; Blackburn, Lindy; Wardle, John; Freeman, William; the Event Horizon Telescope Collaboration (2016-10-27). "Observing—and Imaging—Active Galactic Nuclei with the Event Horizon Telescope". Galaxies. 4 (4): 54. arXiv:1607.03034. Bibcode:2016Galax...4...54F. doi:10.3390/galaxies4040054. ISSN 2075-4434.
  8. ^ Shi, Weizhao; Liu, Xiang; Song, Huagang (2007). "A new model for the periodic outbursts of the BL Lac object OJ287". Astrophysics and Space Science. 310 (1–2): 59–63. Bibcode:2007Ap&SS.310...59S. doi:10.1007/s10509-007-9413-z. S2CID 121149840.
  9. ^ Valtonen, M. J.; Nilsson, K.; Sillanpää, A.; et al. (2006). "The 2005 November Outburst in OJ 287 and the Binary Black Hole Model". The Astrophysical Journal. 643 (1): L9–L12. Bibcode:2006ApJ...643L...9V. doi:10.1086/505039.
  10. ^ Valtonen, M. J.; Mikkola, S.; Merritt, D.; et al. (February 2010). "Measuring the Spin of the Primary Black Hole in OJ287". The Astrophysical Journal. 709 (1): 725–732. arXiv:0912.1209. Bibcode:2010ApJ...709..725V. doi:10.1088/0004-637X/709/2/725. S2CID 119276181.
  11. ^ Shiga, David (10 January 2008). "Biggest black hole in the cosmos discovered". NewScientist.com news service.
  12. ^ Valtonen, M. J.; Lehto, H. J.; Sillanpaa, A.; et al. (2006). "Predicting the Next Outbursts of OJ 287 in 2006–2010". The Astrophysical Journal. 646 (1): 36–48. Bibcode:2006ApJ...646...36V. doi:10.1086/504884..
  13. ^ Dey, L.; Gopakumar, A.; Valtonen, M.; Zola, S.; Susobhanan, A.; Hudec, R.; Pihajoki, P.; Pursimo, T.; Berdyugin, A.; Piirola, V.; Ciprini, S.; Nilsson, K.; Jermak, H.; Kidger, M.; Komossa, S. (2019). "The Unique Blazar OJ 287 and Its Massive Binary Black Hole Central Engine". Universe. 5 (5): 108. arXiv:1905.02689. Bibcode:2019Univ....5..108D. doi:10.3390/universe5050108. S2CID 146808185.

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