OJ 287
Encyclopedia
OJ 287 is a BL Lac object
located 3.5 billion
light years
away that has produced quasi-periodic optical outbursts going back approximately 120 years, as first apparent on photographic plates from 1891. It was first detected at radio wavelengths during the course of the Ohio Sky Survey
.
Its central supermassive black hole
is claimed to be the largest known, with a mass of 18 billion solar masses, more than six times the value calculated for the previous largest object.
The optical light curve shows that OJ 287 has a periodic variation of 11–12 years with a narrow double peak at maximum brightness. This kind of variation suggests that an engine is a binary supermassive black hole
where a smaller black hole with a mass of only 100 million MSun orbits the larger one with an observed 11-12 year orbital period. The maximum brightness is obtained when the minor component moves through the accretion disk of the supermassive component at perinigricon.
The mass was calculated by a team led by Mauri Valtonen
of Tuorla Observatory
in Finland, and the group's results were presented to the public at the 211th meeting of the American Astronomical Society
(AAS). The timing of these outbursts allows the precession
of the companion's elliptical orbit to be measured (39° per orbit), which allows the mass of the central black hole to be calculated using Albert Einstein
's principles of General relativity
(see Kepler problem in general relativity
).
The accuracy of this measurement has been called into question due to the limited number and precision of observed companion orbits, but the calculated value will be further refined using future measurements. 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. The study has been published in the Astrophysical Journal
.
In order to reproduce all the known outbursts, a recent study shows that the rotation of the primary black hole has to be 28% of the maximum allowed rotation for a Kerr black hole.
BL Lac object
A BL Lacertae object or BL Lac object is a type of active galaxy with an active galactic nucleus and is named after its prototype, BL Lacertae. In contrast to other types of active galactic nuclei, BL Lacs are characterized by rapid and large-amplitude flux variability and significant optical...
located 3.5 billion
1000000000 (number)
1,000,000,000 is the natural number following 999,999,999 and preceding 1,000,000,001.In scientific notation, it is written as 109....
light years
Light Years
Light Years is the seventh studio album by Australian recording artist Kylie Minogue. It was released on 25 September 2000 by Parlophone and Mushroom Records. The album's style was indicative of her return to "mainstream pop dance tunes"....
away that has produced quasi-periodic optical outbursts going back approximately 120 years, as first apparent on photographic plates from 1891. It was first detected at radio wavelengths during the course of the Ohio Sky Survey
Ohio Sky Survey
The Ohio Sky Survey was an astronomical survey of extragalactic radio sources. Data were taken between 1965 and 1971 using the Big Ear radio telescope at the Ohio State University Radio Observatory , also known as the "Big Ear Radio Observatory "....
.
Its central supermassive black hole
Supermassive black hole
A supermassive black hole is the largest type of black hole in a galaxy, in the order of hundreds of thousands to billions of solar masses. Most, and possibly all galaxies, including the Milky Way, are believed to contain supermassive black holes at their centers.Supermassive black holes have...
is claimed to be the largest known, with a mass of 18 billion solar masses, more than six times the value calculated for the previous largest object.
The optical light curve shows that OJ 287 has a periodic variation of 11–12 years with a narrow double peak at maximum brightness. This kind of variation suggests that an engine is a binary supermassive black hole
Supermassive black hole
A supermassive black hole is the largest type of black hole in a galaxy, in the order of hundreds of thousands to billions of solar masses. Most, and possibly all galaxies, including the Milky Way, are believed to contain supermassive black holes at their centers.Supermassive black holes have...
where a smaller black hole with a mass of only 100 million MSun orbits the larger one with an observed 11-12 year orbital period. The maximum brightness is obtained when the minor component moves through the accretion disk of the supermassive component at perinigricon.
The mass was calculated by a team led by Mauri Valtonen
Mauri Valtonen
Mauri Valtonen is a Finnish astronomer and professor at the University of Turku. His fields of scientific interest include active galaxies, cosmology, and the three-body problem.Valtonen completed a Ph.D. from Cambridge University in 1975...
of Tuorla Observatory
Tuorla Observatory
Tuorla Observatory is the Department of Astronomy at the University of Turku, southwest Finland. Currently it is the largest astronomical research institute in Finland...
in Finland, and the group's results were presented to the public at the 211th meeting of the American Astronomical Society
American Astronomical Society
The American Astronomical Society is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC...
(AAS). The timing of these outbursts allows the precession
Precession
Precession is a change in the orientation of the rotation axis of a rotating body. It can be defined as a change in direction of the rotation axis in which the second Euler angle is constant...
of the companion's elliptical orbit to be measured (39° per orbit), which allows the mass of the central black hole to be calculated using Albert Einstein
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
's principles of General relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
(see Kepler problem in general relativity
Kepler problem in general relativity
The two-body problem in general relativity is to determine the motion and gravitational field of two bodies interacting with one another by gravitation, as described by the field equations of general relativity. Solving the Kepler problem is essential to calculate the bending of light by gravity...
).
The accuracy of this measurement has been called into question due to the limited number and precision of observed companion orbits, but the calculated value will be further refined using future measurements. 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. The study has been published in the Astrophysical Journal
Astrophysical Journal
The Astrophysical Journal is a peer-reviewed scientific journal covering astronomy and astrophysics. It was founded in 1895 by the American astronomers George Ellery Hale and James Edward Keeler. It publishes three 500-page issues per month....
.
In order to reproduce all the known outbursts, a recent study shows that the rotation of the primary black hole has to be 28% of the maximum allowed rotation for a Kerr black hole.
External links
- 18 Billions of Suns Support Einstein (Calar Alto ObservatoryCalar Alto ObservatoryThe Calar Alto Observatory is an astronomical observatory owned and operated jointly by the Max-Planck-Institut für Astronomie in Heidelberg, Germany, and the Instituto...
) - Historical lightcurve of OJ 287
- Object: OJ 287 (SAO Observers)
- OJ 287 2005-2008 Project (Tuorla Observatory)
- A Supermassive Black Hole Pairing (Centauri Dreams)
- OJ 287 2005-2008 Project
