M82 X-2
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 09h 55m 51.0s |
| Declination | 69° 40′ 45″ |
| Astrometry | |
| Distance | 12 million ly (3.5 million pc) |
| Other designations | |
| Database references | |
| SIMBAD | data |
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M82 X-2 is an X-ray pulsar located in the galaxy Messier 82, approximately 12 million light-years from Earth.[2] It is exceptionally luminous, radiating energy equivalent to approximately ten million Suns. This object is part of a binary system: If the pulsar is of an average size, 1.4 M☉, then its companion is at least 5.2 M☉.[3] On average, the pulsar rotates every 1.37 seconds, and revolves around its more massive companion every 2.5 days.[4]
M82 X-2 is an ultraluminous X-ray source (ULX), shining about 100 times brighter than theory suggests something of its mass should be able to. Its brightness is many times higher than the Eddington limit, a basic physics guideline that sets an upper limit on the brightness that an object of a given mass should be able to achieve. Possible explanations for violations of the Eddington limit include geometrical effects arising from the funneling of in-falling material along magnetic field lines.
While M82 X-2 was previously known as an X-ray source, it was not until an observation campaign to study the newly discovered supernova SN 2014J in January 2014 that X-2's true nature was uncovered.[5][6] Scientists looking at data from the NuSTAR spacecraft noticed a pulsing in the X-ray spectrum coming from near the supernova in Messier 82.[2][7] Data from the Chandra and Swift spacecraft was used to verify the NuSTAR findings and provide the necessary spatial resolution to determine the exact source.[3][4] After combining the NuSTAR and Chandra data, scientists were able to discern that M82 X-2 emitted both an X-ray beam and continuous broad X-ray radiation.[1] LXs). In 2023 new NuSTAR data confirmed that it exceeded the Eddington limit.[8][9]
See also
[edit]References
[edit]- ^ a b Smith et al. 1995, p. 204.
- ^ a b Stark, Anne M. (9 October 2014). "Dead star shines on". Lawrence Livermore National Laboratory. Archived from the original on 11 October 2014. Retrieved 11 October 2014.
- ^ a b Anderson, Janet; Watzke, Megan (8 October 2014). "Suspected Black Hole Unmasked as Ultraluminous Pulsar". NASA. Archived from the original on 16 October 2014. Retrieved 19 October 2014.
- ^ a b Smith et al. 1995, p. 202.
- ^ Fesenmaier, Kimm (8 October 2014). "NuSTAR Discovers Impossibly Bright Dead Star". Caltech. Archived from the original on 16 October 2014. Retrieved 19 October 2014.
- ^ Fesenmaier, Kimm (9 October 2014). "Pulsar as bright as 10 million suns baffles astronomers". Futurity. Archived from the original on 20 October 2014. Retrieved 19 October 2014.
- ^ Chou, Felicia; Clavin, Whitney (8 October 2014). "NASA's NuStar Telescope Discovers Shockingly Bright Dead Star". NASA. Archived from the original on 26 October 2014. Retrieved 26 October 2014.
- ^ Bachetti, Matteo; Heida, Marianne; Maccarone, Thomas; Huppenkothen, Daniela; Israel, Gian Luca; Barret, Didier; Brightman, Murray; Brumback, McKinley; Earnshaw, Hannah P.; Forster, Karl; Fürst, Felix; Grefenstette, Brian W.; Harrison, Fiona A.; Jaodand, Amruta D.; Madsen, Kristin K. (1 October 2022). "Orbital Decay in M82 X-2". The Astrophysical Journal. 937 (2): 125. arXiv:2112.00339. Bibcode:2022ApJ...937..125B. doi:10.3847/1538-4357/ac8d67. hdl:2299/25784. ISSN 0004-637X.
- ^ "NASA Study Helps Explain Limit-Breaking Ultra-Luminous X-Ray Sources". NASA Jet Propulsion Laboratory (JPL). Retrieved 18 April 2023.
Bibliography
[edit]- Bachetti, M.; Harrison, F. A.; Walton, D. J.; Grefenstette, B. W.; Chakrabarty, D.; et al. (9 October 2014). "An ultraluminous X-ray source powered by an accreting neutron star". Nature. 514 (7521): 202–204. arXiv:1410.3590. Bibcode:2014Natur.514..202B. doi:10.1038/nature13791. PMID 25297433. S2CID 4390221.
