B2 1308+326
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| B2 1308+326 | |
|---|---|
 The BL Lac object B2 1308+326. | |
| Observation data (J2000.0 epoch) | |
| Constellation | Canes Venatici |
| Right ascension | 13h 10m 28.6638s |
| Declination | +32° 20′ 43.783″ |
| Redshift | 0.997 |
| Heliocentric radial velocity | 503,199 km/s |
| Apparent magnitude (V) | 15.24 |
| Apparent magnitude (B) | 15.61 |
| Characteristics | |
| Type | Opt var; FSRQ, BL LAC |
| Other designations | |
| IRAS F13080+3237, OHIO P 313, US 371, QSO B1308+326, CSO 836, INTREF 546, NVSS J131028+322044, V* AU CVn, H-ATLAS J131028.7+322043, 5C 12.659, 7C 1308+3236, 2E 2979, B2 1308+32 | |
B2 1308+326 known as OP 313 or AU CVn, is a BL Lacertae object[1] located in the constellation of Canes Venatici. It has a redshift of (z) 0.997[2] and was initially discovered as a variable star in 1959 before being identified with its optical counterpart in 1972.[3] Its radio spectrum is flat, making it a FSRQ (flat-spectrum radio quasar).[4][5][6]
B2 1308+326 is found variable on the electromagnetic spectrum. It is classified a blazar[7] although some studies described it as a transitional or change-looking due to it experiencing a shift in synchrotron peak frequencies.[8][9] It is known to show an outburst in 1978 which it displayed extreme degrees of polarization, found rapidly variable in both position and degree angles on a time scale for 15 minutes.[10]
A gamma ray flare was detected in 2014.[11] In June 2022, B2 1308+326 showed an optical flare, subsequently reaching a historic maximum brightness with a slight decreased flux of 0.2-0.3 magnitude in R-band observed a month later.[12][13] Significant gamma ray activity was detected on 1 December 2023.[14]
Radio imaging of B2 1308+326 made by Very long baseline interferometry at 5 GHz showed it has an extended region and simple radio core structure measuring 1.3 x 0.6 in size with an orientation along the 30° position angle. When shown at 8.4 GHz, the source is then resolved into a bright core with a brightness temperature of 1012 Kelvin and a jet structure.[15] Subsequent observations found the core has a 3% polarization with a flat spectrum and contains perpendicular electric field vectors to the jet's direction which turns almost parallel upon 2 mas from the core.[16] Imaging by Very Large Array showed it has a dominant component and secondary component located 12 arcseconds north as well as a diffused halo surrounding the structure.[17]
A light curve of B2 1308+326 during 10 years of observations between 1976 and 1986 was obtained. Data from the light curve showed the total variability range of B2 1308+326 was 3.0 magnitude with the detection of multiple flares. According to observations in early 1987, it was found to be a faint state.[18] The light curve at 4.8–90 GHz frequencies also showed B2 1308+326 had two complex outbursts, one between 1980-1988 and the second between 1988 and 2001 accompanied by three flares.[19]
References
- ↑ Sitko, M. L.; Stein, W. A.; Schmidt, G. D. (1984-07-01). "Wavelength-dependent polarization in the optical flux of the BL Lacertae object B2 1308+326". The Astrophysical Journal. 282: 29–32. Bibcode:1984ApJ...282...29S. doi:10.1086/162173. ISSN 0004-637X.
- ↑ Watson, D.; Smith, N.; Hanlon, L.; McBreen, B.; Quilligan, F.; Tashiro, M.; Metcalfe, L.; Doyle, P.; Teraesranta, H. (2000-09-13), "ASCA and other contemporaneous observations of the blazar B2 1308+326", Astronomy and Astrophysics, 364: 43, arXiv:astro-ph/0009202, Bibcode:2000A&A...364...43W
- ↑ "Au CVn (B2 1308+326, OP+313)". Frankfurt Quasar Monitoring. Retrieved 2025-01-05.
- ↑ Bachev, R. (2022-06-01). "An update on B2 1308+326". The Astronomer's Telegram. 15447: 1. Bibcode:2022ATel15447....1B.
- ↑ Buson, Sara (April 2014). "Fermi LAT Detection of a GeV Flare from OP 313 (B2 1308+32)". The Astronomer's Telegram. 6068: 1. Bibcode:2014ATel.6068....1S.
- ↑ Vlasyuk, V. V.; Spiridonova, O. I.; Maslennikova, O. A. (2022-06-01). "The FSRQ B2 1308+326: reaching the new absolute maximum and still brightening". The Astronomer's Telegram. 15459: 1. Bibcode:2022ATel15459....1V.
- ↑ Corcoran, Riley M.; Slater, John J.; Neal, Warner S.; Balonek, Thomas J. (2022-04-01). "Continued Optical Flaring in Blazar 1308+326". The Astronomer's Telegram. 15334: 1. Bibcode:2022ATel15334....1C.
- ↑ Pandey, Ashwani; Kushwaha, Pankaj; Wiita, Paul J.; Prince, Raj; Czerny, Bożena; Stalin, C. S. (2024-01-01). "Origin of the broadband emission from the transition blazar B2 1308+326". Astronomy & Astrophysics. 681: A116. arXiv:2310.05096. Bibcode:2024A&A...681A.116P. doi:10.1051/0004-6361/202347719. ISSN 0004-6361.
- ↑ Pandey, Ashwani; Hu, Chen; Wang, Jian-Min; Czerny, Bożena; Chen, Yong-Jie; Songsheng, Yu-Yang; Wang, Yi-Lin; Zhang, Hao; Aceituno, Jesús (December 2024). "B2 1308+326: A Changing-look Blazar or Not?". The Astrophysical Journal. 978 (2): 120. arXiv:2412.10552. doi:10.3847/1538-4357/ad9b7c. ISSN 0004-637X.
- ↑ Puschell, J. J.; Stein, W. A.; Jones, T. W.; Warner, J. W.; Owen, F.; Rudnick, L.; Aller, H.; Hodge, P. (1979-01-01). "B2 1308+326: photometry and polarization during the outburst of 1978 spring". The Astrophysical Journal. 227: L11–L16. Bibcode:1979ApJ...227L..11P. doi:10.1086/182857. ISSN 0004-637X.
- ↑ Li, Shan; Lee, Sang-Sung; Cheong, Whee Yeon (2024-04-11), "A Multi-wavelength Study on A Gamma-ray Bright AGN 1308+326 Using KVN at 22 and 43 GHz", Journal of the Korean Astronomical Society, 57 (1): 67, arXiv:2404.06882, Bibcode:2024JKAS...57...67L, doi:10.5303/JKAS.2024.57.1.67
- ↑ Hulburt, Madeline L.; Choi, Ha-Eun H.; Du, Norah; Balonek, Thomas J.; Corcoran, Riley M.; Slater, John J.; Neal, Warner S.; Malinowski, Chloe R.; Sampson, Matthew J.; Unnone, Victor K.; Heatherton, James F.; Tockstein, Jordan L. (2022-06-01). "Unprecedented Optical Flare Continues in Blazar 1308+326, Reaching Historic Maximum Brightness". The Astronomer's Telegram. 15474: 1. Bibcode:2022ATel15474....1H.
- ↑ Minev, M.; Valcheva, A. (2022-07-01). "B2 1308+326 is dimming after the highest optical state". The Astronomer's Telegram. 15496: 1. Bibcode:2022ATel15496....1M.
- ↑ Otero-Santos, J.; Piirola, V.; Pacciani, L.; Escudero, J.; Agudo, I.; Bonnoli, G.; Morcuende, D.; Casanova, V.; Aceituno, F. J.; Sota, A.; Marchini, A.; Stiaccini, L.; Leonini, S.; Conti, M.; Rosi, P. (2023-12-01). "Optical follow-up of the gamma-ray flare of the blazar OP 313 reveals a bright state with high polarization degree". The Astronomer's Telegram. 16360: 1. Bibcode:2023ATel16360....1O.
- ↑ Airapetyan, E. A; Matveenko, L. I (January 1997). "The fine structure of compact radio sources from geodetic data". Astronomy Letters. 23 (1): 64–70. Bibcode:1997AstL...23...64A.
- ↑ Zavala, R. T.; Taylor, G. B. (2003-05-20). "A View through Faraday's Fog: Parsec-Scale Rotation Measures in Active Galactic Nuclei". The Astrophysical Journal. 589 (1): 126–146. arXiv:astro-ph/0302367. Bibcode:2003ApJ...589..126Z. doi:10.1086/374619. ISSN 0004-637X.
- ↑ Cassaro, P.; Stanghellini, C.; Bondi, M.; Dallacasa, D.; Ceca, R. Della; Zappalà, R. A. (1999-11-01). "Extended radio emission in BL Lac objects - I. The images" (PDF). Astronomy and Astrophysics Supplement Series. 139 (3): 601–616. arXiv:astro-ph/9910209. Bibcode:1999A&AS..139..601C. doi:10.1051/aas:1999511. ISSN 0365-0138.
- ↑ Schramm, K.-J; Borgeest, U.; K¨uhl, D.; von Linde, J.; Linnert, M.D.; Schramm, T. (1994). "The Hamburg Quasar Monitoring Program (HQM) at Calar Alto: III. Lightcurves of optically violent variable sources". Astronomy & Astrophysics Supplement Series. arXiv:astro-ph/9403050. Bibcode:1994astro.ph..3050B.
- ↑ Pyatunina, T. B.; Kudryavtseva, N. A.; Gabuzda, D. C.; Jorstad, S. G.; Aller, M. F.; Aller, H. D.; Teräsranta, H. (2007-09-26). "Frequency-dependent time delays for strong outbursts in selected blazars from the Metsähovi and UMRAO monitoring data bases – II". Monthly Notices of the Royal Astronomical Society. 381 (2): 797–808. Bibcode:2007MNRAS.381..797P. doi:10.1111/j.1365-2966.2007.12281.x. hdl:10468/4979. ISSN 0035-8711.
