# B2 1420+32

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/B2_1420%2B32
> Markdown URL: https://mediated.wiki/source/B2_1420%2B32.md
> Source: https://en.wikipedia.org/wiki/B2_1420%2B32
> Source revision: 1348350800
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

Quasar in the constellation of Boötes

B2 1420+32 SDSS image of B2 1420+32 (located center) Observation data (J2000.0 epoch) Constellation Boötes Right ascension 14h 22m 30.380s Declination +32° 23′ 10.440″ Redshift 0.682 Heliocentric radial velocity 143,130 km/s Distance 6.3 billion light years Apparent magnitude (V) 19.16 Characteristics Type FSRQ Other designations FBQS J1422+3223, 6C 142016+323628, OHIO Q 334, QSO B1420+326, 7C 142021.30+323647.00, RX J1422.5+3223, NVSS J142230+322309, PGC 4066234

**B2 1420+32** also known as **OQ 334** and **QSO B1420+326**, is a [flat-spectrum radio quasar](/source/Flat-spectrum_radio_quasar)[1] in the constellation of [Boötes](/source/Bo%C3%B6tes). Its [redshift](/source/Redshift) is estimated as (z) 0.682 corresponding to a light travel time of 6.3 billion light years[2] and was first detected in March 1973 as a blue stellar object.[3] This object gained significant attention because of its renewed flaring activity, categorized as changing looking [blazar](/source/Blazar) and is the fourth known distant object displaying very high energy [radio emission](/source/Radio_wave).

## Description

B2 1420+32 is extremely variable on an [electromagnetic spectrum](/source/Electromagnetic_spectrum). A known blazar, it is shown to undergo extreme [gamma-ray](/source/Gamma_ray) activity in 2018 after a ten-year quiescent period, displaying a three-day flux of 4.79 ± 0.59 averaging a photon index of 1.96 ± 0.10.[4] The same year in December, it reached a daily average gamma-ray flux of 1.3 ± 0.2 × 10−6 [photons](/source/Photon) cm−2 s−1, making it 180 times greater than its observed flux in the four year observation period.[5] On December 30 and 31 in 2019, the fluxes were estimated to be 0.9 ± 0.1 × 10−6 photons cm−2 s−1 and 1.7 ± 0.2 × 10−6 photons cm−2 s−1.[6] Two near-infrared flares were observed from the object displaying a [K-band](/source/K_band_(infrared)) flux of 14.28 ± 0.05 on June 27, 2019, and [H-band](/source/H_band_(infrared)) flux of 12.14 ± 0.03 on March 31, 2023.[7][8]

During the first month of 2020, B2 1420+32 underwent a high energy powerful gamma-ray flare,[9][10][11] with its radio emission noted as increasing by February.[12] In July 2021, it again underwent a flaring period, detected by astronomers at 14 and 7 [milliammeter](/source/Ammeter) bands, who happened to observe it as part of the TELAMON program.[13] Raj Prince noted one of the peaks during its flaring state display the highest known gamma-ray photon level at 77 GeV, indicating the emitting region is either situated on the broad-line region outer boundary or at the [torus](/source/Torus) inner edge.[4] DCF analysis, would find the time lags of its light curve is 1.69 days.[14]

Additionally to its extreme gamma-ray activity, B2 1420+32 has optical variability.[15] As detected on July 30 2021, astronomers from the [Crimean Astrophysical Observatory](/source/Crimean_Astrophysical_Observatory) noted its increasing activity with an [R-band](/source/R_band) magnitude of 15.156; it previously had an R-band magnitude of 15.50 the previous night.[16] A year later on July 31, 2022, it reached 16.13.[17] The [linear polarization](/source/Linear_polarization) levels also increased from 27.5% to 33.5% in 2021 but decreased to 22.5% in 2022.[16][17]

The nucleus of B2 1420+32 is constantly [active](/source/Active_galactic_nucleus) due to a presence of its [accretion disk](/source/Accretion_disk) around its [supermassive black hole](/source/Supermassive_black_hole). The black hole in the center of the object, is estimated to be 4 × 108 *[M☉](/source/Solar_mass)* based on a virial-based scaling relationship with an accretion disk luminosity of 2 × 1018 erg s−1.[18][11]

The active galactic nucleus (AGN) of B2 1420+32 can be described as change looking, marked by a series of changes in spectral variability and broad [emission lines](/source/Spectral_line). The object is categorized as a flat-spectrum (FSRQ) radio quasar, but flaring activity occurring in January 2018 lead the observers to reclassify it as a [BL Lacertae object](/source/BL_Lacertae_object) (BL Lac).[19][20] However 96 days later, it has since reverted to back to its original classification of an FSRQ, but since changed again to its BL Lac state after 416 days in July 2019 and so on.[21][22][23] This is suggested by changes in its [accretion](/source/Accretion_(astrophysics)) mode but was later revealed the [jet](/source/Astrophysical_jet) of B2 1420+32 actually influenced the change in its continuum flux, thus the change of classification between FSRQ and BL Lac.[21][20]

Polarized intensity radio mapping by [Very Long Baseline Array](/source/Very_Long_Baseline_Array), have showed the source of B2 1420+32 is made up of a bright single radio core situated at the jet's northwestern end, with a weaker extended jet feature located at a position angle of 130°. There is a polarized feature interpreted as a jet knot shown separating from the core. Linear approximation has found the knot is moving at [superluminal motion](/source/Superluminal_motion) at speeds of 12.0 ± 1.7c and happens to be ejecting. The polarization direction close to the direction of the jet also suggested the knot might be interpreted as a [moving shock](/source/Moving_shock).[11]

## References

1. **[^](#cite_ref-1)** ["Multi-band optical observations of the flaring blazar OQ 334 (B2 1420+326) with the new 50cm robotic telescope at IAO"](https://www.astronomerstelegram.org/?read=16782). *The Astronomer's Telegram*. Retrieved 2025-07-14.

1. **[^](#cite_ref-2)** Marchini, Alessandro; Bonnoli, Giacomo; Bellizzi, Lorenzo; Millucci, Vincenzo; Paoletti, Riccardo; Stiaccini, Leonardo; Truzzi, Stefano; Ventura, Sofia; Conti, Massimo; Vallerani, Claudio (July 2019). ["The flaring blazar B2 1420+32 below R=14"](https://ui.adsabs.harvard.edu/abs/2019ATel12914....1M/abstract). *The Astronomer's Telegram*. **12914**: 1. [Bibcode](/source/Bibcode_(identifier)):[2019ATel12914....1M](https://ui.adsabs.harvard.edu/abs/2019ATel12914....1M).

1. **[^](#cite_ref-3)** Bergamini, R.; Bracessi, A.; Colla, G.; Fanti, C.; Ficarra, A.; Formiggini, L.; Gandolfi, E.; Gioia, I.; Lari, C.; Marano, B.; Padrielli, L.; Tomasi, P.; Vigotti, M. (March 1973). ["Optical Identifications of Ra- diosources from the B 2 Catalogue. Quasi Stellar Sources"](https://articles.adsabs.harvard.edu/pdf/1973A%26A....23..195B). *Astronomy and Astrophysics*. **23**: 195. [Bibcode](/source/Bibcode_(identifier)):[1973A&A....23..195B](https://ui.adsabs.harvard.edu/abs/1973A&A....23..195B). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. ^ [***a***](#cite_ref-:0_4-0) [***b***](#cite_ref-:0_4-1) Prince, Raj; Khatoon, Rukaiya; Stalin, C. S. (April 2021). ["Broad-band study of OQ 334 during its flaring state"](https://doi.org/10.1093%2Fmnras%2Fstab369). *Monthly Notices of the Royal Astronomical Society*. **502** (4): 5245–5258. [arXiv](/source/ArXiv_(identifier)):[2102.03516](https://arxiv.org/abs/2102.03516). [doi](/source/Doi_(identifier)):[10.1093/mnras/stab369](https://doi.org/10.1093%2Fmnras%2Fstab369). [ISSN](/source/ISSN_(identifier)) [0035-8711](https://search.worldcat.org/issn/0035-8711).

1. **[^](#cite_ref-5)** Ciprini, Stefano (December 2018). ["Fermi LAT detection of a GeV gamma-ray flare from blazar OQ 334 (B2 1420+32)"](https://www.astronomerstelegram.org/?read=12277). *The Astronomer's Telegram*. **12277**: 1. [Bibcode](/source/Bibcode_(identifier)):[2018ATel12277....1C](https://ui.adsabs.harvard.edu/abs/2018ATel12277....1C).

1. **[^](#cite_ref-6)** Malik, Zahoor; Akbar, Sikandar; Shah, Zahir; Misra, Ranjeev; Dar, Athar A; Manzoor, Aaqib; Ahanger, Sajad; Nazir, Zeeshan; Iqbal, Naseer; Rubab, Seemin; Tantry, Javaid (2025-04-15). ["Statistical Insights into flux and photon index distributions of VHE FSRQs from *Fermi*-LAT observations"](https://doi.org/10.1093%2Fmnras%2Fstaf620). *Monthly Notices of the Royal Astronomical Society*. **539** (3): 2185–2201. [doi](/source/Doi_(identifier)):[10.1093/mnras/staf620](https://doi.org/10.1093%2Fmnras%2Fstaf620). [ISSN](/source/ISSN_(identifier)) [0035-8711](https://search.worldcat.org/issn/0035-8711).

1. **[^](#cite_ref-7)** ["A New Large NIR Flare of the blazar HB891420+326"](https://www.astronomerstelegram.org/?read=12866). *The Astronomer's Telegram*. Retrieved 2025-07-14.

1. **[^](#cite_ref-8)** Carrasco, L.; Escobedo, G.; Porras, A.; Recillas, E.; Felix, L. (April 2023). ["New Giant NIR flare of the FSRQ HB891420+326"](https://ui.adsabs.harvard.edu/abs/2023ATel16021....1C/abstract). *The Astronomer's Telegram*. **16021**: 1. [Bibcode](/source/Bibcode_(identifier)):[2023ATel16021....1C](https://ui.adsabs.harvard.edu/abs/2023ATel16021....1C).

1. **[^](#cite_ref-9)** ["Detection of very-high-energy gamma-ray emission from B2 1420+32 with the MAGIC telescopes"](https://www.astronomerstelegram.org/?read=13412). *The Astronomer's Telegram*. Retrieved 2025-07-14.

1. **[^](#cite_ref-10)** ["A strong optical flaring from the Seyfert 1 Galaxy OQ 334 (B2 1420+326)"](https://www.astronomerstelegram.org/?read=16681). *The Astronomer's Telegram*. Retrieved 2025-07-14.

1. ^ [***a***](#cite_ref-:1_11-0) [***b***](#cite_ref-:1_11-1) [***c***](#cite_ref-:1_11-2) Acciari, V. A.; Ansoldi, S.; Antonelli, L. A.; Engels, A. Arbet; Artero, M.; Asano, K.; Baack, D.; Babić, A.; Baquero, A.; Almeida, U. Barres de; Barrio, J. A.; González, J. Becerra; Bednarek, W.; Bellizzi, L.; Bernardini, E. (2021-03-01). ["VHE gamma-ray detection of FSRQ QSO B1420+326 and modeling of its enhanced broadband state in 2020"](https://www.aanda.org/articles/aa/abs/2021/03/aa39687-20/aa39687-20.html). *Astronomy & Astrophysics*. **647**: A163. [arXiv](/source/ArXiv_(identifier)):[2012.11380](https://arxiv.org/abs/2012.11380). [Bibcode](/source/Bibcode_(identifier)):[2021A&A...647A.163M](https://ui.adsabs.harvard.edu/abs/2021A&A...647A.163M). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202039687](https://doi.org/10.1051%2F0004-6361%2F202039687). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. **[^](#cite_ref-12)** ["Continuing flux density increase in OQ 334 revealed by Sardinia Radio Telescope dual-frequency observations"](https://www.astronomerstelegram.org/?read=13582). *The Astronomer's Telegram*. Retrieved 2025-07-14.

1. **[^](#cite_ref-13)** ["Radio Flaring of the Quasar B2 1420+32"](https://www.astronomerstelegram.org/?read=14822). *The Astronomer's Telegram*. Retrieved 2025-07-14.

1. **[^](#cite_ref-14)** Xiao, Hu-Bing; Cao, Hai-Tao; Xue, Rui; Cai, Jin-Ting; Wang, Ge-Ge; Manganaro, Marina; Zhang, Shao-Hua; Ouyang, Zhi-Hao; Fu, Li-Ping; Fan, Jun-Hui (2024-05-28). ["Probing the Gamma-Ray Emission Region of Five TeV Flat Spectrum Radio Quasars"](https://doi.org/10.1088%2F1674-4527%2Fad420e). *Research in Astronomy and Astrophysics*. **24** (6): 065013. [Bibcode](/source/Bibcode_(identifier)):[2024RAA....24f5013X](https://ui.adsabs.harvard.edu/abs/2024RAA....24f5013X). [doi](/source/Doi_(identifier)):[10.1088/1674-4527/ad420e](https://doi.org/10.1088%2F1674-4527%2Fad420e). [ISSN](/source/ISSN_(identifier)) [1674-4527](https://search.worldcat.org/issn/1674-4527).

1. **[^](#cite_ref-15)** ["ASAS-SN Discovery of an Unprecedented >2 Magnitude Optical Flare from QSO B2 1420+32"](https://www.astronomerstelegram.org/?read=11110). *The Astronomer's Telegram*. Retrieved 2025-07-14.

1. ^ [***a***](#cite_ref-:2_16-0) [***b***](#cite_ref-:2_16-1) ["B2 1420+32 is in high optical and polarization state"](https://www.astronomerstelegram.org/?read=14819). *The Astronomer's Telegram*. Retrieved 2025-07-14.

1. ^ [***a***](#cite_ref-:3_17-0) [***b***](#cite_ref-:3_17-1) ["B2 1420+32 is brightening in optical"](https://www.astronomerstelegram.org/?read=15534). *The Astronomer's Telegram*. Retrieved 2025-07-14.

1. **[^](#cite_ref-18)** Brotherton, Michael S.; Singh, Vikram; Runnoe, Jessie (2015-12-21). ["Orientation and quasar black hole mass estimation"](https://doi.org/10.1093%2Fmnras%2Fstv2186). *Monthly Notices of the Royal Astronomical Society*. **454** (4): 3864–3871. [arXiv](/source/ArXiv_(identifier)):[1509.06468](https://arxiv.org/abs/1509.06468). [doi](/source/Doi_(identifier)):[10.1093/mnras/stv2186](https://doi.org/10.1093%2Fmnras%2Fstv2186). [ISSN](/source/ISSN_(identifier)) [0035-8711](https://search.worldcat.org/issn/0035-8711).

1. **[^](#cite_ref-19)** Mishra, Hora D.; Dai, Xinyu; Chen, Ping; Cheng, Jigui; Jayasinghe, T.; Tucker, Michael A.; Vallely, Patrick J.; Bersier, David; Bose, Subhash; Do, Aaron; Dong, Subo; Holoien, Thomas W.-S.; Huber, Mark E.; Kochanek, Christopher S.; Liang, Enwei (2021-06-01). ["The Changing-look Blazar B2 1420+32"](https://doi.org/10.3847%2F1538-4357%2Fabf63d). *The Astrophysical Journal*. **913** (2): 146. [arXiv](/source/ArXiv_(identifier)):[2103.08707](https://arxiv.org/abs/2103.08707). [Bibcode](/source/Bibcode_(identifier)):[2021ApJ...913..146M](https://ui.adsabs.harvard.edu/abs/2021ApJ...913..146M). [doi](/source/Doi_(identifier)):[10.3847/1538-4357/abf63d](https://doi.org/10.3847%2F1538-4357%2Fabf63d). [ISSN](/source/ISSN_(identifier)) [0004-637X](https://search.worldcat.org/issn/0004-637X).

1. ^ [***a***](#cite_ref-:4_20-0) [***b***](#cite_ref-:4_20-1) Nowakowski, Tomasz; Phys.org. ["B2 1420+32 is a changing-look blazar, study finds"](https://phys.org/news/2021-03-b2-changing-look-blazar.html). *phys.org*. Retrieved 2025-07-14.

1. ^ [***a***](#cite_ref-:5_21-0) [***b***](#cite_ref-:5_21-1) Ren, S. S.; Zhou, R. X.; Zheng, Y. G.; Kang, S. J.; Wu, Q. (2024-05-01). ["The Fermi-LAT view of the changing-look blazar OQ 334"](https://www.aanda.org/articles/aa/abs/2024/05/aa47312-23/aa47312-23.html). *Astronomy & Astrophysics*. **685**: A140. [arXiv](/source/ArXiv_(identifier)):[2402.17099](https://arxiv.org/abs/2402.17099). [Bibcode](/source/Bibcode_(identifier)):[2024A&A...685A.140R](https://ui.adsabs.harvard.edu/abs/2024A&A...685A.140R). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202347312](https://doi.org/10.1051%2F0004-6361%2F202347312). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. **[^](#cite_ref-22)** Chand, Krishan; Gopal-Krishna (2025-05-15). ["The alternating 'changing-look' blazar OQ 334 (B2 1420+32): new observational clues to the blazar state transitions"](https://doi.org/10.1093%2Fmnrasl%2Fslaf053). *Monthly Notices of the Royal Astronomical Society: Letters*. **541** (1): L52–L57. [doi](/source/Doi_(identifier)):[10.1093/mnrasl/slaf053](https://doi.org/10.1093%2Fmnrasl%2Fslaf053). [ISSN](/source/ISSN_(identifier)) [1745-3925](https://search.worldcat.org/issn/1745-3925).

1. **[^](#cite_ref-23)** Ren, S. S.; Zhou, R. X.; Zheng, Y. G.; Kang, S. J. (2024-11-01). ["The Oscillation in Evolution of Changing-look Blazar OQ 334"](https://doi.org/10.3847%2F1538-4357%2Fad83ce). *The Astrophysical Journal*. **976** (1): 124. [arXiv](/source/ArXiv_(identifier)):[2411.08313](https://arxiv.org/abs/2411.08313). [Bibcode](/source/Bibcode_(identifier)):[2024ApJ...976..124R](https://ui.adsabs.harvard.edu/abs/2024ApJ...976..124R). [doi](/source/Doi_(identifier)):[10.3847/1538-4357/ad83ce](https://doi.org/10.3847%2F1538-4357%2Fad83ce). [ISSN](/source/ISSN_(identifier)) [0004-637X](https://search.worldcat.org/issn/0004-637X).

## External links

- [SIMBAD database for B2 1420+32](http://simbad.u-strasbg.fr/simbad/sim-id?Ident=ICRF%20J142230.3%2B322310)

- [HyperLeda Database for B2 1420+32 (PGC = 4066234)](http://atlas.obs-hp.fr/hyperleda/ledacat.cgi?o=B2%201420%2B32)

v t e Constellation of Boötes Boötes in Chinese astronomy Boötes Void List of stars in Boötes Stars Bayer α (Arcturus) β (Nekkar) γ (Seginus) δ (Qigong) ε (Izar, Pulcherrima) ζ η (Muphrid) θ ι κ λ (Xuange) μ1 (Alkalurops) μ2 ν1 ν2 ξ ο π ρ (Kalasungsang) σ (Genghe) τ (Tepiamenit) υ φ χ ψ ω Flamsteed 1 2 3 6 (e) 7 9 10 11 12 (d) 13 14 15 18 20 22 (f) 24 (g) 26 31 32 33 34 (Alrumh) 38 (Merga) 39 40 44 (Quadrans) 45 (c) 46 (b) 47 (k) 50 Variable R S T RX ZZ AB BL BP BX BY CE CH CI CN CP CR CX CY (101 Vir) DE EK HN HP HD 118508 118889 122563 125040 125351 (A) 125658 126128 126129 126141 126200 126271 127304 127334 127726 128093 128198 129132 129357 130084 130603 130917 131040 131473 131496 (Arcalís) 132029 132406 132563 134064 134335 135438 135530 135944 141399 Other 2MASS J15031961+2525196 CFBDSIR 1458+10 Gliese 526 HAT-P-4 LHS 2924 PSR J1544+4937 SDSS J1416+1348 SDSS J1433+1011 TVLM 513-46546 WASP-14 WD 1425+540 ZTF J153932.16+502738.8 Exoplanets HAT-P-4b HD 128311 b c HD 132406 b HD 136418 b (Awasis) τ Boötis b TOI-1853 b WASP-14b Star clusters NGC 5466 Galaxies NGC 5008 5248 5251 5416 5490 5500 5504 5508 5514 5523 5529 5532 5533 5535 5539 5541 5544 5545 5548 5557 5559 5562 5579 5582 5591 5601 5603 5609 5613 5614 5615 5624 5629 5630 5641 5642 5653 5665 5676 5681 5682 5683 5698 5714 5722 5752 5753 5754 5755 5772 5778 5784 5790 5820 5821 5829 5837 5857 5875 5876 5886 5888 5896 5929 5930 5966 Numbered I II III Other 3C 295 3C 299 3C 300 3C 303 3C 315 4C 19.44 4C +26.42 7C 1354+2552 Abell 2009 BCG Arp 302 B2 1420+32 B2 1441+26 CEERS-2112 CEERS-93316 CEERS2-588 CLASS B1359+154 Cloverleaf quasar DDO 190 EGS-zs8-1 EGS-z11-R0 EGSY8p7 H1426+428 IC 4397 IC 4461 IC 4462 IC 4481 IC 4516 IRAS 13349+2438 IRAS 14394+5332 IRAS 15206+3342 LEDA 2108986 MACS 1423-z7p64 MACS J1447.4+0827 BCG Maisie's Galaxy Markarian 463 Markarian 471 Markarian 478 MS 1455.0+2232 BCG MS 1512-cB58 NVSS J141343+433945 OQ 172 OQ 530 PG 1411+442 PG 1543+489 PGC 93125 PGC 1470080 PKS 1345+125 PKS 1413+135 QSO B1422+202 RBS 1467 RGZ J145001.5+144747 RGZ J145039.8+441829 SBS 1415+437 SDSS J135646.10+102609.0 SDSS J1430+2303 Teacup galaxy UGC 8669 UGC 9128 UGC 9425 UGC 9684 UGC 9796 ULAS J1342+0928 VV 191 Galaxy clusters Abell 1795 Abell 1991 BoRG-58 IDCS J1426.5+3508 Astronomical events GRB 990123 GRB 080319B SCP 06F6 SN 2003fg SN 2005bc SN 2020tlf Category

---
Adapted from the Wikipedia article [B2 1420+32](https://en.wikipedia.org/wiki/B2_1420%2B32) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/B2_1420%2B32?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.