SDSS J1430+2303
Galaxy with an active nucleus
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SDSS J1430+2303 (or SDSS J143016.05+230344.4) is a galaxy with an active galactic nucleus that has been claimed to be undergoing a periodic brightness variability that is speeding up. One explanation for the purported behavior is that it could be a supermassive black hole binary. Initial trajectory models suggested the pair could be merging either before the end of 2022 or, alternatively, no later than 2025.[1][2]
| SDSS J1430+2303 | |
|---|---|
Sloan Digital Sky Survey image of SDSS J1430+2303. On the left is UGC 9322. | |
| Observation data (J2000 epoch) | |
| Constellation | Boötes |
| Right ascension | 14h 30m 16.04s |
| Declination | +23° 03′ 44.5″ |
| Redshift | 0.08105 |
| Distance | 339 Mpc (1.11 Gly) |
| Characteristics | |
| Type | E/Sy |
| Size | ~130,000 ly (diameter) |
| Apparent size (V) | 0.41 x 0.24 |
| Other designations | |
| PGC 214276, SDSS J143016.05+230344.4, 2MASS J14301603+2303445, HOLM 655C | |
The original claim of periodic variations was made in January 2022 in an unrefereed preprint, posted to the ArXiv server, that has not yet been published in a refereed journal as of early 2023. The discovery team later published X-ray observations of the object, finding evidence of strong X-ray variability on timescales of a few days.[3] However, subsequent follow-up observations by two independent groups did not find evidence of continued periodic brightness variations, casting doubt on the binary black hole hypothesis.[4][5]
Galaxy
SDSS J1430+2303 is a Seyfert 1 galaxy, an elliptical galaxy with a mass of 150 billion solar masses.[2] It forms a triple galaxy system called HOLM 655, alongside UGC 9322 and Markarian 683.[6]
SDSS J1430+2303 is 1.05 × 1022 km from Earth (or 1.11 billion light years, 339 Mpc) with a redshift of 0.08105.[2] It has an Hα line emission, blue-shifted by 2400 km/s, relative to other emission lines from the galaxy.[2]
An estimate of a supermassive black hole at its center is 40 million solar masses.[2]