4C +37.11

Radio galaxy and elliptical galaxy in the constellation Perseus

4C +37.11
Observation data (J2000 epoch)
Constellation	Perseus
Right ascension	04^h 05^m 49.2^s^[1]
Declination	+38° 03′ 32″^[1]
Redshift	16,500 ± 300 km/s^[1]
Distance	750 Mly (230 Mpc) ^[2]
Apparent magnitude (V)	17.2^[1]
Characteristics
Type	Sy^[1]
Other designations
GLXY J0405+380, B2 0402+37, 2MASX J04054928+3803320, RX J0405.8+3803, PGC 2820486

4C +37.11 or Galaxy 0402+379 is a radio galaxy and elliptical galaxy featuring binary supermassive black holes with the least separation of any directly observed binaries, as of 2006. The separation between the two is 24 light-years or 7.3 parsecs, with an orbital period of 30,000 years. The two supermassive black holes, about 750 million light years from earth, have a combined mass of about 15 billion M_☉.^[3]

Other supermassive binary black hole candidates suggest the smaller separation distances expected as they eventually merge, but have not been confirmed. For example, quasar OJ 287 is inferred to have a binary supermassive black hole pair with an orbital period of 12 years, and thus be much closer together. However these have not been directly measured and additional observation, possibly over extended time periods, is needed.

The eventual collision of the pair, which should stay apart for at least a few million more years, would result in strong gravitational waves.^[3]

References

^ ^a ^b ^c ^d ^e "NASA/IPAC Extragalactic Database". Results for 0402+379. Retrieved 26 November 2006.
^ "Scientists Find Closest Pair of Supermassive Black Holes". PhysOrg.com. Retrieved 15 March 2008.
^ ^a ^b Klesman, Alison (29 June 2017). "Astronomers spot a pair of orbiting supermassive black holes". Astronomy Magazine.

VLBA Reveals Closest Pair of Supermassive Black Holes (UNM Today) 2 May 2006
A Compact Supermassive Black-Hole Binary System Archived 16 February 2013 at the Wayback Machine (Los Alamos National Laborator - LANL)

External links

Black Hole Pair Sets Proximity Record (SPACE.com) 1 May 2006 02:04 pm ET
Two black holes come oh-so-close (MSNBC) 5:23 p.m. ET 1 May 2006
Colossal black holes seen in closest clinch yet (New Scientist) 16:02 21 April 2006
A Supermassive Black Hole Pairing (Centauri Dreams)
Scientists Find Closest Pair of Supermassive Black Holes (PhysOrg.com) 1 May 2006
VLBA Reveals Closest Pair of Supermassive Black Holes^{[permanent dead link]} (SpaceRef.com) Monday, 1 May 2006
Closest-spaced giant black hole pair found (SpaceFlight Now) 1 May 2006

Constellation of Perseus

Stars

Bayer	α (Mirfak) β (Algol) γ δ ε ζ η (Miram) θ ι κ (Misam) λ μ ν ξ (Menkib) ο (Atik) π ρ σ τ φ ψ ω b
Flamsteed	1 2 3 4 (g) 5 7 8 9 (i) 10 11 12 14 16 17 20 21 24 29 30 31 32 (l) 34 36 40 (o) 42 (n) 43 (A) 48 (c) 49 50 52 (f) 53 (d) 54 55 56 57 (m) 58 (e) 59 1 Aur
Variable	S T U V X Z RS RT RV RW RY ST SU SV TZ UV UX UY VX XX XY XZ YZ AB AG AR AS AW AX BM DM DY FO GK IK IP IQ IU IW IX IZ KP KS KT KW LX V351 V356 V357 V361 V376 V380 V386 V392 V396 V400 V423 V432 V440 V459 V461 V471 V472 V473 V480 V490 V492 V505 V509 V518 V520 (61 And) V521 V545 V551 V572 V573 V575 V576 V621 V718 V1024
HR	470 526 529 538 540 621 641 787 792 810 820 831 842 846 849 864 865 876 885 886 890 894 918 (k) 920 923 930 949 950 956 964 966 969 973 975 979 986 991 1001 1019 1034 1037 1041 1047 1051 1056 1059 1074 1097 1113 1127 1130 1133 1141 1160 1164 1176 1191 1197 1198 1207 1215 1226 1234 1286 1301 1330 1333 1337 1344 1371 1390 1419 1424 1482 1489 1493 1500 1514
HD	13519 14433 14434 16691 16760 17092 17245 17605 21684 22781 23301 23596 25329 26702 29587
Other	BD+31 643 BD+48 740 G 38-29 G 95-57 GD 61 HAT-P-15 (Berehynia) HAT-P-29 (Muspelheim) IRAS 04296+3429 L1448-IRS2E LkHα 101 LRLL 54361 NGC 1333 13 NGC 1333 IRAS 2A NGC 1333 IRAS 4A NGC 1333 IRAS 4B NGC 1624-2 PSR B0355+54 PSR J0357+3205 WR 4

Exoplanets	WASP-11b/HAT-P-10b

Star
clusters

NGC	869 (h) 884 (χ) 957 1039 1220 1285 1342 1444 1513 1528 1545 1624
Other	Alpha Persei Cluster IC 348 Trumpler 2

Nebulae

NGC	650 (Little Dumbbell Nebula) 1333 1491 1499 (California Nebula) 1579
Other	Barnard 203 Wreath Nebula

Galaxies

NGC	1003 1023 1058 1077 1160 1161 1167 1169 1250 1259 1260 1264 1265 1267 1268 1270 1271 1272 1273 1274 1275 1277 1278 1279 1281 1282 1283 1293 1294 1334
Other	IC 310 UGC 2885 (Godzilla galaxy) 4C +37.11