Berkeley 87

Berkeley 87 is an open cluster in a heavily obscured region of the Milky Way in Cygnus.^[2] The rare WO type Wolf–Rayet star WR 142 is a member of Berkeley 87.^[3]

Berkeley 87
Observation data (J2000 epoch)
Right ascension	20h 21m 43.01s[1]
Declination	+37° 22′ 13.8″[1]
Distance	~1650 pc
Apparent dimensions (V)	8
Physical characteristics
Other designations	Dolidze 7, OCl 161, C 2019+372, OCISM 34, MWSC 3325
Associations
Constellation	Cygnus
See also: Open cluster, List of open clusters

This cluster contains HD 229059 which, as of August 2021, is the nearest known star to Earth with a bolometric luminosity greater than 1 million L_☉.^{[citation needed]}

Prominent stars^[4]

Star name	Effective temperature	Absolute magnitude	Bolometric magnitude	Mass (M☉)	Spectral type
WR 142 (Berkeley 87–29)	200000 K	-3.13	-10.1	28.6	WO2
HD 229059 (Berkeley 87–3)	26300 K	-7.7	-10.3	69	B1Ia
Berkeley 87-25	35700 K	-5.6	-9.1	39	O8.5III
Berkeley 87-15	37800 K	-5	-8.6	34	B[e]
Berkeley 87-4	29500 K	-5	-7.9	23	B0.2III

See also

• List of most massive stars