Alternate Names

Nova Ophiuchi 1977, V2107 Ophiuchi, XN Oph77

Type

Stellar mass

Location

In the constellation Ophiuchus

Distance

27,000 light-years

Mass

5 to 7 times the mass of the Sun

Size

Diameter roughly 20 miles (35 km), equal to the size of a large city

Discovery Methods

• Detection of an accretion disk
• Measuring the motions of a companion star

H1705-25

Artist's concept of an X-ray binary consisting of a fairly small, low-mass star and a black hole. The black hole is encircled by a disk of hot gas, while jets of charged particles shoot into space from the black hole's poles.

Artist's concept of an X-ray binary system like H1705-25. The companion star, at left, is so close that it dumps gas toward the black hole, forming a hot accretion disk. The disk is color coded to show temperature, with orange the coolest and blue and white the hottest.

Artist's concept shows the H1705-25 system.

This document was last modified: March 29, 2011.