Cygnus X-1: Still a 'Star' After All Those Years

August 28, 2009
Credits: NASA/CXC

Since its discovery 45 years ago, Cygnus X-1 has been one of the most intensively studied cosmic X-ray sources. About a decade after its discovery, Cygnus X-1 secured a place in the history of astronomy when a combination of X-ray and optical observations led to the conclusion that it was a black hole, the first such identification.

The Cygnus X-1 system consists of a black hole with a mass about 10 times that of the Sun in a close orbit with a blue supergiant star with a mass of about 20 Suns. Gas flowing away from the supergiant in a fast stellar wind is focused by the black hole, and some of this gas forms a disk that spirals into the black hole. The gravitational energy release by this infalling gas powers the X-ray emission from Cygnus X-1.

Although more than a thousand scientific articles have been published on Cygnus X-1, its status as a bright and nearby black hole continues to attract the interest of scientists seeking to understand the nature of and how they affect their environment. Observations with Chandra and ESA's are especially valuable for studying the property of the stellar wind that fuels Cygnus X-1, and determining its rate of spin.

This latter research has revealed that Cygnus X-1 is spinning very slowly. This puzzling result could indicate that Cygnus X-1 may have formed in an unusual type of that somehow prevented the newly formed black hole from acquiring as much spin as other stellar black holes.

Provided by JPL/NASA (news : web)

Explore further: Black Hole Blows Bubble Between The Stars

Related Stories

Black Hole Blows Bubble Between The Stars

August 11, 2005

A team of astronomers from The Netherlands and the UK has discovered a vast "jet-powered bubble" formed in the gas around a black hole in the Milky Way.

Recommended for you

Hubble image: Stormy seas in Sagittarius

July 30, 2015

Some of the most breathtaking views in the Universe are created by nebulae - hot, glowing clouds of gas. This new NASA/ESA Hubble Space Telescope image shows the centre of the Lagoon Nebula, an object with a deceptively tranquil ...

New Horizons data hint at underground ocean

July 30, 2015

Pluto wears its heart on its sleeve, and that has scientists gleaning intriguing new facts about its geology and climate. Recent data from NASA's New Horizons probe—which passed within 7,800 miles of the surface on July ...

Unusual red arcs spotted on icy Saturn moon Tethys

July 30, 2015

Like graffiti sprayed by an unknown artist, unexplained arc-shaped, reddish streaks are visible on the surface of Saturn's icy moon Tethys in new, enhanced-color images from NASA's Cassini spacecraft.

Dense star clusters shown to be binary black hole factories

July 29, 2015

The coalescence of two black holes—a very violent and exotic event—is one of the most sought-after observations of modern astronomy. But, as these mergers emit no light of any kind, finding such elusive events has been ...

4 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Nik_2213
not rated yet Aug 28, 2009
There's lots of scenarios that may spin-up a black-hole progenitor. What will make them spin-down ? Interaction of mag field with surrounds ?
Ashibayai
not rated yet Aug 29, 2009
Tidal deceleration.
Birger
not rated yet Aug 29, 2009
Is the visible component -the blue supergiant- the star known as HDE226868? Or am I confusing X-ray sources?
yyz
not rated yet Aug 30, 2009
@birger, yes, indeed the blue supergiant is a.k.a. HD 226868, V1367 Gyg, BD 35 3815, among many other catalog numbers :)

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.