Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2002 August 3
See Explanation.  Clicking on the picture will download
 the highest resolution version available.

The Galactic Centre - A Radio Mystery
Credit: N. E. Kassim, D. S. Briggs, T. J. W. Lazio, T. N. LaRosa, J. Imamura (NRL/RSD)

Explanation: Tuning in to the centre of our Milky Way galaxy, radio astronomers explore a complex, mysterious place. A premier high resolution view, this startlingly beautiful picture covers a 4x4 degree region around the galactic centre. It was constructed from 1 metre wavelength radio data obtained by telescopes of the Very Large Array near Socorro, New Mexico, USA. The galactic centre itself is at the edge of the extremely bright object labeled Sagittarius (Sgr) A, suspected of harbouring a million solar mass black hole. Along the galactic plane which runs diagonally through the image are tortured clouds of gas energized by hot stars and bubble-shaped supernova remnants (SNRs) - hallmarks of a violent and energetic cosmic environment. But perhaps most intriguing are the arcs, threads, and filaments which abound in the scene. Their uncertain origins challenge present theories of the dynamics of the galactic centre.

Tomorrow's picture: grand design

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
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& Michigan Tech. U.