**Not a Moment Wasted**

by Dr. Tony Phillips

The Ring Nebula. Check. M13. Check. Next up: The Whirlpool galaxy.

You punch in the coordinates and your telescope takes off, slewing
across the sky. You tap your feet and stare at the stars. These Messier
marathons would go much faster if the telescope didn't take so long to
slew. What a waste of time!

Don't tell that to the x-ray astronomers.

"We're putting our slew time to good use," explains Norbert Schartel,
project scientist for the European Space Agency's XMM-Newton x-ray
telescope. The telescope, named for Sir Isaac Newton, was launched into
Earth orbit in 1999. It's now midway through an 11-year mission to study
black holes, neutron stars, active galaxies and other violent denizens
of the Universe that show up particularly well at x-ray wavelengths.

For the past four years, whenever XMM-Newton slewed from one object to
another, astronomers kept the telescope's cameras running, recording
whatever might drift through the field of view. The result is a stunning
survey of the heavens covering 15% of the entire sky.

Sifting through the data, ESA astronomers have found entire clusters of
galaxies unknown before anyone started paying attention to "slew time."
Some already-known galaxies have been caught in the act of flaring---a
sign, researchers believe, of a central black hole gobbling matter from
nearby stars and interstellar clouds. Here in our own galaxy, the 20,000
year old Vela supernova remnant has been expanding. XMM-Newton has
slewed across it many times, tracing its changing contours in exquisite
detail.

The slew technique works because of XMM-Newton's great sensitivity. It
has more collecting area than any other x-ray telescope in the history
of astronomy. Sources flit through the field of view in only 10 seconds,
but that's plenty of time in most cases to gather valuable data.

The work is just beginning. Astronomers plan to continue the slew
survey, eventually mapping as much as 80% of the entire sky. No one
knows how many new clusters will be found or how many black holes might
be caught gobbling their neighbors. One thing's for sure: "There *will*
be new discoveries," says Schartel.

Tap, tap, tap. The next time you're in the backyard with your telescope,
and it takes off for the Whirlpool galaxy, don't just stand there. Try
to keep up with the moving eyepiece. Look, you never know what might
drift by.

See some of the other XMM-Newton images at http://sci.esa.int . For more
about XMM-Newton's Education and Public Outreach program, including
downloadable classroom materials, go to http://xmm.sonoma.edu. Kids can
learn about black holes and play "Black Hole Rescue" at The Space Place,
http://spaceplace.nasa.gov/, under "Games."

This article was provided by the Jet Propulsion Laboratory, California
Institute of Technology, under a contract with the National Aeronautics
and Space Administration.

![](media/image1.jpeg){width="6.0in" height="4.2555555555555555in"}

Caption:

*The image on the left is the Vela Supernova Remnant as imaged in X-rays
by ROSAT. On the right are some of the slew images obtained by
XMM-Newton in its "spare" time.*

*Note to editor:*

This image may be downloaded from
<http://spaceplace.nasa.gov/news_images/xmm_vela_supernova.jpg>