Credit: NASA/JPL-Caltech/R. Kennicutt (University of Arizona) and the SINGS Team

Spitzer Turns Two

On August 25, 2003, NASA's Spitzer Space Telescope blasted into the same dark skies it now better understands. In just two years, the observatory's infrared eyes have uncovered a hidden universe teeming with warm stellar embryos, chaotic planet-forming disks, and majestic galaxies, including the delightfully odd galaxy called NGC 4725 shown here.

This peculiar galaxy is thought to have only one spiral arm. Most spiral galaxies have two or more arms. Astronomers refer to NGC 4725 as a ringed barred spiral galaxy because a prominent ring of stars encircles a bar of stars at its center (the bar is seen here as a horizontal ridge with faint red features). Our own Milky Way galaxy sports multiple arms and a proportionally smaller bar and ring.

In this false-color Spitzer picture, the galaxy's arm is highlighted in red, while its center and outlying halo are blue. Red represents warm dust clouds illuminated by newborn stars, while blue indicates older, cooler stellar populations. The red spokes seen projecting outward from the arm are clumps of stellar matter that may have been pushed together by instable magnetic fields.

NGC 4725 is located 41 million light-years away in the constellation Coma Berenices.

This picture is composed of four images taken by Spitzer's infrared array camera at 3.6 (blue), 4.5 (green), 5.8 (red), and 8.0 (red) microns. The contribution from starlight (measured at 3.6 microns) has been subtracted from the 5.8- and 8-micron images to enhance the visibility of the dust features.

About the Object	Object Name: NGC 4725 Object Type: Spiral Galaxy Position (J2000): RA: 12h50m26.6s Dec: +25d30m03s (J2000) Distance: 12.6 million parsecs; 41 million light years Constellation: Coma Berenices
About the Data	Image Credit: NASA/JPL-Caltech/R. Kennicutt (University of Arizona) and the SINGS Team Instrument: IRAC Wavelength: 3.6 (blue), 4.5 (green), 5.8-8.0 (red) microns Field of View: 12.2 x 12.2 arcmin Orientation: North is 55 deg CCW from up Release Date: 25 August 2005
Observers	Robert Kennicutt, Principal Investigator (Steward Observatory, University of Arizona) Lee Armus (Spitzer Science Center, Caltech) Brent Buckalew (Caltech) George Bendo (Steward Observatory, University of Arizona) Daniela Calzetti (Space Telescope Science Institute) Daniel Dale (University of Wyoming) Bruce Draine (Princeton University) Charles Engelbracht (Steward Observatory, University of Arizona) Karl Gordon (Steward Observatory, University of Arizona) George Helou (Caltech) David Hollenbach (NASA Ames Research Center) Thomas Jarrett (Caltech) Lisa Kewley (University of Hawaii) Claus Leitherer (Space Telescope Science Institute) Aigen Li (University of Missouri-Columbia) Sangeeta Malhotra (Space Telescope Science Institute) Helene McLaughlin (Space Telescope Science Institute) Martin Meyer (Space Telescope Science Institute) Eric Murphy (Yale University) Michael Regan (Space Telescope Science Institute) George Rieke (Steward Observatory, University of Arizona) Marcia Rieke (Steward Observatory, University of Arizona) Hélène Roussel (Spitzer Science Center, Caltech) Kartik Sheth (Caltech) John-David Smith (Steward Observatory, University of Arizona) Michele D. Thornley (Bucknell University, Space Telescope Science Institute) Fabian Walter (MPIA Heidelberg)

The Spitzer Space Telescope is a NASA mission managed by the Jet Propulsion Laboratory. This website is maintained by the Spitzer Science Center, located on the campus of the California Institute of Technology and part of NASA's Infrared Processing and Analysis Center.