Technical facts about this news release: About the Object

Object Name: 	Whirlpool Galaxy, M51, NGC 5194/5
Object Description: 	Face-on Spiral Galaxy with Companion
Position (J2000): 	R.A. 13h 29m 52.37s Dec. +47° 11' 40.8"
Constellation: 	Canes Venatici
Distance: 	About 31 million light-years (9.6 million parsecs)
Dimensions: 	This image is 3 arcminutes (20,000 light-years or 6,000 parsecs) wide.

About the Data

Data Description: The Hubble optical image was created from HST data from proposal 10452: S. Beckwith (STScI), R. Kennicutt, Jr. (University of Cambridge), and H. Bond, C. Christian, L. Frattare, F. Hamilton, Z. Levay, M. Mutchler, K. Noll, and T. Royle (Hubble Heritage Team, STScI/AURA). NICMOS observations were made with the HST proposal 10501: R. Chandar (University of Toledo), D. Calzetti (University of Massachusetts), R. Kennicutt, Jr. (University of Cambridge), M. Regan and B. Whitmore (STScI), and E. Schinnerer (Max Planck Institute for Astronomy, Heidelberg).
Instrument: 	NICMOS 
Exposure Date(s): 	November 28 - December 2, 2005 	January 18-22, 2005
Exposure Time: 	9 hours 	9 hours
Filters: 	F160W (J) 	F435W (B), F555W (V), F658N (H-alpha + [N II]), F814W (I)

About the Release

Credit: 	NASA, ESA, M. Regan and B. Whitmore (STScI), and R. Chandar (University of Toledo)
Release Date: 	January 13, 2010
Color: 	This image, which was obtained by aligning data from both the NICMOS and ACS detectors and dividing the NICMOS brightness values by the ACS values, was originally black and white. These brightness values were translated into a range of reddish hues. Such color "maps" can be useful in helping to distinguish subtly varying brightness in an image.