Pottering around in the astronomical garden - paper 3

Colour-colour diagrams and the hunt for outliers in the Wide-field Infrared Survey Explorer Preliminary Data Release

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Details of the sample studied in this analysis

• Photometric quality = AAAA
• Number of components used in profile fitting = 1
• No image artifacts
• Morphology consistent with a point source
• Unsaturated and reliable detections - magnitude range (8.0, 7.0, 4.0, 0.0) and (15.6, 14.3, 10.2 and 6.5)

The 1988 paper by Bessell and Brett "JHKLM photometry - Standard systems, passbands, and intrinsic colors" describes how to distinguish between red dwarfs and red giants based on differences in the 2MASS (J-H) v (H-K) colour space related to water absorption in their atmospheres.

Colour-colour graphs were generated for all red gaints and red dwarfs identified in the sample. The two graphs are not nearly as different as I had expected them to be and (W2-W3) v (W1-W2) could not be used to distinguish between the two types.

Red Giants

Red Dwarfs

This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration

Important Note

Over the last few years I have carried out many astronomical data mining or data analysis projects. Most remain unpublished and this series of papers aims to put them all into the public domain. I welcome constructive feedback from readers and encourage colleagues to take the work forward, perhaps as far as peer reviewed publication. I can be contacted by email. and this address is monitored daily.

Martin Piers Nicholson - Shropshire, United Kingdom.

This page was last updated on July 8th 2011.