Pottering around in the astronomical garden - paper 5

High proper-motion stars in 2MASS

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Stars with high proper motions are likely to be within 100 pc and many of our nearest neighbours have been first identified through their proper motion.

All the stars having proper motion of >300 mas/yr in either right ascension or declination were extracted from the UCAC3 catalogue. The 2MASS (J-H) and (H-K) magnitudes were calculated for each of the stars and the results presented graphically.

The following points are noteworthy -

1. Red dwarfs are known to be concentrated around (J-H) = 0.6 and (H-K) = 0.25. For the brightest stars in the sample (where J is in the range 6 to 7) the majority of the fastest moving stars do not appear to be M class dwarfs.
2. For the sample where J is in the range 8 to 9 both the number and percentage of red dwarf stars has increased rapidly and this trend continues as ever fainter stars are plotted. When J is 11 to 12 almost all the fastest moving stars are red dwarfs.
3. The horizontal band - best seen in the graph for J = 10 to 11 - corresponds to late F through to late K dwarf stars.
4. The final graph, where J = 12 to 13, continues the trend. The few white dwarf stars appear in the lower left hand corner.

Useful links

"An Infrared High Proper Motion Survey Using 2MASS and SDSS: Discovery of M, L and T Dwarfs" - Link

"The Solar neighbourhood VIII - Discovery of new high proper motion nearby stars ...." - Link

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 Most remain unpublished and this series of papers aims to put them all into the public domain.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 12th 2011.