North polar sequence
The North polar sequence is a group of 96 stars that was used to define stellar magnitudes and colors.[1] The cluster of stars lies within two degrees of the Northern Celestial pole.[1] That fact makes them visible to everyone in the northern hemisphere.[2]
Originally proposed by Edward Charles Pickering, the system was used between 1900 and 1950. Today it has been replaced by the UBV photometric system.
See also
[edit]References
[edit]- ^ a b "North Polar Sequence - Oxford Reference".
- ^ "eSky: North Polar Sequence". www.glyphweb.com.
Further reading
[edit]- C.R. Kitchin (2003). Astrophysical Techniques, Fourth Edition. Taylor & Francis. p. 446. ISBN 978-1-4200-5702-7.
External links
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