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 Today it has been replaced by the UBV photometric system.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

• Photometric system
• Stellar classification

References

Further reading

• C.R. Kitchin (2003). Astrophysical Techniques, Fourth Edition. Taylor & Francis. p. 446. ISBN 978-1-4200-5702-7.

External links

• Schematic images