HD 221525

HD 221525

Location of HR 8938 (circled)
Observation data Epoch J2000.0 [1]      Equinox J2000.0 [1]
Constellation	Cepheus[2]
Right ascension	23^h 27^m 00.85^s [1]
Declination	87° 18′ 27.02″ [1]
Apparent magnitude (V)	5.56 [1]
Characteristics
Spectral type	A7IV[1]
Astrometry
Radial velocity (Rv)	-10.9[1] km/s
Parallax (π)	9.79 ± 0.35[1] mas
Distance	330 ± 10 ly (102 ± 4 pc)
Absolute magnitude (MV)	0.61[3]
Details
Mass	2.25?[2] M☉
Radius	3.5[2] R☉
Luminosity	44[2] L☉
Temperature	8000[2] K
Age	~900 million[2] years
Other designations
HD 221525, HIP 115746, HR 8938

HD 221525 is a subgiant star near the north celestial pole in the constellation Cepheus.^[2] At an apparent magnitude of 5.6, it can be seen with the naked eye under dark skies.^[1] It is about 30 times fainter than the star Polaris.^{[NB 1]}

HR 8938 is located directly below Polaris on this chart.

Notes

1. Calculation: $(\sqrt[5]{100})^{5.56-1.97}\approx 27.2$

References

1. "HR 8938". SIMBAD Astronomical Database. Retrieved 2012-03-02.
2. Jim Kaler. "HR 306 and HR 8938". Stars.astro.illinois.edu. Retrieved 2012-02-29.
3. Jim Kaler. "The Polar Project". University of Illinois. Retrieved 2012-05-02.

External links

• Labelled image of the region around HR 8938.
• HD 221525 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images

See also

• HR 8938 Cephei, Deadmau5 song named after the star