About Mirfak
Description
Mirfak is a yellow-white supergiant of spectral type F5Ib at magnitude 1.79, the brightest star in Perseus. Located about 510 light-years from Earth, it has a luminosity of roughly 5,000 times solar. Mirfak is the brightest member of the Alpha Persei Cluster (Melotte 20), a nearby open cluster visible to the naked eye.
Observing Tips
Mirfak is the bright star at the center of a scattered group of fainter stars — the Alpha Persei Cluster — which is a magnificent sight in binoculars or a wide-field telescope. The cluster spans several degrees. Mirfak lies between Cassiopeia and the Pleiades. It is circumpolar from many northern latitudes. Best observed October through February.
History
The name Mirfak comes from the Arabic 'mirfaq al-thurayya,' meaning 'the elbow.' In Greek mythology, Perseus used Mirfak's position in the constellation to represent the hero's side as he holds the Gorgon's head. The Alpha Persei Cluster surrounding it was first recognized as a physical group in the early 20th century.
Fun Facts
The Alpha Persei Cluster is one of the best examples of an open cluster whose brightest member is a supergiant. The cluster is about 50 million years old and is slowly dispersing. In binoculars, the spray of blue-white stars around golden Mirfak is one of the loveliest sights in the autumn sky.
Observe
1Physical Properties
2Position & Identifiers
3How easy to spot?
| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | Easy | Easy | Easy |
| 50 mm finder 50mm finder | Easy | Easy | Easy |
| 150 mm telescope 150mm scope | Easy | Easy | Easy |
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
4Visibility
Set a location in User Settings to see visibility data.
5Survey Image
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Explore
7
Size Comparison
8
Compare Stars
9
Spectral Classification
10
Hertzsprung-Russell Diagram
11
Stellar Lifecycle
12
Blackbody Spectrum
13
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
14
Stellar Fusion
Discover
15Stellar Notes
16
Light Travel Time Machine
17
Relativistic Travel
Nearby in the Sky
Other targets within a few degrees — pan your scope a little and keep exploring.
Visibility scores assume a 150 mm Newton at Bortle 4.
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