Cursa — Star in Eridanus
HIP 23875; Beta Eridani; 67 Eridani
About Cursa
Description
Cursa is a white giant of spectral type A3III at magnitude 2.79 in Eridanus. Located about 89 light-years from Earth, it has a luminosity of roughly 55 times solar. Cursa marks the beginning (source) of the long, winding celestial river Eridanus, lying very close to Rigel in Orion.
Observing Tips
Cursa lies just northwest of Rigel, marking where the River Eridanus begins its long southward journey. It is easy to find due to its proximity to Rigel. The river then winds south and west through a succession of fainter stars for over 60 degrees. Best observed December through February.
History
The name Cursa comes from the Arabic 'al-kursi,' meaning 'the chair' or 'the footstool,' possibly referring to its position near Orion's foot. Eridanus is one of the longest constellations, stretching from near the celestial equator all the way south to Achernar near the south celestial pole.
Fun Facts
Cursa is so close to Rigel in the sky (about 3 degrees) that the two stars from very different constellations often appear in the same binocular field — a blue supergiant at 860 light-years paired with a nearby white giant at 89 light-years.
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
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Compare Stars
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Spectral Classification
10
Hertzsprung-Russell Diagram
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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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