Epsilon Coronae Borealis — Star in Corona Borealis
Observe
1Physical Properties
Magnitude
4.15
Spectral Type
K2IIIab
bright giant
Star Color
Red
(B-V 1.23)
Distance
136 ly
2Position & Identifiers
RA
15h 57m 35.3s
Dec
+26° 52' 40.0"
Constellation
Corona Borealis
(CrB)
HR
5947
HIP
78159
HD
143107
SAO
84098
Bayer
Epsilon
Flamsteed
13 CrB
Double Cat
9859
Querying VizieR catalog...
3How easy to spot?
Sign in
and configure your equipment and default location to see a personalized row.
| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | Medium+ | Medium+ | Medium |
| 50 mm finder 50mm finder | Easy | Easy | Easy |
| 150 mm telescope 150mm scope | Easy | Easy | Easy |
Easy
Medium
Hard
Very hard
Impossible
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
4Visibility
Set a location in User Settings to see visibility data.
Best season
Apr – Jun
(peak: May)
5Survey Image
Loading survey image…
Explore
7
Size Comparison
Querying VizieR for stellar data…
8
Compare Stars
9
Spectral Classification
10
Hertzsprung-Russell Diagram
Loading HR 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
15
Exoplanets
1 known planet
View in 3D
View this system in the 3D Orrery
Interactive Keplerian orbits, procedural planet textures, habitable zone.
| Planet | Radius | Mass | Period | Distance |
|---|---|---|---|---|
| eps CrB b | 12.70R⊕ | 6.70M♃ | 1.1yr | 228ly |
Habitable Zone
Size & Mass Comparison
About exoplanets — how we find them and which host stars you can observe
Discover
16Stellar Notes
Component B, 12.6v at 2", CPM.
17
Light Travel Time Machine
18
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.
Explore Nightbase
Related knowledge, tools, and stories — no observation planning required.
Arthur Eddington
1919 eclipse expedition confirming general relativity; first theory of stellar interiors; the Eddington limit
Biography
The Hertzsprung-Russell Diagram — Reading Stars Like a Map
The HR diagram turns the night sky into a physics map: every named star has a spot, every spot tells you mass, age, and fate. A guide for amateur observers.
Article
Corona Borealis
Mythology, bright stars, and deep-sky highlights.
Constellation
