Asellus Borealis — Star in Cancer
HIP 42806; Gamma Cancri; 43 Cancri
Observe
1Physical Properties
Magnitude
4.66
Spectral Type
A1IV
subgiant
Star Color
White
(B-V 0.02)
Distance
204 ly
2Position & Identifiers
RA
08h 43m 17.1s
Dec
+21° 28' 07.0"
Constellation
Cancer
(Cnc)
HR
3449
HIP
42806
HD
74198
SAO
80378
Bayer
Gamma
Flamsteed
43 Cnc
Querying VizieR catalog...
3How easy to spot?
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| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | Medium+ | Medium | Hard+ |
| 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
Dec – Feb
(peak: Jan)
5Survey Image
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Explore
6
Size Comparison
Querying VizieR for stellar data…
7
Compare Stars
8
Spectral Classification
9
Hertzsprung-Russell Diagram
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10
Stellar Lifecycle
11
Blackbody Spectrum
12
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
13
Stellar Fusion
Discover
14Stellar Notes
Component A suspected occultation double. Three visual companions.
Hyades group.
Asellus Borealis.
15
Light Travel Time Machine
16
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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Mythology, bright stars, and deep-sky highlights.
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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.
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