Polaris Australis — Star in Octans
HIP 104382; Sigma Octantis
Observe
1Physical Properties
Magnitude
5.47
Range
5.42 - 5.48
Period
2.3 hours
Variable Type
Delta Scuti (Pulsating)
Spectral Type
F0III
giant
Star Color
Yellow-white
(B-V 0.27)
Distance
323 ly
2Position & Identifiers
RA
21h 08m 46.2s
Dec
-88° 57' 23.0"
Constellation
Octans
(Oct)
HR
7228
HIP
104382
HD
177482
SAO
258857
Bayer
Sigma
Variable ID
Sig Oct
Querying VizieR catalog...
3How easy to spot?
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| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | Medium | Hard+ | 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
Jul – Sep
(peak: Aug)
5Survey Image
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Explore
6
Size Comparison
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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
Delta Sct, amp. 0.05V, 0.04B, 0.097d.
Polaris Australis (so called by Wollaston in 1789).
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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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
Octans
Mythology, bright stars, and deep-sky highlights.
Constellation
