Observe
1Physical Properties
Magnitude
5.92
Range
5.71 - 6.24
Period
3.2 days
Variable Type
Eclipsing Binary (Algol-type)
Spectral Type
B2V+B3V
Star Color
Blue
(B-V -0.08)
3How easy to follow?
Magnitude
5.7 – 6.2 mag
Amplitude
0.5 mag
Period
3.17 d
Type
EA+SPB
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| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | V. hard+ | V. hard | V. hard |
| 50 mm finder 50mm finder | Medium | Hard+ | Hard+ |
| 150 mm telescope 150mm scope | Medium | Medium | Medium |
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
May – Jul
(peak: Jun)
5Survey Image
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6Light Curve
7Comparison Stars for V539 Ara (5.7–6.2)
Nearby stable stars for estimating brightness (AAVSO)
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Explore
8
Size Comparison
Querying VizieR for stellar data…
9
Compare Stars
10
Spectral Classification
11
Hertzsprung-Russell Diagram
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12
Stellar Lifecycle
13
Blackbody Spectrum
14
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
15
Stellar Fusion
Discover
16Stellar Notes
EA 5.66 - 6.18V, 3.169128d.
3.170d, K 154k/s, V0 -6k/s, msin3i 6.67, asini 6.71. Equal components. vsini secondary 119k/s.
Sometimes called Upsilon1 Ara, more often Nu1; generally no letter.
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
Variable Stars — A Guide for Observers
A practical guide to visual observation of variable stars: estimating magnitudes, finding comparison stars, recording data, and contributing to science with AAVSO.
Article
Ara
Mythology, bright stars, and deep-sky highlights.
Constellation
