Delta Circini — Star in Circinus
Observe
1Physical Properties
Magnitude
5.09
Range
5.04 - 5.20
Period
3.9 days
Variable Type
Eclipsing Binary (Algol-type)
Spectral Type
O8.5V
Star Color
Blue
(B-V -0.06)
2Position & Identifiers
RA
15h 16m 56.7s
Dec
-60° 57' 27.0"
Constellation
Circinus
(Cir)
HR
5664
HIP
74778
HD
135240
SAO
253084
Bayer
Delta
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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
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Best season
Apr – Jun
(peak: May)
5Survey Image
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6
Size Comparison
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7
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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
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14Stellar Notes
Component A of double, Ell?, amp. 0.08V.
CPM with the triple star HR 5661. Faint companion of HR 5664, G5V, probably optical.
3.9025d, K 158.3k/s, V0 +9.2k/s, asini 8.46.
Also classified O7.5III((f)).
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.
AX Cir
Pulsating variable, period 5.3d
Variable Star
mag 5.87
4.0°
Circinus
Rigil Kentaurus
HIP 71681; Alpha2 Centauri
Easy double, sep 8.1″
Double Star
mag 1.33
4.5°
Centaurus
NGC 5715
Open cluster
Open Cluster
mag 10.0
5.4°
Circinus
NGC 5938
Barred spiral galaxy
Galaxy
mag 11.49
6.3°
Triangulum Australe
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Article
Circinus
Mythology, bright stars, and deep-sky highlights.
Constellation
