HR 4729 — Double Star in Crux
Observe
1Physical Properties
Magnitude
4.86
Spectral Type
B4IV
subgiant
Star Color
Blue-white
(B-V -0.12)
2Position & Identifiers
3How easy to split?
Primary
4.9 mag
Companion
10.5 mag
Separation
2.4″
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| Telescope | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| 80 mm refractor 80mm refr. | V. hard | V. hard | V. hard |
| 150 mm Newton 150mm Newt. | V. hard+ | V. hard+ | V. hard+ |
| Celestron C8 (203 mm SCT) C8 203mm | V. hard+ | V. hard+ | V. hard+ |
Easy
Medium
Hard
Very hard
Impossible
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
To reach "Medium" at Bortle 3, you'd need at least a 410 mm reflector.
4Visibility
Set a location in User Settings to see visibility data.
Best season
Feb – Apr
(peak: Mar)
5Multiple Star System Triple B: optical
Components
3 (triple)
Component IDs
AB
Separation
2.4″
Companion Mag
10.5
Position Angle
53°
Star Colors
A: Blue-white
Discoverer
TOK 7
Component C of triple system with HR 4730-4731, at 90" CPM.
Eyepiece View
80x
Dawes: 1.9″
TFOV: 0.6°
Realistic = true angular size
A: 4.9 · B: 10.5 · Sep: 2.4″ · PA: 53° · N up, E right
Resolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 2.3″
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6
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7
Spectral Classification
8
Hertzsprung-Russell Diagram
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9
Stellar Lifecycle
10
Blackbody Spectrum
11
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
12
Stellar Fusion
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13Stellar Notes
1.225155d, K 43.1k/s, V0 +8.4k/s, asini 0.726.
Sco-Cen assoc.
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.
Acrux
HIP 60718; Alpha1 Crucis
Easy double, sep 3.5″
Double Star
mag 1.33
0.0°
Crux
Alpha Cru
HIP 60718; Alpha2 Crucis
Hot blue O-type star
Star
mag 1.73
0.0°
Crux
NGC 4349
Open cluster
Open Cluster
mag 7.4
1.3°
Crux
Coalsack Nebula
Dark nebula — shows as a void against the Milky Way
Dark Nebula
mag 12.0
2.4°
Crux
Epsilon Mus
Semi-regular variable, range 4.0–4.3
Variable Star
mag 4.11
4.9°
Musca
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