18 Monocerotis — Double Star in Monoceros
Observe
1Physical Properties
Magnitude
4.47
Spectral Type
K0+IIIaBa0.2
Star Color
Orange
(B-V 1.11)
(reddened by dust)
Distance
192 ly
2Position & Identifiers
RA
06h 47m 51.6s
Dec
+02° 24' 44.0"
Constellation
Monoceros
(Mon)
HR
2506
HIP
32578
HD
49293
SAO
114428
Flamsteed
18 Mon
Querying VizieR catalog...
3How easy to split?
Primary
4.5 mag
Companion
11.0 mag
Separation
0.6″
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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
Out of reach for typical amateur telescopes, even at Bortle 3.
4Visibility
Set a location in User Settings to see visibility data.
Best season
Nov – Jan
(peak: Dec)
5Multiple Star System
Separation
0.6″
Companion Mag
11.0
Companion Sp
III
Position Angle
142°
Star Colors
A: Orange
(reddened by dust)
Discoverer
RBR 38
Eyepiece View
80x
Dawes: 1.9″
TFOV: 0.6°
Realistic = true angular size
A: 4.5 · B: 11.0 · Sep: 0.6″ · PA: 142° · N up, E right
Unresolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 2.3″
Explore
7
Size Comparison
Querying VizieR for stellar data…
8
Compare Stars
9
Spectral Classification
10
Hertzsprung-Russell Diagram
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11
Stellar Lifecycle
12
Blackbody Spectrum
13
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
14
Stellar Fusion
Discover
15Stellar Notes
Also classified K0III Ba 0.1.
16
Light Travel Time Machine
17
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.
NGC 2282
Emission nebula — try an OIII filter
Emission Nebula
mag 10.00
1.1°
Monoceros
NGC 2301
Rich open cluster
Open Cluster
mag 6.0
2.2°
Monoceros
Epsilon Mon
Easy double, sep 12.1″
Double Star
mag 4.44
6.4°
Monoceros
Hubble's Variable Nebula
NGC 2261
Reflection nebula around a bright star
Reflection Nebula
mag 10.0
6.7°
Monoceros
15 Mon
Easy double, sep 3.0″
Double Star
mag 4.66
7.7°
Monoceros
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