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Constellations / Monoceros

Monoceros

Monocerotis

Equatorial 482 sq° Mon

Brightest star: Beta Monocerotis

Mythology

The Unicorn, a relatively modern constellation. Beta Monocerotis is one of the finest triple star systems in the sky.

Observing Highlights

Lies in a rich Milky Way field between Orion and Canis Major. Contains the Rosette Nebula (NGC 2237), Christmas Tree Cluster (NGC 2264), and Hubble's Variable Nebula (NGC 2261).

Main Stars

20

HIP 37447; Alpha Mon; 26 Mon

3.93 mag K0 III

HIP 29651; Gamma Mon; 5 Mon

3.98 mag 54.4″ B: 13.1 K1.5IIIBa0.3

HIP 34769; Delta Mon; 22 Mon

4.15 mag 32.9″ B: 13.0 A2V

HIP 39863; Zeta Mon; 29 Mon

4.34 mag 33.2″ B: 10.3 G2Ib

HIP 30419; Epsilon Mon; 8 Mon

4.44 mag 12.1″ B: 6.6 A5IV

HIP 32578; 18 Mon

4.47 mag 0.6″ B: 11.0 K0+IIIaBa0.2

HIP 31216; 13 Mon

4.50 mag A0Ib

Beta Mon

HIP 30867; Beta Mon; 11 Mon

4.60 mag 7.3″ B: 5.0 B3Ve

HIP 31978; 15 Mon

4.66 mag 3.0″ B: 7.8 O7V((f))

HIP 39211; 28 Mon

4.68 mag K4III

HIP 32533; 17 Mon

4.77 mag K4III

HIP 34622; 20 Mon

4.92 mag 67.8″ B: 12.9 K0III

HIP 39079; 27 Mon

4.93 mag K2III

HIP 28574; 3 Mon

4.95 mag 2.0″ B: 8.0 B5III

HIP 33971; 19 Mon

4.99 mag B1V

HIP 28325; 2 Mon

5.03 mag A6IIIm vs
5.05 mag B2V

HIP 30772; 10 Mon

5.06 mag 77.0″ B: 9.6 B2V
5.07 mag M1+Ib-IIa
5.10 mag B5Vn

Double Stars

15

Beta Mon

HIP 30867; Beta Mon; 11 Mon

4.60 mag 7.3″ B: 5.0 B3Ve
6.72 mag 12.1″ B: 6.6 F5V

HIP 30419; Epsilon Mon; 8 Mon

4.44 mag 12.1″ B: 6.6 A5IV
5.90 mag 23.9″ B: 8.7 F5V
6.23 mag 30.6″ B: 7.8 B9V
6.14 mag 16.2″ B: 9.1 B2V:nne
6.27 mag 20.8″ B: 9.2 A0Vn
6.17 mag 24.6″ B: 10.1 G5II

HIP 34234

6.49 mag 6.4″ B: 10.1 B0.5V+F5III

HIP 29651; Gamma Mon; 5 Mon

3.98 mag 54.4″ B: 13.1 K1.5IIIBa0.3

HIP 31385; 14 Mon

6.45 mag 11.0″ B: 10.6 A0V s
6.16 mag 19.4″ B: 10.4 gM1
5.77 mag 6.6″ B: 11.1 F2V

HIP 31978; 15 Mon

4.66 mag 3.0″ B: 7.8 O7V((f))
5.99 mag 4.3″ B: 10.0 A5IV s

Variable Stars

3

HIP 30541

5.98 mag 5.6 - 6.6 DCEP F7Iab-K1Iab

HIP 28321; 1 Mon

6.12 mag 5.94 - 6.31 HADS F2IV

HIP 32838

6.29 mag A2pSrCrEu

Deep Sky Objects

30
Open Cluster (24)

NGC 2244

4.8 mag 24

NGC 2323

5.9 mag 16.
3.9 mag 30.
7.5 mag 15.
7.1 mag 20.

NGC 2506

7.6 mag 7
6.0 mag 12.
7.3 mag 10.
8.0 mag 20.
7.2 mag 12.
6.7 mag 7.
8.4 mag 11.
8.5 mag 7.
8.4 mag 8.

Rosette nebula

NGC 2239

— mag 16.
9.0 mag 8.
8.9 mag 3.
11.0 mag 5.
10.0 mag 7.
9.7 mag 4.
10.0 mag 4.
11.0 mag 3.
12.0 mag 5.
11.0 mag 4.
Galaxy (1)
15.0 mag 1.8 Sc
Planetary Nebula (1)
— mag 0.9
Emission Nebula (2)

NGC 2237

C49

6.0 mag 80
— mag 15.
Diffuse Nebula (1)
— mag 25.
Reflection Nebula (1)
10.0 mag 2