V640 Mon
HIP 31646
DoubleStar
Mon
Visible
Level 5
Expert level - Requires steady seeing
Physical Properties
Magnitude
6.06
Spectral Type
O8p
Star Color
White
(B-V 0.05)
Position & Identifiers
RA
06h 37m 24.1s
Dec
+06° 08' 07.0"
Constellation
Mon
HR
2422
HIP
31646
Variable ID
V640 Mon
Querying VizieR catalog...
Visibility
Set a location in User Settings to see visibility data.
Multiple Star System
Separation
1.2″
Companion Mag
11.0
Companion Sp
O8.5
Position Angle
251°
Star Colors
A: White
B: Blue
Discoverer
TRN 22
Eyepiece View
80x
Dawes: 1.9″
TFOV: 0.6°
Realistic = true angular size
Sep: 1.2″ · PA: 251° · N up, E left
Unresolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 3.1″
Size Comparison
Querying VizieR for stellar data…
Stellar Lifecycle
Spectral Classification
Hertzsprung-Russell Diagram
Loading HR diagram…
Blackbody Spectrum
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
Stellar Notes
6.04 - 6.08V, irregular variations, possibly transition from O- to WR-type spectrum. Polarization variable.
14.3961d, K 205.2k/s, V0 +24.9k/s, asini 40.6. Masses each about 55 solar. The secondary is underluminous for its | mass and may be smaller than the primary. vsini secondary 130:k/s.
Mon OB2; in HII reg.; a SN remnant, D14. Near NGC 2264 in region of expanding OB assoc. in gas and dust. See note for HR | 2456. Embedded in 21-cm emission.
Shell star. Also classified O8f and O7.5III(f), O8V + O8f.
Plaskett's star.
Survey Image
Loading survey image…