R Monocerotis

R Monocerotis

File:Ngc2261.jpg R Monocerotis is at the bottom left of this photo. Credit: HST/NASA/JPL
Observation data Epoch J2000      Equinox J2000
Constellation	Monoceros
Right ascension	Template:RA
Declination	Template:DEC
Apparent magnitude (V)	11.85
Characteristics
Spectral type	B8IIIev
Variable type	Herbig Ae/Be star
Astrometry
Distance	2600 ly (800 pc)
Details
Mass	~2–10 Template:Solar mass
Age	~105 yr years
Metallicity [Fe/H]	{{{metal_fe2}}} dex
Other designations
Template:Odlist
Database references
SIMBAD	data

R Monocerotis, abbreviated R Mon, is a very young binary star system in the equatorial constellation of Monoceros. The apparent magnitude of R Mon varies between 10 and 12 and the spectral type is B8IIIe.

File:RMonLightCurve.png

A visual band light curve for R Monocerotis, plotted from ASAS data

This is a massive Herbig Ae/Be star, a type of pre-main-sequence star that is surrounded by an orbiting circumstellar disk of gas and dust. This disk has a mass of Template:Val and extends outward to a distance of under Template:Val from the host. Because of this dust, the star is obscured from direct visual sight but can still be observed in the infrared. R Mon is still in the accretion phase of star formation and it is driving an optically opaque bipolar outflow with a velocity of 9 km/s. The northern flow is blue-shifted, and thus moving more toward the Sun. There is a T Tauri-type stellar companion at an angular separation of Template:Val from the primary.

This system is located in a diffuse nebula called "Hubble's Variable Nebula" (NGC 2261), which is being illuminated by a conical beam of light from the primary.

External links

• Template:APOD