HubbleVariable

Hubble's Variable Nebula

Hubble's variable nebula is named (like the Hubble telescope itself)
after the American astronomer Edwin P. Hubble, who carried out some of
the early studies of this object. It is a fan-shaped cloud of gas and
dust which is illuminated by R Monocerotis (R Mon), the bright star at
the bottom end of the nebula.  Dense condensations of dust near the
star cast shadows out into the nebula, and as they move the
illumination changes, giving rise to the variations first noted by
Hubble. The star itself, lying about 2,500 light-years from Earth,
cannot be seen directly, but only through light scattered off of dust
particles in the surrounding nebula. R Mon is believed to have a mass
of about 10 times that of the Sun, and to have an age of only 300,000
years. There is probably a symmetrical counterpart of the fan-shaped
nebula on the southern side of the star, but it is heavily obscured
from view by dust lying between this lobe and our line of sight.

The Hubble Heritage team made this image from observations of R Mon
acquired by William Sparks (STScI), Sylvia Baggett (STScI) and
collaborators.

Image Credit: NASA/The Hubble Heritage Team (AURA/STScI).