NASA has released a new image of the Orion nebula using the Spitzer space telescope. They are taking a look at the same patch of sky while they watch about 1,500 variable stars. These stars are relatively young in age, only about 1 million years old. Since they are so young, their brightness levels vary, thus making them variable stars. From the accompanying article:
The hottest stars in the region, called the Trapezium cluster, are bright spots at center right. Radiation and winds from those stars has sculpted and blown away surrounding dust. The densest parts of the cloud appear dark at center left.
This image was taken after Spitzer’s liquid coolant ran dry in May 2009, marking the beginning of its “warm” mission. Light from the telescope’s remaining infrared channels has been color-coded: 3.6-micron light is blue and 4.5-micron light is orange.
