Astronomers have their eyes on a hot group of young stars, watching their every move like the paparazzi.
A new infrared image from NASA’s Spitzer Space Telescope shows the bustling star-making colony of the Orion nebula, situated in the hunter’s sword of the famous constellation.
Like Hollywood starlets, the cosmic orbs don’t always shine their brightest, but vary over time. Spitzer is watching the stellar show, helping scientists learn more about why the stars change, and to what degree planet formation might play a role.
“This is an exploratory project. Nobody has done this before at a wavelength sensitive to the heat from dust circling around so many stars,” said John Stauffer, the principal investigator of the research at NASA’s Spitzer Science Centre, located at the California Institute of Technology in Pasadena.
“We are seeing a lot of variation, which may be a result of clumps or warped structures in the planet-forming [clouds].”
The new image was taken after Spitzer ran out of its coolant in May 2009, beginning its extended “warm” mission. The coolant was needed to chill the instruments, but the two shortest-wavelength infrared channels still work normally at the new, warmer temperature of –243 Celsius.
In this new phase of the mission, Spitzer is able to spend more time on projects that cover a lot of sky and require longer observation times.
One such project is the “Young Stellar Object Variability” programme, in which Spitzer looks repeatedly at the same patch of the Orion nebula, monitoring the same set of about 1,500 variable stars over time. It has already taken about 80 pictures of the region over 40 days. A second set of observations will be made in late 2010.
The region’s twinkling stars are about one million years old. This might invoke thoughts of wrinkle cream to a movie star, but in the cosmos, it is quite young. Our middle-aged Sun is 4.6 billion years old.
The hottest stars in the region, called the Trapezium cluster, are bright spots at centre right in the image. Radiation and winds from those stars has sculpted and blown away surrounding dust. The densest parts of the cloud appear dark at centre left.
Adapted from information issued by NASA / JPL-Caltech.