A bubble in the WIYNe

When  you want to study something really big in the sky, it helps to have a wide field of view. The Full Moon occupies about 1/2 of a degree in the nighttime sky, and that’s quite a nice chunk. But the folks over at the National Optical Astronomy Observatory (NOAO) are hoping to go wider with the new One Degree Imager (ODI) currently under development. As part of its commissioning, the camera was mounted to the 3.5-meter WIYN telescope and made this:

NGC 7635: The Bubble Nebula captured by the new ODI camera on WIYN. Image Credit: T.A. Rector (University of Alaska Anchorage), WIYN ODI team & WIYN / NOAO / AURA / NSF. More image sizes can be found here.

Talk about a bubble floating in the WIYNe (see what I did there? I’ll be here all week!)! This is NGC 7635, also known as the Bubble Nebula, a star forming region about 7,800 light-years away in the constellation Cassiopeia. The nebula itself is about 10 light-years across. At its center is a great bubble which is being blown by fast stellar winds coming from the bright star toward the top of the bubble. This star, known as BD+602522, is a relatively young giant star believed to be somewhere between 10 and 20 times the mass of our own Sun.

And it’s a hot star too – at 34,320K it’s more than six times hotter than our Sun*, gusting out winds of over 2,000 kilometers per second – that’s 4 million miles per hour (or 7 million kilometers per hour)! That wind is responsible for “inflating” the bubble, which itself is 2-4 light years across.

But take another look at the star and you’ll notice that it’s off center from the bubble. That’s because the “surface” of the bubble is slamming into cooler, denser gas in the walls of the nebula. But the density of the gas and dust in the nebula isn’t uniform so the outflow slams into cooler gas toward the top of the image and heats up, causing the gas to glow. Meanwhile, outflow from the star is free to pass through less-dense gas toward the bottom. The result is a squashed bubble with one edge closer to the star than the other.

The ODI is still under development. As its name implies, it is designed to take a full one-degree by one-degree high resolution image of the sky. The full image of NGC 7635 covers 25 by 25 arc minutes, just a little smaller than the full moon. But when completed, ODI is going to be one heck of a sky-grabbing machine.

According to Moore, et al (2002), it’s actually a bit cooler than expected for a star this massive.

Sugar found around a star. Sweet!

Rho Ophiuchi star-forming region in infrared, imaged by NASAs WISE spacecraft. The little red dot in the box is IRAS 16293-2422, a young binary star with a mass similar to our Sun. An artist’s impression of glycolaldehyde (C2H4O2) is shown in the disk surrounding the star.

As stars form, a swirling disc of material surrounds the young star. These dics are mostly composed of simple molecular compounds such as molecular hydrogen (H2) and carbon monoxide (CO) but there’s also some relatively complex stuff there too, including sugar!

Ok, it’s not exactly the same kind of sugar that we add to our coffee, but it’s really not that much different, either. It’s glycolaldehyde (C2H4O2) which is a fairly simple form of sugar. Sweet!

The sugar was detected by Jes Jørgensen and his team using the Atacama Large Millimeter/submillimeter Array (ALMA)  in the disc surrounding a young Sun-like star called IRAS 16293-242. The  molecular compounds in this disc are cold so they therefore they emit radiation at long wavelengths – longer than infrared, but shorter than radio. It’s here that you can start to detect complex molecules and sure enough, Jørgensen and his team found a lovin’ spoonful of glycolaldehyde!

Why is this so deliciously awesome? It turns out that glycolaldehyde is one of the ingredients found in RNA. You might remember from high school biology that RNA is similar to DNA except for the type of sugars present. (There are some other differences between RNA and DNA as well, which are worth reading up on.)

So there you have it – discs surrounding stars can have the building blocks of life in them, and it’s in these discs where planets form. It seems that the building blocks of life are fairly common and seed the formation of new planets. Sweet!