Blogs

As part of the annual meeting of the American Astronomical Society, NASA released today the most detailed ever infrared image of the Cygnus X region.

The mysterious Cygnus X region is the closest major star formation region to our solar system. It dwarfs the more local star formation regions in the Gould Belt such as Sco OB2 and the Orion molecular clouds. At visual frequencies Cygnus X is obscured by the Rift dust clouds. It was originally detected at radio frequencies and now a team led by Harvard astronomer Joseph Hora has revealed its full glory using infrared images from the Spitzer space telescope.

Hora tells me that astronomer-illustrator Robert Hurt helped to create the image. It is based on data collected before Spitzer ran out of coolant and combines four infrared frequencies.

Up to this point, the most detailed Cygnus X image available was this one from MSX (the Spitzer image is rotated roughly 90 degrees to the MSX image). I'll add the new Spitzer image to the Milky Way Explorer in the near future.

I blogged about the distance to Cygnus X in November 2010 and noted that there was a controversy about whether the objects in this direction are really part of a single region. A recent paper uses radio parallax measurements to establish that there is indeed a single major star formation region in this direction and like our own Gould Belt, it is part of the Orion spur.

The infrared image is centered upon the compact starburst cluster and OB association Cyg OB2, which has created a huge bubble in the interstellar medium. The radio parallax study shows that many other objects in this direction and at a similar distance have motions different from the expanding bubble surrounding Cyg OB2 and so probably developed independently from Cyg OB2 within the same gigantic molecular cloud.

Hundreds of new visitors have arrived at Galaxy Map over the past few days looking for a map showing the location of the newly discovered Earth-like planet Kepler-22b and its G5V class parent star Kepler-22. I've never seen this kind of response to a news story before - usually traffic spikes are caused by other sites like Astronomy Picture of the Day linking to Galaxy Map. In this case the traffic spike has come from hundreds of people independently searching for a map.

To meet the demand, I've created a poster derived from several Galaxy Map resources.

The poster is here:

http://galaxymap.org/kepler22b/poster.png

The poster is based on these resources:

Interactive map of the Gould Belt region:

http://galaxymap.org/detail_maps/gould.html

Basic plan of the Milky Way:

http://galaxymap.org/drupal/node/171

Milky Way Explorer:

http://galaxymap.org/drupal/node/127

On the Gould Belt region map, red balls are HII regions of ionised molecular hydrogen gas, green balls are dusty molecular clouds, orange circles are star clusters and the small dots are extremely bright stars (typically supergiants or O and B class hot stars).

Below is an image of Sh 2-284 I made this morning from the WISE data. The speed of the image server is now reasonably fast - I think the problem yesterday was just that it was down for a while.

I used all four channels, using the equations:

red = w4
green = 0.25*w2+0.75*w3
blue = 0.25*w2+0.75*w1

with a bit of preprocessing of the individual channel FITS files using Aladin first.

I've rotated the image to the right by 90° to compare it with an earlier image I made using Spitzer IRAC and SuperCOSMOS data.

Here's the WISE image:

(A much larger 4095x4095 version can be downloaded by clicking here.)

and here's the earlier Spitzer/SuperCOSMOS image for comparison:

The two obvious differences are that:

• the Spitzer data is higher resolution
• the WISE data reveals more at longer (redder) wavelengths than Spitzer's IRAC instrument. (Spitzer's separate MIPS instrument also covers the longer wavelengths). For this reason the WISE image shows more structure in the interior of Sh 2-284 than IRAC.

It looks like the WISE image server is going to be very useful and I'm looking forward to making more images!

The first block of WISE infrared data was released a couple of days ago and there is an explanation of how to access the images here. Unfortunately all that is provided is an (when I tried it) unbearably slow postage stamp image server.

There is nothing like the full pannable and zoomable maps available for other infrared missions such as IRAS or Spitzer GLIMPSE/MIPSGAL. This is a real shame as the WISE all sky data is crying out for a Google Sky like interface.

The first block of data is mostly confined to the inner galaxy with a few key bits of the Gould Belt (Orion/Ophiuchus) and the outer galaxy provided as well. You can see the release map here.

I understand that the lack of a more elaborate interface is partially a funding issue. I hope that some resources become available (Google or Microsoft are you listening?) by the time the full data is released next year.

In the mean time (and if the postage stamp server becomes more responsive) I hope to start doing the Gum/RCW/Sharpless catalog images in infrared.

Visitors to this site sometimes ask me about the nearest stars to our Sun. Even the dimmest star shown on the maps on this site is 1400 times brighter than the Sun and most are quite far away.

I've occasionally thought of creating a near star map for fun, but now I see that the RECONS project have done the job for me with this map showing every known star within 10 parsecs:

http://www.chara.gsu.edu/~riedel/10pc2011.html

All that is needed is an overlay to identify each individual star. Hopefully at some point they will add something like that. (I can't because RECONS has released less than half their star data so far.)

There is a much bigger 25 parsecs map (warning slow to load) here:

http://www.chara.gsu.edu/~riedel/25pc2011.html