Astronomer H-R diagram

Most people who've done an astronomy course will have heard of the Hertzsprung-Russell diagram. It was developed to show the relationships between the temperature (or colour) of a star and its luminosity. The other week I saw a tweet referring to someone as an "astronomy media star". This interesting stellar classification got me thinking about an alternative version of the H-R diagram. In my alternate reality I imagined a version classifying astronomers* and so, after a little consultation with other astronomers (thanks Sarah, Tess, Mike, Paul and Amanda) and some free time**, I present...

Click to embiggen. Apologies to Hertzsprung and Russell. If you are one of the names on this plot and you feel your numbers are very wrong, let me know and I'll update it. CREDIT: Stuart
This isn't in any way supposed to be accurate - it is qualitative - and most of the "Main Career Sequence" is invented based on expectations of an evolutionary sequence assuming little use of the internet before becoming an astronomer. Mega-stars such as Dr Brian May may follow a totally different path. Of course, not all astronomers make it along the main sequence and many go off to other jobs through either an "academia runaway" or a "funding instability crisis". The "dark astronomers" (we have dark matter and dark energy so why not?) are theorised to exist but haven't been directly detected so if you have evidence for one, please let me know.

For those wanting technical details, the data for the red stars comes from NASA's ADS/SPIRES-HEP (limited to peer review) and searching for the person's name (in quotation marks) on Google. Both numbers are affected by name-sake contamination and the Google-dance/search customisation adds to the uncertainty on the y-axis. Update 2010-07-22T11:10:00 UT: It turns out that Google gives wildly different results depending on which Google you are connected to. Being in the UK I was automatically redirected to and that is where these numbers come from. seems to produce more search results. I may re-make this plot using as the standard.

If anyone has the time to properly classify a few hundred astronomers you are welcome to do that and send me the data!

* I know Brian Cox is technically a particle physicist but he is the Sun Professor which makes him almost a solar physicist ;-)
** Internet-based diversions such as this usually result in people saying "he has too much free time". That is not entirely inaccurate.

Posted in astro blog by Stuart on Wednesday 21st Jul 2010 (12:36 BST) | Permalink

Planck All-sky

This morning, the European Space Agency and the Planck Consortium released the Planck satellite's first view of the entire sky. Behold.

Planck sky
A false-colour image of the whole sky as seen by Planck. The dust throughout the Galaxy is shown in blue. In the background, the mottled yellow features are relic radiation, called the Cosmic Microwave Background, which contains information about the earliest stages of the Universe. This image is a low-resolution version of the full data set. CREDIT: ESA, Planck LFI and HFI Consortia (2010)
Planck was launched on May 14th 2009 and, after three months of travelling and instrument testing, started taking science data in August last year. Early on we were treated to first light images, an image of cold dust around the Galactic Centre, and patches of the sky near Orion and Perseus. Now, for the first time, we get to see a view of the entire sky as seen by Planck.

Planck's main task is to study the echoes of the Big Bang; the cosmic microwave background (CMB) radiation. It builds on the successes of COBE and WMAP that have gone before but covers a much bigger range of frequencies (30-857 GHz) and will ultimately be more sensitive. The range of frequencies is very important as it helps to disentangle the many sources of microwave radiation in the Universe that detract from the cosmological signal that Planck is trying to observe.

Today's image may vaguely resemble the Flying Spaghetti Monster* but actually shows our galaxy - the Milky Way - across the middle and you can see streamers of cold gas and dust in our local neighbourhood (local means within a few hundred light years) stretching above and below it. To get your bearings, there is an annotated version and you can also explore it in Chromoscope! Near the top and bottom of the image you'll see a mottled pattern. That is a glimpse of the CMB; the remains of the fireball out of which our Universe sprang into existence 13.7 billion years ago.

This image is only the start of the amazing data that is to come from Planck. Planck is imaging the entire sky every 8 months or so and that means it produces lots of data. There is plenty of work ahead, and at least two full surveys of the sky are required to fully calibrate everything, so the first cosmological science isn't expected until 2012. In a couple of years, we should expect to see a much better and higher resolution view of the Universe. Meanwhile, my congratulations to all the people that have worked on Planck over the past 20 years. The hard work was certainly worth it.

* It doesn't help that the filename contains "FSM" (which actually stands for "full-sky map").

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Posted in astro blog by Stuart on Monday 05th Jul 2010 (09:05 BST) | Permalink
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