Monthly Archives: February 2012

Solar System Graphs



Buying a star

Last week, I brought the portable planetarium that I run (the Fisk-Vanderbilt NASA Astronomy Roadshow) to a school north of Nashville.  From both the parents and the students, I got questions about buying a star for someone.  I get these questions a lot – from people when I do outreach, from friends for whom I’m “their” astrophysicist, from students…  It is a really nice idea and very sweet, but IT IS NOT WORTH IT.  Should you do buy a star for someone, you are giving your money away to some opportunists.  The star name company will give you a nice certificate, put your name in a database, and take $50 (or more).  However, there are several companies out there, each with their own databases, and they don’t talk to each other.  “Your” star could also be several other people’s star.  Also, the naming is in no way official – no astronomer will ever, EVER call your star by the name you “buy” – astronomers have our own, internationally agreed upon, usually boring numeric names/designations.

More importantly, the sky is free :)  We should keep it that way.

If you would like more information

For my class…

If you’re in my Solar System class, please put a comment here showing that you’ve found my blog and that you’re following it.  Just post your FIRST name (and your last name initial if you’re Ian or David ;) ).

Planet Retraction??

In the world of exoplanets (and all of science really), one has to be very careful and very sure of what one is publishing.  Researchers were very sure and very excited when they discovered what looked like a planet around the star Fomalhaut.  Totally looked like an open-and-shut case: they took a picture of Fomalhaut with the Hubble Space Telescope in 2004 and then again in 2006 and saw that there was a spot that moved!  This gave us the infamous “Eye of Sauron” picture :)

Fomalhaut and and the "exoplanet" Fomalhaut-b - "Eye of Sauron" picture

Astronomers love this exoplanet because it is one of the VERY FEW (like 7) planets we actually have images of.  All of the other ones are found through somewhat indirect means – transiting and star wobble (we’ll extensively discuss in class).   But for Fomalhaut-b, all subsequent images have been unable to find the spot again :(  Finally, it seems the infrared Spitzer Space Telescope has nailed the coffin shut…  It took a picture and the exoplanet is not there.  The exoplanet SHOULD be very bright in the infrared because it is hot.  But it is not there.

Bad Astronomer Phil Plait gives a great overview of the topic here and at the bottom of the post has a FANTASTIC little slideshow gallery detailing the planets we ACTUALLY have images of (all 7 of them).

These things happen – new information comes along and we have to re-think all stuff before it.  I’ll be interested to see how Wikipedia gets updated with the new information :)  The entries for Fomalhaut, Fomalhaut-b, and exoplanets will all need to modified at least :)

Global Warming Issues :)

It’s unfortunate that these days, “global warming” is such a dirty word; tis a fascinating topic and one we’ll be investigating a bit during our course (in Unit 3 when we talk about the rocky planets).  Despite the fact we’ll be looking at this more later, I HAVE to post about two things that I found yesterday that remind me of global warming issues.

1.  A Bad Astronomy blog post about new research about the cause of the Little Ice Age also linked to some new data put out by NASA stating the Sun cannot be the cause of global warming. This claim that the Sun’s natural increase in temperature over time (increase is true) is the cause of what we are calling “global warming” is one of the big drums that climate change deniers keep beating on.  But it’s simply not true.  We just go to the data (like the folks at NASA did in the above article).  We’ll talk about it more in class.

2.  One of my sisters is a landscape designer and she provided a link to the newly updated “Plant Hardiness” map published by the USDA.  It shows that the hardiness zones (basically what kinds of plants you can put outdoors) are shifting northerly a bit.


However, they are careful to put this statement on their website:

“Climate changes are usually based on trends in overall average temperatures recorded over 50-100 years. Because the USDA PHZM represents 30-year averages of what are essentially extreme weather events (the coldest temperature of the year), changes in zones are not reliable evidence of whether there has been global warming.”

There are other factors in the shift, like better data (more coverage, more accurate) available now, but regardless, it seems mighty interesting to me :)