Friday, October 5, 2012


Check out an interview with me on the Star Spot Podcast!  (I apologize in advance for my audio fading in and out.  Maybe I should just speak loudly and excitedly all the time!  Whatever the solution, clearly I need more practice keeping my voice evenly modulated in interviews.)

Wednesday, October 3, 2012

Both Sides Now

PSU grad student Nur Filiz Ak led a project that watched clouds (of a sort) clear out from in between us and some distant black holes... cool to be part of that.

And we just submitted a proposal to look at clouds that have appeared in quasar spectra.  We think the clouds are moving into and out of our line of sight.  If approved, our recent proposal means we'll have looked at the leading and trailing sides of clouds, hence the title of this post...

Tuesday, October 2, 2012

Length of the Seasons, 2011-2012

Fun fact: because Earth's perihelion currently occurs in early January, it is moving faster in its orbit during northern hemisphere fall and winter.  So the northern hemisphere currently gets a week more spring+summer than fall+winter.


Behold the math:

In 2011-2012, length of the northern hemisphere seasons in minutes:

Dec 22 05 30 to Dec 31 24 00 plus
Jan 01 00 00 to Mar 20 05 14: = (9*24+18.5)*60 + ((31+29+19)*24+(5+14/60.))*60

Mar 20 05 14 to Jun 20 23 09: = ((11+30+31+19)*24+(18+46/60.+23+9/60.))*60

Jun 20 23 09 to Sep 22 14 49: = ((10+31+31+21)*24+(0+51/60.+14+49/60.))*60

Sep 22 14 49 to Dec 21 11 12: = ((8+31+30+20)*24+(9+11/60.+11+12/60.))*60

ecl> =128144+129383-134860-133555
ecl> =10888/(24*60.)

sanity check:

Astronomy Activities Manual

Last month saw the publication of my "Astronomy Activities Manual" from Kendall Hunt. If you're looking for in-class activities and a few lab exercises and assignments for students in your undergrad intro astro class, Kendall Hunt has published a wide of activities by numerous authors over the years. You can pick and choose the ones you like and put them together into a custom workbook (and the authors get royalties). I've taken existing activities that I think will work well in my class and added a dozen or so of my own, mostly for the extragalactic half of the course. If you're interested, check out the table of contents below and contact Richard Ludlow at Kendall Hunt (rludlow At to get a sample copy.  (PS - it's not a typo; there is no Lab IV in the book.)