The AstroStat Slog

Our hometown rag (the Boston Globe) runs an occasional series of photo collections that highlight news stories called The Big Picture. This week, they take a look at the Sun: http://www.boston.com/bigpicture/2008/10/the_sun.html

The pictures come from space and ground observatories, from SoHO, TRACE, Hinode, STEREO, etc. Goes without saying, the images are stunning, and some are even animated. The real kicker is that images such as these are being acquired by the hundreds, every hour upon the hour, 24/7/365.25 . It is like sipping from a firehose. Nobody can sit there and look at them all, so who knows what we are missing out on. Can statistics help? Can we automate a statistically robust “interestingness” criterion to filter the data stream that humans can then follow up on?

People of experience would say very differently and wisely against what I’m going to discuss now. This post only combines two small cross sections of each branch of two trees, astronomy and statistics. Continue reading ‘survey and design of experiments’ »

The CfA is celebrating the 100th anniversary of the discovery of the Cepheid period-luminosity relation on Nov 6, 2008. See http://www.cfa.harvard.edu/events/2008/leavitt/ for details.

[Update 10/03] For a nice introduction to the story of Henrietta Swan Leavitt, listen to this Perimeter Institute talk by George Johnson: http://pirsa.org/06050003/

To my personal thoughts, the history of astronomy is more interesting than the history of statistics. This may change tomorrow. Harvard statistics department (chair Xiao-Li Meng) organizes a symposium titled

Quintessential Contributions:
Celebrating Major Birthdays of Statistical Ideas and Their Inventors
When: Saturday, September 27, 2008, 9:45 AM - 5:00 PM
Where: Radcliffe Gymnasium, 18 Mason Street, Cambridge, MA

Continue reading ‘Quintessential Contributions’ »

Astronomers tend to think in Bayesian way, but their Bayesian implementation is very limited. OpenBUGS, WinBUGS, GeoBUGS (BUGS for geostatistics; for example, modeling spatial distribution), R2WinBUGS (R BUGS wrapper) or PyBUGS (Python BUGS wrapper) could boost their Bayesian eagerness. Oh, by the way, BUGS stands for Bayesian inference Using Gibbs Sampling. Continue reading ‘BUGS’ »

10:00am local time, Sept. 10th, 2008
As the first light from Fermi or GLAST, LHC First Beam is also a big moment for particle physicists. Find more from http://lhc-first-beam.web.cern.ch/lhc-first-beam/Welcome.html. Continue reading ‘LHC First Beam’ »

UChicago, my alma mater, is doing alright for itself in the spacecraft naming business.

First there was Edwin Hubble (S.B. 1910, Ph.D. 1917).
Then came Arthur Compton (the “MetLab”).
Followed by Subramanya Chandrasekhar (Morton D. Hull Distinguished Service Professor of Theoretical Astrophysics).

And now, Enrico Fermi.

A GLAST-related opportunity: A Summer Science Institute at SLAC on Cosmic Accelerators is scheduled for August 4-15 in anticipation of GLAST science, and the co-directors welcome participation by students, postdocs, and researchers (even those with no background in astrophysics). The registration deadline is July 31. Continue reading ‘SLAC Summer Institute’ »

A conference that I wanted to go but never made, started today. With relief, they have presentation files from the previous workshop
http://www.stanford.edu/group/mmds and I expect the same for this year. The workshop title may not attract astronomers but the contents, tools, methodologies, and theory are modern astronomy friendly. Astronomers can motivate, initiate, and push further these researchers at the workshop, which I believe currently happening without broad recognitions (foremost interdisciplinary works tend to stay within research groups).

You all may have heard that GLAST launched on June 11, and the mission is going smoothly. Via Josh Grindlay comes news that Steve Ritz, the GLAST Project Scientist at GSFC, is keeping a weblog dedicated to it at

http://blogs.nasa.gov/cm/blog/GLAST

and intends to post status reports and related information on it.

Earlier this year, Peter Edmonds showed me a press release that the Chandra folks were, at the time, considering putting out describing the possible identification of a Type Ia Supernova progenitor. What appeared to be an accreting white dwarf binary system could be discerned in 4-year old observations, coincident with the location of a supernova that went off in November 2007 (SN2007on). An amazing discovery, but there is a hitch.

And it is a statistical hitch, and involves two otherwise highly reliable and oft used methods giving contradictory answers at nearly the same significance level! Does this mean that the chances are actually 50-50? Really, we need a bona fide statistician to take a look and point out the errors of our ways.. Continue reading ‘Did they, or didn’t they?’ »

There is a new report from Bernabei et al. (arXiv:0804.2741) of the direct detection of the effects of Dark Matter that is causing a lot of buzz. (The Bad Astronomer has a good summary.) They find yearly modulation in their detected scintillation rate that matches what you would expect if the Earth were rushing through Galactic Dark Matter as it goes around the Sun. They have worked out the significance of the modulation to be 8.2 sigma. Significant! But significant of what? Continue reading ‘Is 8-sigma significant enough for you?’ »

AstroGrid Desktop Suite is available. Check the AstroGrid website http://www.astrogrid.org for more informations. Continue reading ‘AstroGrid Desktop Suite’ »

From Prajval Shastri of IIAp comes news of the sequel to last year’s Astrostatistics school at Kavalur, India:

The Indian Institute of Astrophysics and the Center for Astrostatistics, Pennsylvania State University (USA) are jointly organising an 8-day school in fundamental statistical inference as applicable to astrophysical problems during 9-16 July, 2008 (www.iiap.res.in/astrostat). The school is intended for practising astrophysics researchers at all levels. Details may be found on the website of the school.

Continue reading ‘AstroStatistics School in India’ »

Bradley Efron, Stanford University
11:00 AM, Friday, April 4, 2008
Sever Hall Rm. 103
Title: SIMULTANEOUS INFERENCE: WHEN SHOULD HYPOTHESIS TESTING PROBLEMS BE COMBINED
Its abstract and other informations at http://www.stat.harvard.edu/Colloquia_Content/Efron08.pdf
Continue reading ‘Prof. Brad Efron visits Harvard’ »