Steinn Sigurðsson
Professor of Astrophysics at Pennsylvania State University. Science Editor at Astrophysical Journal. Icelandic. Herder of Cats.
catdynamics
Posts by this author
March 2, 2009
monday, again, already?
we get more fresh blood, and contemplate new topics
some interesting preprints out there on astro-ph:
the Bologna group has hi-res spectroscopy of old LMC clusters, and they see the dreaded Na-O anticorrelation there also! ref
Aargh, there is no escape...
the Sweigart and…
February 27, 2009
Ed continues, and does case A, B and C mass transfer.
Conservatively, mostly.
From an NWU crowd talk at CfA
For conservative mass transfer, mass and orbital angular momentum are conserved.
If you let mass leave the system, as it often does, and carry away some specific angular momentum, as it…
February 27, 2009
have you ever wondered what it is that graduate students do?
yeah, me too.
Well, know you can find out, from the horses' mouth
thursday afternoon was dedicated to a rapid fire "so, what have the graduate students been up to" as five of the students here at the program gave presentations on their…
February 27, 2009
Is the title of the talk Juan Maldacena gave thursday morning.
I missed the live delivery, due to my deplorable inability to be in two different places at the same time, but, as always webcast video and podcast are here
Enjoy.
Ok, it is string theory, but Juan always gives good talks.
Or he did the…
February 26, 2009
to the Astronomy Unit of the SB Natural History Museum, and the UCSB Circus of Physics
good show
but, guys, next time calculate the EMF first, or even just do a dry run, taking the head off the physicist's daughter would sooooo not have been a career move...
worked out well as it happened though
February 26, 2009
there was a legal case in Iceland a few years ago, it was an convoluted property rights case, can't remember the details, but it involved who had ownership when there was delivery but no payment nor explicit assumption of ownership and then a third party intercedes
anyway, the interesting thing…
February 26, 2009
so apparently insurance conglomerate giant AIG is on the verge of bankruptcy, again, despite something of order $200 billion bailout from the US, which now owns 79.9% of the company
the news solution is to request the US government guarantee the outstanding CDS that AIG issued
I propose a solution…
February 26, 2009
FSP tells it like it is: where there is nothing for money, and the lads are expensive
pay cuts, btw, are globally a bad idea, even if they are tempting locally
they are massively deflationary, because the cut generally all goes to discretionary spending, - a university doing cross-the-board pay…
February 26, 2009
yesterday I missed the post-Newtonian discussion, which is a bummer, but I was busy explaining to a hoard of pre-Ks why Mars looked green...
so now we go back to blowing things up
yes, it turns out that not all whites are the same, and trying to project onto that shade of white which has just a…
February 24, 2009
CR has a fascinating video from KCET on "trashout"
the poingancy and waste that comes from foreclosure and peoples' inability to cope
video is here
the waste, the trashing of furniture and equipment and items is horrendous,
but the cost in labour of slowing down and sorting through the stuff, and…
February 24, 2009
our topic for today is to find the best paper on globulars published since the workshop started
sadly I'm only up to 2007 on astro-ph
My nomination of this paper failed to win the prize, due to the excessive integrity of the judge
PS: I WON!
WOO HOO!
Ok, it was the razzie.
But I like it.
The…
February 24, 2009
What Julianne said.
It is not like going out into the Real World is a very promising career track right now.
February 24, 2009
is the Light of an Oncoming Train
classic
haven't had gratuitous youtube blogging for a while
Pugh! Pugh!
Barney, McGrew!
Cuthbert, Dibble, Grub!
February 24, 2009
NASA's Orbiting Carbon Observatory had a launch failure.
Taurus launch out of Vandenberg last night, tried to stay up to see if I could see the launch - often possible from the area - but I crashed before scheduled launch time.
Apparently payload failed to separate after stage burnout and the…
February 23, 2009
In the Good Old Days, Globular Clusters were simple things: spherical, relaxed, coeval and homogenous.
Not so much anymore.
The thorny issue of multiple populations keeps coming up at the workshop.
They're there, something is going on, but what, and how, and Y?
M13 embiggen
Guest author
Natalie…
February 23, 2009
ipsos custodes?
The guardians of the finances, to be specific.
I infer, reading on the Net, that US Treasury Secretary Geithner has not got round to nominating under and assistant secretaries for the various Treasury Offices.
So, they are either vacant, or staffed by holdovers from the previous…
February 23, 2009
apparently citigroup is pushing for a deal whereby the US government's current preferred stock holding in the company would be converted to common stock
the catch is that for about $45 billion in preferred stock the US would get less than 50% of the company, to avoid the stigma nationalization the…
February 23, 2009
New week, and a new set of topics for us to contemplate.
This week we hear from the grad students, who will tell us what it is they have actually been doing all this time, scientifically...
Tom is here! For a flying visit.
We may go post-Newtonian, and we may meander back through stellar evolution…
February 20, 2009
I've never seen a green star
I hope to never see one
but I can tell you anyhow
I'd rather model it than observe it...
if you have a bunch of stars of some age, or range of ages, and composition
with the stars all different mass over some range of masses, and
maybe some binaries and peculiar stars…
February 20, 2009
Yesterday we talked about triples.
It is an interesting thing that as we seem to not find any binaries in clusters, we do find triples... hmm.
First Rosemary discussed stability of triples - dynamical stability of isolated triples to internal spontaneous ejection - looking at analytic criteria…
February 20, 2009
the disbursement of the stimulus funding through the science agencies is going to get real interesting
some disparate word has reached me on the stimulus funding
first, the NSF divisions won't hear for a while, like next month, how much they individually get to push out the door (NIH might be…
February 19, 2009
I think I am having flashbacks
youtube, To The Rescue!
This was important mood music at a tender age...
late night parties with cider and harsh red wine in North Oxford.
February 19, 2009
Say it is not so:
Brio near bankruptcy
Brio, yes, Brio makes proper toys, out of wood.
Not junky injection molded plastic crap.
Wah.
February 19, 2009
word going around that Hubble servicing mission scheduled for May is in danger of being reconsidered because of higher mission risk
haven't seen the memo, but it went around:
due to the Iridium vs Kosmos collision there is concern that higher debris levels in LEO make SM4 too risky, and it is to…
February 19, 2009
While I was galavanting about the southland yesterday, the program moved on and
John compared N-body and Monte Carlo (video and podcast)
and Sverre and Rainer continued with the theme (video and podcast)
today we move onto triples
'cause you got to know that if two stars are good, three stars are…
February 17, 2009
long weekend over, and we're back at it.
today's topic is GRBs
and what, you might ask, do they have to do with clusters...?
Well, Bob, as you know, there are two types of gamma-ray bursters, or maybe three depending on how you count
type I and type II the long and the short
"Some say" that short…
February 13, 2009
ok, thomas.loc.gov now has the final version of the stimulus bill as being put to the vote to be sent to Obama - this is the House/Senate conference compromise plus extra bits the Speaker's office insisted upon after being unhappy with the Senate prematurely announcing agreement.
It is good for…
February 12, 2009
Latest on white dwarfs in globulars from Brad, John and Stefan.
White Dwarfs in Globular Clusters - Hansen - video and podcast
White Dwarfs in Globular Clusters - Fregeau and Rosswog - video and podcast
As we learned this morning, white dwarf cooling gives an absolute age indicator, essentially…