Alex Filippenko's Talk at Astronomy Institute (IA-UNAM)

This picture is from another Filippenko's talk.

Friday December 11, with some of the five million people walking towards Tepeyac Hill Basilica to celebrate Our Lady Guadalupe's birthday; we arrived to Mexico City, where astronomer Alexei V. Filippenko presented his last results at the University City (CU, by its initials in Spanish) to the Astronomy Institute faculty and students.

The talk is based on work contained in three papers, with data taken over the past decade, with 10 years more of work to get the robotic telescope built and working.

He presented two new results:

For nearby supernovae Ia, they found a correlation between the rate per unit galaxy mass and galaxy mass: the more massive the galaxy, the smaller the rate per unit mass; if multiplied by each galaxy's mass, the rate increases with mass. More supernovae are produced in big galaxies.

The second result is the formula:

dN/dt ~ (1 + z)³

where z measures distance, and t time: the greater the z, the farther the exploding star, and N is the number of observed core collapsed supernovae.

Astronomer Xavier Hernández from IA-UNAM, expressed the opinion that the first result may be biased by using a reference galaxy mass of 4x10¹⁰ solar masses, which is big for this type of supernovae Ia.

Filippenko believes their result is the best they can get with their data set, which has been collected for ten years, and is the biggest sample obtained by a single group.

As it happens, there are not that many galaxies with lower masses producing supernovae they can detect with their robotic telescope.

Previously an amateur Australian astronomer had the nearby supernovae record. The religious minister Evans is a human "robot" to detect visible nearby supernovae.

Now Alex's group has the nearby supernovae Ia biggest professional sample in the world. To collect this amount of exploding star sightings, systematically characterized, their KAIT robot was used.

Alex then presented in this talk, and at a previous one this last summer, the results of the analyses done by his group.

Many of us expect all their analyses and results; we'll know more on these stars so important to study the "Accelerated Universe", that his group HZT, and SCP; discovered in 1998.

With talks in the "Sinfonía del Mar" open air venue this Monday, December 14, at 18:00 hrs in Acapulco, and Wednesday, December 16, in Chilpancingo at 11:00 hrs. in the SNTE auditorium; both with the title "El Universo en Expansión" and presented by this UC-Berkeley astronomer, and translated by me, we formally finish the activities of the International Year of Astronomy-2009.

I think it is appropriate that we celebrate four centuries of Galileo Galilei's use in 1609 of a telescope in Astronomy, with talks based on the use of a Newtonian telescope, invented later, and for the invention of which, Isaac Newton was accepted to the London Royal Society, with these talks of the great American astronomer Alexei V. Filippenko, recently elected to the National Academy of Sciences of his country, due in great part for work done with this robotic telescope built and managed by the group of astronomers he directs.

I want also to report that Professor Manuel Peimbert Sierra, present at the UNAM talk this Friday, is a corresponding member of this scientific American society, and that he published the paper on which the astronomer Filippenko, based his Ph.D. thesis at Caltech, under the direction of Wallace Sargent.

I wish these efforts to promote Astronomy, serve as inspiration to Mexican young people to pursue this passionate way of life.

Go see him, his students say:

"Filippenko is the greatest professor you'll meet ... TAKE THIS CLASS!!!!!"