Posted on: Monday, June 28, 2004
Telescope studies supernovas
By Timothy Hurley
Advertiser Staff Writer
An international group of astronomers and astrophysicists is taking a closer look at supernovas with a powerful new tool mounted on a University of Hawai'i telescope atop Mauna Kea.
The Supernova Integral Field Spectrograph, or SNIFS, achieved "first light" earlier this month when the new instrument locked on to its first astronomical target — a Type Ia supernova in the constellation Cygnus. Previous measurements of Type Ia supernovas led to the discovery that the universe is expanding at an increasing rate.
Analysis of the initial data, plus a separate observation of another supernova June 20, confirm that the spectrograph — while still in its commissioning phase — is meeting its design goals as a remarkable new tool for observing supernovas, officials said.
The SNIFS is designed to examine supernovas by simultaneously obtaining more than 200 spectra of each target, its home galaxy and the nearby night sky.
The instrument is a key part of the work being done by the international Nearby Supernova Factory, a project started by the Department of Energy's Lawrence Berkeley National Laboratory.
The project's goal is to find and study more than 300 nearby Type Ia supernovas to more precisely measure the expansion rate of the universe.
"Better knowledge of these extraordinarily bright and remarkably uniform objects will make them even better tools for measuring the cosmos," said astronomer Greg Aldering of the Berkeley lab's Physics Division.
"Type Ia supernovas are the key to understanding the mysterious dark energy that's causing the universe to expand ever faster."
The body of the SNIFS instrument was built by the project's French collaborators, while the Berkeley lab, with help from Yale University, developed the cameras used to detect the light from SNIFS. The University of Chicago developed instruments to monitor the performance of the spectrograph.
Flown to Hilo in March and assembled in working order at sea level, SNIFS was taken apart, carried to the summit of Mauna Kea and reassembled on UH's 88-inch telescope April 6. Two months of engineering to align and calibrate the instrument on the telescope preceded observation of supernova in the Cygnus constellation, followed by Sunday's observation of a supernova in the constellation Serpens, the snake.
Remote control of the telescope and spectrograph was first accomplished from Hilo and is now being done from the Berkeley lab and France.
Reach Timothy Hurley at thurley@honoluluadvertiser.com or (808) 244-4880.
