Last week in the cosmos

[January 13, 2003] - Last week seemed to truly be a big week for the cosmos. And why not? As the American Astronomical Society meetings were in session, a lot of things cosmic had special occasion to bubble to the surface. News included test results on Einstein’s oft-stated equations, Hubble space telescope renderings of very young galaxies, and the sighting of a planet in Sagittarius.

To start things off, astronomers from the Harvard-Smithsonian Center for Astrophysics in Cambridge said they had detected a planet far off in the constellation Sagittarius. The Harvard-Smithsonian folks found what they found using the method of photometric monitoring of stars, with the OGLE-TR-56b planet coming into view in relation to the star OGLE-TR-56. Planet discoveries outside, as also inside, of our own solar system have not been without controversy. About 100 extrasolar planets are presently known, as estimated by Harvard-Smithsonian.

This object is said to be part of the first planetary system found outside of the Orion arm of the Milky Way.

Photometric monitoring is described by a Harvard-Smithsonian team leader as a better way to detect new worlds. In fact, new methods are probably needed. That is because possible planets do not create light of their own; they are only seen in reflected light; and they may tend  to circle stars very, very far away.

In the past, radial velocity Doppler measurements of nearby wobbling stars and astrometric measurements of slight star motion,  have been used to find planets. Key to the photometric measuring techniques of the Harvard-Smithsonian researchers is the search for planets in transit. Eliminating bad candidates was an important step to narrowing the workers’ search.

On another front, the refurbished Hubble is uncovering new objects, left and right. It has fixed its gaze on the Abell galaxy cluster some 2.2-billion light years from home. The cluster field has a massive gravitational pull, “acting as a magnifying lens” for even more distant object that lurk beyond, say researchers. Up to 13 billion light years away, perhaps.

Reported last week was the work of University of Missouri scientists who applied the so-called quasar test to the speed of light, and found Einstein’s theory of relativity still standing. Transit came into play here, as the U of Missouri science fellows focused their efforts on measuring the effects of gravitational fields of moving bodies on radio and light waves when, one day in September last year, Jupiter passed  in front of distant quasar J0842. Groups of telescopes in an interferometer array worked to pinpoint the quasar’s position.

Hubble’s new insights wet the appetite for the upcoming (2010) launch of the James Webb Space Telescope. Use of gravitational lensing, uncovered in many masses of dark matter, may give better views of far of galaxies, and a better view on the birth of the universe.

Also noted: Some end-of-last-year results. To wit: Berkeley and Case Western researchers published the first data from the ACBAR Arcminute Cosmology Bolometer Array Receiver situated on the Viper polar radio telescope. It has been looking for cosmic microwave background (CMB) electromagnetic radiation that may indicate the condition of the Universe at its birth. Also late last year, U. of Chi. workers saw that the CMB could be polarized. They used polar radio telescopes in a Degree Angular Scale Interferometer (DASI) chain to measure, naturally, that which is polar.

Related
American Astronomical Society Meeting
US National Radio Astronomy Observatory
Speed of gravity and light equal -Nature.com, Jan 8, 2003
A planet most distant observed - HSCFA, Jan 6, 2003
Hubble finds early galaxies -New Scientist, Jan. 3, 2003

Last update: 4/12/2003; 11:47:32 AM.