August 2007 to May 2008

MOST SCIENTIFIC HIGHLIGHTS SINCE AUGUST 2007

Fourteen papers have appeared in print or been accepted in the last nine months. One was featured on the cover of the November issue of The Astronomical Journal. Here's some of what we've been doing with MOST in that time:

• Detection of two new Slowly Pulsating Be stars - a new class of pulsating variable stars which was discovered by MOST. UBC Ph.D. student Chris Cameron and Japanese theorist Hideyuki Saio led the effort to show how the pulsation frequencies of these stars can tell us how hot massive stars are spinning. This same duo also led the discovery of g-modes (buoyancy waves) in the massive star beta Canis Minoris - the coolest member of the class in which this type of pulsation has been observed.
• The fact that the Wolf-Rayet star HD 165763 - a precursor to a supernova - is remarkably constant has important implications for the understanding of how and why such stars pulsate. Tony Moffat (MOST Science Team member at the Université de Montréal and Sergey Marchenko of Western Kentucky University) led the study.
• The "hot Jupiter" orbiting closely around the star tau Boötis is triggering spots and flares in the stellar atmosphere beneath it, as MOST Science Team member Gordon Walker, former UBC undergrad and current University of Toronto Ph.D. student Bryce Croll, MOST Mission Scientist Jaymie Matthews and others on the MOST team have found. MOST is likely seeing the effects of tangling of the magnetic fields of the planet and star.
• Astronomers can measure the magnetic fields at the surfaces of other stars, but MOST is testing what those fields are like below the surface. University of Vienna graduate students Michael Gruberbauer and Dan Huber, working with theorist Hideyuki Saio and the MOST team, have used the vibrations of the magnetic pulsating stars gamma Equulei and 10 Aquilae to tell us what are the magnetic field strengths and geometries in the interiors of these stars - otherwise hidden from telescopic eyes.
• The heavily spotted star HD 189733 also hosts a transiting exoplanet. Eliza Miller-Ricci (a Harvard Ph.D. student) and Bryce Croll (a U of Toronto Ph.D. student) have performed separate analyses - timing the transits of the planet and mapping the spots on the star - to give us a unique glimpse at this system, including a sensitive search for Earth-mass and Earth-size planets.
• UBC undergraduate student Reka Moldovan and MOST Mission Scientist Jaymie Matthews have started a search for asteroids around the star HD 209458 based on MOST photometry. They are looking for the equivalent of the Trojan swarms of asteroids found camped out ahead of and behind Jupiter in its orbit in our Solar System.
• Red giants vibrate, but their vibrations are more complex than we used to think. Vienna Ph.D. student Thomas Kallinger and MOST Science Team member David Guenther (St. Mary's University) have led investigations of the pulsating red giants HD 20884 and epsilon Ophiuchi which show that they pulsate nonradially - i.e., they don't just expand and contract in the same way in all directions from the stellar centre. The pulsations of HD 20884 were discovered by MOST and the models of these red giants are helping us understand the late stages of the lives of stars like the Sun - looking into our own star's future.

29 May 2008

BUSY IN SPACE, BUSY ON EARTH

A BIT LAZY ON THE WEBSITE

Those of you who check the MOST website regularly may be forgiven for thinking MOST has been idle for many months, since there have been no updates. Nothing could be further from the truth. MOST and the MOST team have been very active and productive, but the Mission Scientist (also very busy) has been negligent in posting the latest news, publications and data on this site. Please check this page and the News page for the latest developments, the Science page for the scientific papers which have appeared, and the Public Data Archive on that page for the latest releases of MOST data.

Jaymie Matthews

MOST Mission Scientist