Astrophysics at St.Andrews
Lead Research Organisation:
University of St Andrews
Department Name: Physics and Astronomy
Abstract
Our Galaxy contains many fossils of its formation history. Smaller galaxies that collided with the Milky Way long ago formed streams of stars that still linger as fossils of the Galaxy's formation, orbiting in the gravitational field of the Galaxy's primordial dark-matter halo. From 2011 the GAIA mission will map the positions and motions of these streams. We will develop new techniques to use data from GAIA to map the dark matter, and to test whether conventional theories of gravity work as expected at large distances. Clusters of new stars and planetary systems are constantly forming inside the dark clouds of gas and dust that delineate the Milky Way's spiral arms. In the biggest clusters, stars form that are up to 100 times as massive as the Sun. These massive stars burn so brightly that they are clearly visible in neighbouring galaxies. Many of them are binary stars. Our measurements of their mutual eclipses and spectra will reveal their sizes and temperatures, and hence the distances to the nearest galaxies. We do not yet understand how these massive stars form, or why so many of them are binaries. We will simulate how the most massive and hottest stars manage to form despite the tendency of their radiation fields to blow away the gas that feeds them. We also aim to find out how their winds, and the shock waves from the supernova explosions that eventually blow them apart, affect neighbouring gas clouds, perhaps triggering new bursts of star formation. The dark clouds where stars form contain needle-like dust grains that line up with the Galaxy's magnetic fields and polarize radiation passing through them. We will measure the polarization of infrared and mm-wave radiation coming from regions where cloud material is just beginning to form new stars, to discover what is happening to the magnetic field and to the grains themselves as the star condenses. Newly-born stars are surrounded by flat, rotating discs of gas and dust, which persist for two or three million years. As planets form in the disc material, some gas continues to feed the growing star, which at this stage possesses a strong magnetic field. We can now map these stars' magnetic fields using new instruments. We will use these maps to predict how the magnetic field acts to channel material into streams, and how the field structure regulates the flow rate on to the star and the star's spin. We will seek out rapidly rotating young stars near the Sun, in remnants of star clusters that formed up to 50 million years ago but fell apart. By this age the discs have gone, but an enigmatic fossil remnant of earlier processes lingers in their spin rates. Among otherwise identical stars in the same cluster, some spin much faster than others. We want to know if this difference in spin rate is a clue as to how many stars possess planetary systems, or if the difference originates in some peculiarity of the stars' magnetic fields. We will map the magnetic fields of the fast rotators and their more slowly-rotating siblings, to see if there is a difference in the rate at which hot gas flowing out along the field lines can carry away the star's spin. Finally, we will seek out planetary systems around nearby and distant stars. We are working with astronomers at several other institutions to monitor the brightnesses of hundreds of thousands of nearby stars, in order to pick out tiny dips in light caused by close-orbiting Jupiter-sized planets passing in front of their parent stars. We aim to discover dozens of such planets, and to measure their sizes, masses and temperatures. We will also search for planets further from their stars, by monitoring distant stars whose light is being temporarily magnified by the gravitational field of a foreground star. Distortions in the resulting light variation have already revealed Jupiter-mass planets around a couple of these foreground stars. We aim to find many more using a network of new robotic telescopes.
Organisations
Publications
Buchhave L
(2016)
A 1.9 EARTH RADIUS ROCKY PLANET AND THE DISCOVERY OF A NON-TRANSITING PLANET IN THE KEPLER-20 SYSTEM*
in The Astronomical Journal
Scandariato G
(2013)
A coordinated optical and X-ray spectroscopic campaign on HD 179949: searching for planet-induced chromospheric and coronal activity
in Astronomy & Astrophysics
Collier Cameron A
(2006)
A fast hybrid algorithm for exoplanetary transit searches
in Monthly Notices of the Royal Astronomical Society
Halle A
(2008)
A Nonuniform Dark Energy Fluid: Perturbation Equations
in The Astrophysical Journal Supplement Series
Bentz M
(2006)
A Reverberation-based Mass for the Central Black Hole in NGC 4151
in The Astrophysical Journal
Fares R
(2013)
A small survey of the magnetic fields of planet-host stars?
in Monthly Notices of the Royal Astronomical Society
Poulton C
(2008)
A Spitzer survey of young stellar objects in the Rosette Molecular Cloud
in Monthly Notices of the Royal Astronomical Society
Smith A
(2009)
A SuperWASP search for additional transiting planets in 24 known systems
in Monthly Notices of the Royal Astronomical Society
Kains N
(2009)
A systematic fitting scheme for caustic-crossing microlensing events
in Monthly Notices of the Royal Astronomical Society
Sicilia-Aguilar A
(2015)
Accretion dynamics of EX Lupi in quiescence The star, the spot, and the accretion column?
in Astronomy & Astrophysics
Clarke C
(2008)
Accretion-driven core collapse and the collisional formation of massive stars
in Monthly Notices of the Royal Astronomical Society
Dominik M
(2007)
Adaptive contouring - an efficient way to calculate microlensing light curves of extended sources
in Monthly Notices of the Royal Astronomical Society
Nisi RS
(2014)
An altitude and distance correction to the source fluence distribution of TGFs.
in Journal of geophysical research. Space physics
Shan H
(2008)
An analytic model for non-spherical lenses in covariant MOdified Newtonian Dynamics
in Monthly Notices of the Royal Astronomical Society
Dominik M
(2007)
An anomaly detector with immediate feedback to hunt for planets of Earth mass and below by microlensing
in Monthly Notices of the Royal Astronomical Society
Hellier C
(2009)
An orbital period of 0.94 days for the hot-Jupiter planet WASP-18b.
in Nature
Matthews B
(2007)
An Unbiased Survey of 500 Nearby Stars for Debris Disks: A JCMT Legacy Program
in Publications of the Astronomical Society of the Pacific
ZHAO H
(2011)
AN UNEVEN VACUUM ENERGY FLUID AS ?, DARK MATTER, MOND AND LENS
in Modern Physics Letters A
Dominik M
(2008)
ARTEMiS (Automated Robotic Terrestrial Exoplanet Microlensing Search): A possible expert-system based cooperative effort to hunt for planets of Earth mass and below
in Astronomische Nachrichten
Hilditch R. W.
(2007)
Astrophysical parameters forthe eclipsing binary IZ Persei
in OBSERVATORY
Angus G
(2006)
Can MOND take a bullet? Analytical comparisons of three versions of MOND beyond spherical symmetry Comparing three versions of MOND
in Monthly Notices of the Royal Astronomical Society
Novati S
(2009)
CANDIDATE MICROLENSING EVENTS FROM M31 OBSERVATIONS WITH THE LOIANO TELESCOPE
in The Astrophysical Journal
Bonomo A
(2014)
Characterization of the planetary system Kepler-101 with HARPS-N A hot super-Neptune with an Earth-sized low-mass companion
in Astronomy & Astrophysics
Vanderburg A
(2015)
CHARACTERIZING K2 PLANET DISCOVERIES: A SUPER-EARTH TRANSITING THE BRIGHT K DWARF HIP 116454
in The Astrophysical Journal
Clark P
(2007)
Clump lifetimes and the initial mass function
in Monthly Notices of the Royal Astronomical Society
Dobbs C
(2007)
Clumpy and fractal shocks, and the generation of a velocity dispersion in molecular clouds
in Monthly Notices of the Royal Astronomical Society
Clark P
(2006)
Clumpy shocks and the clump mass function
in Monthly Notices of the Royal Astronomical Society
Zhao H
(2007)
Coincidences of Dark Energy with Dark Matter: Clues for a Simple Alternative?
in The Astrophysical Journal
Angus G
(2007)
Cold dark matter microhalo survival in the Milky Way CDM microhalo survival in the Milky Way
in Monthly Notices of the Royal Astronomical Society
Bonnell, I A
(2008)
Competitive accretion and the formation of massive stars
in Pathways through an eclectic universe: proceedings of a conference held at Santiago del Teide, Tenerife, Spain, 23-27 April 2007 to celebrate John Beckman's 40 years in astrophysics
Zhao H
(2006)
Concordance of Kinematics and Lensing of Elliptical Galaxies with WMAP Cosmology
in Chinese Journal of Astronomy and Astrophysics
ZHAO H
(2012)
CONSTRAINING TEVES GRAVITY AS EFFECTIVE DARK MATTER AND DARK ENERGY
in International Journal of Modern Physics D
Jardine M
(2008)
Coronal structure of the classical T Tauri star V2129 Oph
in Monthly Notices of the Royal Astronomical Society
Zhao H
(2010)
DARK FLUID: A UNIFIED FRAMEWORK FOR MODIFIED NEWTONIAN DYNAMICS, DARK MATTER, AND DARK ENERGY
in The Astrophysical Journal
Greaves J
(2009)
Debris discs around nearby solar analogues
in Monthly Notices of the Royal Astronomical Society
Jeffers S
(2006)
Dense Spot Coverage and Polar Caps on SV Cam
in Astrophysics and Space Science
Poulton C
(2006)
Detecting a rotation in the Eridani debris disc
in Monthly Notices of the Royal Astronomical Society
Grunblatt S
(2015)
DETERMINING THE MASS OF KEPLER-78b WITH NONPARAMETRIC GAUSSIAN PROCESS ESTIMATION
in The Astrophysical Journal
Dunstone N
(2008)
Differential rotation on both components of the pre-main-sequence binary system HD 155555
in Monthly Notices of the Royal Astronomical Society
Collier Cameron A
(2007)
Differential rotation on rapidly rotating stars
in Astronomische Nachrichten
Gillon M
(2009)
Discovery and characterization of WASP-6b, an inflated sub-Jupiter mass planet transiting a solar-type star
in Astronomy & Astrophysics
Beaulieu JP
(2006)
Discovery of a cool planet of 5.5 Earth masses through gravitational microlensing.
in Nature
Gaudi B
(2008)
Discovery of a Jupiter/Saturn Analog with Gravitational Microlensing
in Science
Xiang Y
(2014)
Distribution and evolution of starspots on the RS CVn binary II Pegasi in 2004
in Monthly Notices of the Royal Astronomical Society
Moeckel N
(2009)
Does subcluster merging accelerate mass segregation in local clusters?
in Monthly Notices of the Royal Astronomical Society
Skelly M
(2009)
Doppler images and chromospheric variability of TWA 17
in Monthly Notices of the Royal Astronomical Society
Skelly M
(2008)
Doppler images and chromospheric variability of TWA 6
in Monthly Notices of the Royal Astronomical Society
Rice W
(2006)
Dust filtration at gap edges: implications for the spectral energy distributions of discs with embedded planets
in Monthly Notices of the Royal Astronomical Society
Hilditch R
(2006)
Eclipsing Binaries in Local Group Galaxies
in Astrophysics and Space Science
De Mink S
(2007)
Efficiency of mass transfer in massive close binaries Tests from double-lined eclipsing binaries in the SMC
in Astronomy & Astrophysics
| Description | Not applicable this year |
| Exploitation Route | Not applicable this year |
| Sectors | Education |