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
Mortier A
(2016)
The HARPS search for southern extra-solar planets XXXIX. HD 175607, the most metal-poor G dwarf with an orbiting sub-Neptune
in Astronomy & Astrophysics
Díaz R
(2016)
The HARPS search for southern extra-solar planets XXXVIII. Bayesian re-analysis of three systems. New super-Earths, unconfirmed signals, and magnetic cycles ???
in Astronomy & Astrophysics
Motalebi F
(2015)
The HARPS-N Rocky Planet Search I. HD 219134 b: A transiting rocky planet in a multi-planet system at 6.5 pc from the Sun ?
in Astronomy & Astrophysics
Donati J
(2017)
The hot Jupiter of the magnetically active weak-line T Tauri star V830 Tau
in Monthly Notices of the Royal Astronomical Society
Smith A
(2006)
The impact of correlated noise on SuperWASP detection rates for transiting extrasolar planets
in Monthly Notices of the Royal Astronomical Society
Holzwarth V
(2006)
The impact of meridional circulation on stellar butterfly diagrams and polar caps Stellar butterfly diagrams and polar caps
in Monthly Notices of the Royal Astronomical Society
Gregory S
(2016)
The influence of radiative core growth on coronal X-ray emission from pre-main-sequence stars
in Monthly Notices of the Royal Astronomical Society
Ward-Thompson D
(2007)
The James Clerk Maxwell Telescope Legacy Survey of Nearby Star-forming Regions in the Gould Belt
in Publications of the Astronomical Society of the Pacific
Bonnell I
(2006)
The Jeans mass and the origin of the knee in the IMF
in Monthly Notices of the Royal Astronomical Society
Gettel S
(2016)
THE KEPLER-454 SYSTEM: A SMALL, NOT-ROCKY INNER PLANET, A JOVIAN WORLD, AND A DISTANT COMPANION
in The Astrophysical Journal
Donati JF
(2006)
The large-scale axisymmetric magnetic topology of a very-low-mass fully convective star.
in Science (New York, N.Y.)
Boardman N
(2016)
The low dark matter content of the lenticular galaxy NGC 3998
in Monthly Notices of the Royal Astronomical Society
West R
(2009)
THE LOW DENSITY TRANSITING EXOPLANET WASP-15b
in The Astronomical Journal
Gregory S
(2009)
The magnetic fields of accreting T Tauri stars
Collier Cameron A
(2009)
The main-sequence rotation???colour relation in the Coma Berenices open cluster
in Monthly Notices of the Royal Astronomical Society
Dressing C
(2015)
THE MASS OF Kepler-93b AND THE COMPOSITION OF TERRESTRIAL PLANETS
in The Astrophysical Journal
Denney K
(2006)
The Mass of the Black Hole in the Seyfert 1 Galaxy NGC 4593 from Reverberation Mapping
in The Astrophysical Journal
Bentley S
(2009)
The masses and radii of HD 186753B and TYC7096-222-1B: the discovery of two M-dwarfs that eclipse A-type stars
in Astronomy & Astrophysics
Gregory S
(2008)
The non-dipolar magnetic fields of accreting T Tauri stars The non-dipolar fields of T Tauri stars
in Monthly Notices of the Royal Astronomical Society
Shkolnik E
(2008)
The On/Off Nature of Star-Planet Interactions
in The Astrophysical Journal
Wang X
(2013)
The refined physical parameters of transiting exoplanet system HAT-P-24
in Research in Astronomy and Astrophysics
Wang X
(2014)
THE REFINED PHYSICAL PROPERTIES OF TRANSITING EXOPLANETARY SYSTEM WASP-11/HAT-P-10
in The Astronomical Journal
Tian L
(2009)
The relation between stellar mass and weak lensing signal around galaxies: implications for modified Newtonian dynamics
in Monthly Notices of the Royal Astronomical Society
Triaud A
(2009)
The Rossiter-McLaughlin effect of CoRoT-3b and HD 189733b
in Astronomy & Astrophysics
Smith R
(2009)
The simultaneous formation of massive stars and stellar clusters The formation of massive stars and clusters
in Monthly Notices of the Royal Astronomical Society
Morin J
(2008)
The stable magnetic field of the fully convective star V374 Peg
in Monthly Notices of the Royal Astronomical Society
Clark P
(2008)
The star formation efficiency and its relation to variations in the initial mass function
in Monthly Notices of the Royal Astronomical Society
Smith R
(2008)
The structure of molecular clouds and the universality of the clump mass function
in Monthly Notices of the Royal Astronomical Society
West R
(2009)
The sub-Jupiter mass transiting exoplanet WASP-11b
in Astronomy & Astrophysics
Haywood R
(2016)
The Sun as a planet-host star: proxies from SDO images for HARPS radial-velocity variations
in Monthly Notices of the Royal Astronomical Society
Christian D
(2006)
The SuperWASP wide-field exoplanetary transit survey: candidates from fields 23 h < RA < 03 h
in Monthly Notices of the Royal Astronomical Society
Donati J
(2006)
The surprising magnetic topology of Sco: fossil remnant or dynamo output?
in Monthly Notices of the Royal Astronomical Society
Rostron J
(2014)
The thermal emission of the exoplanet WASP-3b
in Monthly Notices of the Royal Astronomical Society
Angus G
(2007)
The velocity distribution of Sloan Digital Sky Survey satellites in Modified Newtonian Dynamics Velocity distribution of SDSS satellites
in Monthly Notices of the Royal Astronomical Society: Letters
Haffner L
(2009)
The warm ionized medium in spiral galaxies
in Reviews of Modern Physics
Pollacco D
(2006)
The WASP Project and SuperWASP Camera
in Astrophysics and Space Science
Pollacco D
(2006)
The WASP Project and the SuperWASP Cameras
in Publications of the Astronomical Society of the Pacific
Christian D
(2006)
The WASP project in the era of robotic telescope networks
in Astronomische Nachrichten
Anderson D
(2015)
THE WELL-ALIGNED ORBIT OF WASP-84b: EVIDENCE FOR DISK MIGRATION OF A HOT JUPITER
in The Astrophysical Journal
Holzwarth V
(2006)
Theoretical mass loss rates of cool main-sequence stars
in Astronomy & Astrophysics
Anderson D
(2014)
Three newly discovered sub-Jupiter-mass planets: WASP-69b and WASP-84b transit active K dwarfs and WASP-70Ab transits the evolved primary of a G4+K3 binary?†
in Monthly Notices of the Royal Astronomical Society
Hellier C
(2015)
THREE WASP-SOUTH TRANSITING EXOPLANETS: WASP-74b, WASP-83b, AND WASP-89b
in The Astronomical Journal
Indebetouw R
(2006)
Three-dimensional Models of Embedded High-Mass Stars: Effects of a Clumpy Circumstellar Medium
in The Astrophysical Journal
Zhao H
(2007)
Tidal Disruption of the First Dark Microhalos
in The Astrophysical Journal
Gentile G
(2007)
Tidal dwarf galaxies as a test of fundamental physics
in Astronomy & Astrophysics
Wyatt M
(2007)
Transience of Hot Dust around Sun-like Stars
in The Astrophysical Journal
Aigrain S
(2008)
Transiting exoplanets from the CoRoT space mission IV. CoRoT-Exo-4b: a transiting planet in a 9.2 day synchronous orbit
in Astronomy & Astrophysics
Deleuil M
(2008)
Transiting exoplanets from the CoRoT space mission VI. CoRoT-Exo-3b: the first secure inhabitant of the brown-dwarf desert
in Astronomy & Astrophysics
Faria J
(2016)
Uncovering the planets and stellar activity of CoRoT-7 using only radial velocities
in Astronomy & Astrophysics
Gentile G
(2009)
Universality of galactic surface densities within one dark halo scale-length.
in Nature
Description | Not applicable this year |
Exploitation Route | Not applicable this year |
Sectors | Education |