Massive Stars as Cosmic Engines through the Ages (2008)
Journal Article
Hirschi, R. (2008). Massive Stars as Cosmic Engines through the Ages. Proceedings of the International Astronomical Union, 3-16. https://doi.org/10.1017/S1743921308020292

Some useful developments in the model physics are briefly presented, followed by model results on chemical enrichments and WR stars. We discuss the expected rotation velocities of WR stars. We emphasize that the (C+O)/He ratio is a better chemical in... Read More about Massive Stars as Cosmic Engines through the Ages.

Spatial Distribution of Nucleosynthesis Products in Cassiopeia A: Comparison Between Observations and 3D Explosion Models (2008)
Presentation / Conference Contribution
(2008, July). Spatial Distribution of Nucleosynthesis Products in Cassiopeia A: Comparison Between Observations and 3D Explosion Models. Presented at 10th Symposium on Nuclei in the Cosmos, Mackinac Island, Michigan, USA

We examine observed heavy element abundances in the Cassiopeia A supernova remnant as a constraint on the nature of the Cas A supernova. We compare bulk abundances from 1D and 3D explosion models and spatial distribution of elements in 3D models with... Read More about Spatial Distribution of Nucleosynthesis Products in Cassiopeia A: Comparison Between Observations and 3D Explosion Models.

Difficulties in Probing Nuclear Physics: A Study of Ti and Ni (2008)
Presentation / Conference Contribution
Hungerford, A., Fryer, C. L., Timmes, F. X., Young, P., Bennett, M., Diehl, S., Herwig, F., Hirschi, R., Pignatari, M., Magkotsios, G., & Rockefeller, G. (2008, July). Difficulties in Probing Nuclear Physics: A Study of Ti and Ni. Paper presented at 10th Symposium on Nuclei in the Cosmos, Mackinac Island, Michigan, USA

The nucleosynthetic yield from a supernova explosion depends upon a variety of effects: progenitor evolution, explosion process, details of the nuclear network, and nuclear rates. Especially in studies of integrated stellar yields, simplifications re... Read More about Difficulties in Probing Nuclear Physics: A Study of Ti and Ni.

44Ti and 56Ni in core-collapse supernovae (2008)
Presentation / Conference Contribution
Magkotsios, G., Timmes, F. X., Wiescher, M., Fryer, C. L., Hungerford, A., Young, P., Bennett, M., Diehl, S., Herwig, F., Hirschi, R., Pignatari, M., & Rockefeller, G. (2008, July). 44Ti and 56Ni in core-collapse supernovae. Paper presented at 10th Symposium on Nuclei in the Cosmos, Mackinac Island, Michigan, USA

We investigate the physical conditions where 44Ti and 56Ni are created in core-collapse supernovae. In this preliminary work we use a series of post-processing network calculations with parametrized expansion profiles that are representative of the w... Read More about 44Ti and 56Ni in core-collapse supernovae.

Developments in physics of massive stars (2007)
Presentation / Conference Contribution
Meynet, G., Ekström, S., Maeder, A., Hirschi, R., Georgy, C., & Beffa, C. Developments in physics of massive stars. Presented at Symposium S250: Massive Stars as Cosmic Engines

New constraints on stellar models are provided by large surveys of massive stars, interferometric observations and asteroseismology. After a review of the main results so far obtained, we present new results from rotating models and discuss compariso... Read More about Developments in physics of massive stars.

The ultra-compact binary candidate KUV 23182+1007 is a bright quasar (2007)
Journal Article
Southworth, J., Schwope, A., Gaensicke, B., & Schreiber, M. (2007). The ultra-compact binary candidate KUV 23182+1007 is a bright quasar. arXiv,

KUV 23182+1007 was identified as a blue object in the Kiso UV Survey in the 1980s. Classification-dispersion spectroscopy showed a featureless continuum except for a strong emission line in the region of He II 4686 A. This is a hallmark of the rare A... Read More about The ultra-compact binary candidate KUV 23182+1007 is a bright quasar.

The Keele–Exeter young cluster survey – I. Low-mass pre-main-sequence stars in NGC 2169 (2007)
Journal Article
Jeffries, R., Oliveira, J., Naylor, T., Mayne, N., & Littlefair, S. (2007). The Keele–Exeter young cluster survey – I. Low-mass pre-main-sequence stars in NGC 2169. Monthly Notices of the Royal Astronomical Society, 376(2), 580 -598. https://doi.org/10.1111/j.1365-2966.2007.11327.x

We have used R_C I_C CCD photometry from the Isaac Newton telescope and intermediate resolution spectroscopy from the Gemini North telescope to identify and characterise low-mass (0.15<M/M_sun<1.3) pre-main sequence stars in the young open cluster NG...

Kinematic structure in the young σ Orionis association (2006)
Journal Article
Jeffries, R., Maxted, P., Oliveira, J., & Naylor, T. (2006). Kinematic structure in the young σ Orionis association. Monthly Notices of the Royal Astronomical Society, 371(1), L6 - L10. https://doi.org/10.1111/j.1745-3933.2006.00196.x

We have used precise radial velocity measurements for a large number of candidate low-mass stars and brown dwarfs, to show that the young Sigma Ori ``cluster'' consists of two spatially superimposed components which are kinematically separated by 7 k... Read More about Kinematic structure in the young σ Orionis association.

Eclipsing Binaries in Open Clusters (2006)
Journal Article
Southworth, J., & Viggo Clausen, J. (2006). Eclipsing Binaries in Open Clusters. Astrophysics and Space Science, 304, Article 199–202. https://doi.org/10.1007/s10509-006-9110-3

Detached eclipsing binaries are very useful objects for calibrating theoretical stellar models and checking their predictions. Detached eclipsing binaries in open clusters are particularly important because of the additional constraints on their age... Read More about Eclipsing Binaries in Open Clusters.

Circumstellar discs in the young σ Orionis cluster (2006)
Journal Article
Oliveira, J., Jeffries, R., Van Loon, J., & Rushton, M. (2006). Circumstellar discs in the young σ Orionis cluster. Monthly Notices of the Royal Astronomical Society, 369(1), 272 -280. https://doi.org/10.1111/j.1365-2966.2006.10299.x

We present new K- and L'-band imaging observations for members of the young (3-5 Myr) sigma Orionis cluster, obtained with UIST at UKIRT. We determine (K-L') colour excesses with respect to the photospheres, finding evidence for warm circumstellar du... Read More about Circumstellar discs in the young σ Orionis cluster.

Synthesis of the Beryllium 3131A Spectral Region (2005)
Journal Article
Ashwell, J., F. Ashwell, J., Jeffries, R., D. Jeffries, R., & Smalley, B. Synthesis of the Beryllium 3131A Spectral Region. Manuscript submitted for publication

The Beryllium spectral region of the Sun, Procyon and 4 stars in the open cluster NGC6633 up to Teff = 7500K have been synthesised using ATLAS9 model atmospheres and the MOOG spectral synthesis program. The line list used for these syntheses has bee... Read More about Synthesis of the Beryllium 3131A Spectral Region.

Different convection models in ATLAS (2005)
Journal Article
Smalley, B. Different convection models in ATLAS. Manuscript submitted for publication

Convection is an important phenomenon in the atmospheres of A-type and cooler stars. A description of convection in ATLAS models is presented, together with details of how it is specified in model calculations. The effects of changing the treatment o... Read More about Different convection models in ATLAS.

Young stars and their circumstellar disks in the Sigma Orionis cluster (2004)
Presentation / Conference Contribution
M. Oliveira, J., D. Jeffries, R., Th. van Loon, J., & J. Kenyon, M. (2003, April). Young stars and their circumstellar disks in the Sigma Orionis cluster. Presented at Open Issues in Local Star Formation and Early Stellar Evolution, Ouro Preto, Minas Gerais, Brazil

The sigma Orionis cluster is a young association evolving under the disruptive influence of its massive O-star namesake. We are analysing this cluster as part of a program to characterise the influence of O-stars on the early stages of stellar evolut... Read More about Young stars and their circumstellar disks in the Sigma Orionis cluster.

Accurate fundamental parameters of eclipsing binary stars (2004)
Journal Article
Southworth, J., Smalley, B., Maxted, P., & Etzel, P. (2004). Accurate fundamental parameters of eclipsing binary stars. Proceedings of the International Astronomical Union, 2004(IAUS224), 548-561. https://doi.org/10.1017/S1743921305009324

The study of detached eclipsing binaries is one of the most powerful ways to investigate the properties of individual stars and stellar systems. We present preliminary masses, radii and effective temperatures for the eclipsing binary WW Aurigae, whic... Read More about Accurate fundamental parameters of eclipsing binary stars.

Eclipsing binaries in open clusters (2003)
Presentation / Conference Contribution
Southworth, J., Maxted, P., & Smalley, B. Eclipsing binaries in open clusters

Accurate physical parameters have been determined for two early-type detached eclipsing binaries in the open cluster h Persei (NGC 869). Masses accurate to 1.5% are derived from high-resolution spectroscopy and radii accurate to 4--6% have been obtai... Read More about Eclipsing binaries in open clusters.

No disks around low-mass stars and brown dwarfs in the young sigma Orionis cluster? (2002)
Journal Article
Oliveira, J., Jeffries, R., Kenyon, M., Thompson, S., & Naylor, T. (2002). No disks around low-mass stars and brown dwarfs in the young sigma Orionis cluster?. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361%3A20011778

We report on the analysis of 2MASS near-infrared data of a sample of low-mass stars and brown dwarfs in the sigma Orionis cluster. Youth and cluster membership have been spectroscopically confirmed using the Li I spectral line. We find little evidenc... Read More about No disks around low-mass stars and brown dwarfs in the young sigma Orionis cluster?.

Stream-fed accretion in intermediate polars (2002)
Journal Article
(2002). Stream-fed accretion in intermediate polars. Astronomical Society of the Pacific Conference Series,

I review the observational evidence for stream-fed accretion in intermediate polars. Recent work on the discless system V2400 Oph confirms the pole-flipping model of stream-fed accretion, but this applies only to a minority of the flow. The bulk of t... Read More about Stream-fed accretion in intermediate polars.

The first K2 roAp star: HD 24355 pulsating in a distorted quadruploe mode
Presentation / Conference
Smalley. The first K2 roAp star: HD 24355 pulsating in a distorted quadruploe mode. Presented at eismology of the Sun and the Distant Stars 2016 – Using Today’s Successes to Prepare the Future – TASC2 & KASC9 Workshop – SPACEINN & HELAS8 Conference

We present an analysis of the first K2 observations of a rapidly oscillating Ap (roAp) star, HD 24355. The star was discovered to be a roAp star by [1], with a frequency of 224.31 d-1 (2596.18 µHz; P = 6.4 min) and an amplitude of 1.51 mmag in SuperW... Read More about The first K2 roAp star: HD 24355 pulsating in a distorted quadruploe mode.

A Suzaku survey of iron lines in type 1 Active Galactic Nuclei
Thesis
A Suzaku survey of iron lines in type 1 Active Galactic Nuclei. https://keele-repository.worktribe.com/output/409098

Active galactic nuclei (AGN) are some of the most energetic objects which have ever been observed and each of these harbour a supermassive black hole at its centre. By looking at the X-ray emission from these nuclei, information can be gathered regar... Read More about A Suzaku survey of iron lines in type 1 Active Galactic Nuclei.

Carbon burning and hydrodynamic mixing uncertainties in stellar models
Thesis
Carbon burning and hydrodynamic mixing uncertainties in stellar models. https://keele-repository.worktribe.com/output/409122

The aim of this thesis is to investigate uncertainties in the input physics of stellar models that are relevant for the evolution of stars and the related nucleosynthesis, in particular the s-process. Nuclear reaction rates and mixing prescriptions i... Read More about Carbon burning and hydrodynamic mixing uncertainties in stellar models.