The VLT-FLAMES survey of massive stars: Nitrogen abundances for Be-type stars in the Magellanic Clouds

(2011)

Authors:

PR Dunstall, I Brott, PL Dufton, DJ Lennon, CJ Evans, SJ Smartt, I Hunter

On the association of ULXs with young superclusters: M82 X-1 and a new candidate in NGC 7479

(2011)

Authors:

R Voss, MTB Nielsen, G Nelemans, M Fraser, SJ Smartt

FRATs: A search for Fast Radio Transients with LOFAR

AIP Conference Proceedings 1357 (2011) 331-334

Authors:

S Ter Veen, H Falcke, R Fender, JR Hörandel, CW James, S Rawlings, P Schellart, B Stappers, R Wijers, M Wise, P Zarka

Abstract:

The FRATs project aims to detect single dispersed pulses from Fast Radio Transients with LOFAR in real-time. These pulses can originate from pulsars, RRATS and other classes of known or unknown objects. To detect these pulses a detection algorithm is being run on an incoherent beam from the different LOFAR stations. This incoherent beam has a wide field of view and can be formed parallel to other observations, such that both can run at the same time. A precise localisation is done by storing the data from each dipole. This gives an all-sky coverage with a spatial resolution of order arc seconds. The source is identified by making high time-resolution images. This is explained in more detail with preliminary results illustrating the methods. © 2011 American Institute of Physics.

Pulsars and fast transients with LOFAR

AIP Conference Proceedings 1357 (2011) 325-330

Authors:

B Stappers, J Hessels, A Alexov, K Anderson, T Coenen, T Hassall, A Karastergiou, V Kondratiev, M Kramer, J Van Leeuwen, JD Mol, A Noutsos, J Romein, P Weltevrede, R Fender, R Wijers

Abstract:

The LOw Frequency ARray is the first of the next generation of radio telescopes to be completed. It uses large numbers of small receptors and vast computing and data transport capabilities to achieve a high degree of sensitivity over large fields of view. It uses two different types of receptor to enable it to observe over the frequency range 10-260 MHz. Here we report on some of the capabilities of this telescope for pulsar and fast transient research. We also present some results of the commissioning work that we have been carrying out which highlight the exciting potential of this telescope. These include simultaneous imaging and pulsar observations, simultaneous observations spanning 30-8000 MHz, a large number of known pulsars detected in the high band and the detection of PSR B0809+74 down to a frequency of 16 MHz. © 2011 American Institute of Physics.

Planet Hunters: The First Two Planet Candidates Identified by the Public using the Kepler Public Archive Data

ArXiv 1109.4621 (2011)

Authors:

Debra Fischer, Megan Schwamb, Kevin Schawinski, Chris Lintott, John Brewer, Matt Giguere, Stuart Lynn, Michael Parrish, Thibault Sartori, Robert Simpson, Arfon Smith, Julien Spronck, Natalie Batalha, Jason Rowe, Jon Jenkins, Steve Bryson, Andrej Prsa, Peter Tenenbaum, Justin Crepp, Tim Morton, Andrew Howard, Michele Beleu, Zachary Kaplan, Nick vanNispen, Charlie Sharzer, Justin DeFouw, Agnieszka Hajduk, Joe Neal, Adam Nemec, Nadine Schuepbach, Valerij Zimmermann

Abstract:

Planet Hunters is a new citizen science project, designed to engage the public in an exoplanet search using NASA Kepler public release data. In the first month after launch, users identified two new planet candidates which survived our checks for false- positives. The follow-up effort included analysis of Keck HIRES spectra of the host stars, analysis of pixel centroid offsets in the Kepler data and adaptive optics imaging at Keck using NIRC2. Spectral synthesis modeling coupled with stellar evolutionary models yields a stellar density distribution, which is used to model the transit orbit. The orbital periods of the planet candidates are 9.8844 \pm0.0087 days (KIC 10905746) and 49.7696 \pm0.00039 (KIC 6185331) days and the modeled planet radii are 2.65 and 8.05 R\oplus. The involvement of citizen scientists as part of Planet Hunters is therefore shown to be a valuable and reliable tool in exoplanet detection.