6 papers
A Photometric Method for estimating CNO Abundances in Globular Clusters
David Peat, Raymond Butler
Stromgren indices v and b are combined with broad-band index I, and a new index p, the short wavelength half of the v band, to estimate CN 4215A molecular absorption in a sample of…
A new survey of variability in the core of M15 with TRIFFID-2
Seathrun O'Tuairisg, Raymond Butler, Andy Shearer +2
A two-week campaign of high-resolution imaging of the centre of M15 using the tip/tilt correcting TRIFFID-2 camera, followed by analysis with ISIS (image matching & subtraction sof…
PSR B1951+32 and PSR J0537-6910 - where are the optical counterparts?
R. F. Butler, A. Golden, A. Shearer +1
There remain several definitive gamma-ray pulsars that are as yet undetected in the optical regime. A classic case is the pulsar PSR B1951+32, associated with the complex CTB 80 SN…
A 2.14 ms Candidate Optical Pulsar in SN1987A
J. Middleditch, J. A. Kristian, W. E. Kunkel +10
We have monitored Supernova 1987A in optical/near-infrared bands from a few weeks following its birth until the present time in order to search for a pulsar remnant. We have found…
A Search for the Optical Counterpart of PSR B1951+32 in the Supernova Remnant CTB 80
Creidhe O'Sullivan, A. Shearer, M. Colhoun +8
Using time-resolved two-dimensional aperture photometry we have put upper limits on the pulsed emission from two proposed optical counterparts for PSR B1951+32. Our pulsed upper li…
Pulsed optical emission from Geminga
A. Shearer, A. Golden, S. Harfst +9
We present optical data which shows that G", the optical counterpart of the gamma-ray pulsar Geminga, pulses in B with a period of 0.237 seconds. The similarity between the optical…