A search for pulsed IR and near-IR emission from PSR1937 + 214

Abstract

Backer et al.^1,2 discovered PSR1937+214 at radiowavelengths. Djorgovski³ identified a candidate optical counterpart with a red-sensitive CCD on a 1-m telescope, although he found nothing on the paper prints of the Palomer Sky Survey. Manchester et al.⁴ at the Anglo-Australian Telescope reported optical pulses from a field including Djorgovski's red candidate, although they have not confirmedthis. Their 3.5 arcs field barely included the pulsar position. Two of us (M.J.L. and G.H.R.) have found a bright IR flux of 12.3 mag at 2.2 µm, an image at the plate limit on the red-sensitive glass print of the Sky Survey, and CO absorption bands, all for the red candidate⁵. We report here that it is probably an ordinary red giant. We do not find statistically significant pulsations at the pulsar frequency or any harmonic up to the fourth in 6 to 8 arc s fields including both the red candidate and the radio pulsar positions.