GBT23A-318

Continued monitoring of PSR J2108+45: a binary with a circumstellar environment

Abstract

We recently discovered the 6th radio pulsar/main-sequence star binary system, PSR J2018+45, with CHIME. The pulsar is in a 269-day orbit with a V~11 OBe companion in the Cygnus star-forming region. The pulsar stands out by disappearing from the 400-800 MHz observing band for large fractions of its 269-day orbit and by significant dispersion measure and scattering time variations, indicating a circumstellar disk or very dense stellar wind around the companion. Some of its individual pulses are bright enough to trigger the CHIME FRB backend, suggesting they might be strongly magnified by plasma lensing.
We will begin monitoring PSR J2018+45 with the GBT at higher frequencies (between L-band and X-band) in semester 2022B (GBT22B-269), which will cover approximately two thirds of the orbit. We request continued observations in the new semester, to cover the remaining portion of the orbit, with high cadence around in the days around the eclipse (16 May 2023), and using the UWB receiver in place of the L-band and S-band receivers.
We ask for a total of 53 hours of observation time, split into 30 sessions: 8 at high cadence around superior conjunction, and 22 spread over the rest of the orbit.

Investigators

Name	Institution
Georgia Lowes	Hull, University of
James McKee *	Hull, University of
Ingrid Stairs	British Columbia, University of
Chia Min Tan	Manchester, University of; McGill University
Bridget Andersen	Virginia, University of; McGill University
Vicky Kaspi	McGill University
Marten van Kerkwijk	Toronto, University of
Ue-Li Pen	Toronto, University of

* indicates the PI