We report the discovery of the millisecond pulsar PSR J2043+1711 in a search of a Fermi Large Area Telescope ( LAT ) source with no known associations , with the Nançay Radio Telescope .
The new pulsar , confirmed with the Green Bank Telescope , has a spin period of 2.38 ms , is relatively nearby ( d \la 2 kpc ) , and is in a 1.48 day orbit around a low mass companion , probably a He-type white dwarf .
Using an ephemeris based on Arecibo , Nançay , and Westerbork timing measurements , pulsed gamma-ray emission was detected in the data recorded by the Fermi LAT .
The gamma-ray light curve and spectral properties are typical of other gamma-ray millisecond pulsars seen with Fermi .
X-ray observations of the pulsar with Suzaku and the Swift /XRT yielded no detection .
At 1.4 GHz we observe strong flux density variations because of interstellar diffractive scintillation , however a sharp peak can be observed at this frequency during bright scintillation states .
At 327 MHz the pulsar is detected with a much higher signal-to-noise ratio and its flux density is far more steady .
However , at that frequency the Arecibo instrumentation can not yet fully resolve the pulse profile .
Despite that , our pulse time-of-arrival measurements have a post-fit residual rms of 2 \mu s. This and the expected stability of this system has made PSRÂ J2043+1711 one of the first new Fermi -selected millisecond pulsars to be added to pulsar gravitational wave timing arrays .
It has also allowed a significant measurement of relativistic delays in the times of arrival of the pulses due to the curvature of space-time near the companion , but not yet with enough precision to derive useful masses for the pulsar and the companion .
Nevertheless , a mass for the pulsar between 1.7 and 2.0Â M _ { \sun } can be derived if a standard millisecond pulsar formation model is assumed .
In this article we also present a comprehensive summary of pulsar searches in Fermi LAT sources with the Nançay Radio Telescope to date .