Parkes observations for project P926 semester 2016APRS_01

Millisecond pulsars (MSPs) are fast-spinning neutron stars, with spin periods P<=10 seconds, spun up by accretion from a companion star. Several binary MSPs are in eclipsing systems with tight orbits, and with light and partially (Red Backs) or nearly fully (Black Widows) ablated companions. Very few of such systems were known before a serendipitous discovery of gamma-ray sources by the Fermi gamma-ray observatory, some of which have been later identified as radio pulsars. Optical/near-IR and X-ray observations of the unidentified Fermi source 3FGL J2039.6-5618 allowed to identify it as a tight binary system. Both optical and X-ray light curve features a double-peak modulation which is consistent with what is already observed in other Red Back systems. Therefore, 3FGL J2039.6-5618 is probably a new Red Back system, yet undetected as radio or gamma-ray MSP. In radio, no potential counterpart to 3FGL J2039.6-5618 was found in previous attempts to detect radio pulsations from this source, which is again consistent with RB systems being elusive radio targets. The discovery of radio pulsations from 3FGL J2039.6-5618 will confirm the identification of the gamma-ray source as a MSP, and will play a key role in searching for yet undetected gamma-ray pulsations.