Compact binary millisecond pulsars (nicknamed “spiders”) are a growing class of neutron stars: more than 100 systems are known in the Galactic field, including more than 30 candidates where pulsations have not been detected. Here we report the results of an optical follow-up of two spider pulsar candidates: 2FGL J0846.0+2820 and 4FGL J0935.3+0901
DetailsOn January 14th, 2026, Marco Turchetta successfully defended his PhD thesis at NTNU! Thesis title: “Hunting Spider Millisecond Pulsars in the Optical Sky” Trial lecture: “Supernovae” Main supervisor: Manuel Linares Co-supervisor: Karri Koljonen Many thanks to both opponents in the committee (Nathalie Degenaar and Teo Muñoz-Darias) for coming to Trondheim, and for their questions and comments.…
Details
Spider pulsars are known to exhibit orbital modulation of their flux across the entire electromagnetic spectrum, from radio to X-rays. Over the past decade, gamma-ray orbital modulation (GOM) has been discovered in a handful of spiders, but its origin remains largely unknown. Because GOM is very subtle, its detection requires high photon statistics and precise…
DetailsCompact binary millisecond pulsars, also known as “spiders”, host the most massive neutron stars ever observed to date. Expanding the currently known spider population holds the key to determining the maximum neutron star mass, which has crucial implications for astrophysics, nuclear physics and gravitational wave astronomy. Searching for the variable optical emission of their companions can reveal a radio-obscured population of spiders. In the linked article, we present the results of our COmpact BInary Pulsar…
DetailsWe have compiled SpiderCat—the first comprehensive catalog of all publicly known spiders in the Galactic field. The catalog brings together radio timing data and multi-wavelength properties for every known system, currently encompassing 111 spiders and candidates across the main subclasses of redbacks and black widows, as well as rarer types such as transitional, huntsman, and…
DetailsIn recent years, the LHAASO detector has opened a new window to the very and ultra-high energy Galactic gamma-ray sky, revealing numerous sources capable of emitting in this energy range. However, most of these sources remain unidentified. At the same time, the IceCube detector has finally established the existence of a Galactic neutrino signal, which…
DetailsSpiders are eclipsing millisecond pulsar binaries in which the pulsar ablates its low-mass companion; they are classified as black widows or redbacks based on companion mass. PSR J1932+2121 is a recently discovered Galactic-field redback millisecond pulsar (MSP) with a spin period of 14.2 ms, significantly slower than other known redbacks, and an unusually high surface…
DetailsThe process of accretion onto compact objects and its role in the production of relativistic, collimated jets remains a major open question in astronomy. Transitional millisecond pulsars (tMSPs) provide a rare opportunity to study the formation of relativistic jets in neutron stars that experience low-level accretion yet possess strong magnetic fields. By analyzing archival multiwavelength…
DetailsSpiders are millisecond pulsars in compact binary systems. The variable optical emission from their companion stars reveals how the relativistic pulsar wind irradiates the companion and interacts with its outflowing matter. By modelling this optical emission, we can precisely constrain the fundamental parameters of spiders and find super-massive neutron stars, which are usually hosted in…
DetailsCompact millisecond pulsar (MSP) binaries are crucial for understanding the formation of massive pulsars and the boundary between neutron stars (NSs) and black holes (BHs). Often referred to as “spiders” due to the cannibalistic interaction between the pulsar and its companion, these systems are broadly categorized into redbacks (RBs, with companion masses between 0.1 and…
Details