The longest stellar eclipse lasts around 3.45 years and takes place in a binary star system called TYC 2505-672-1. The discovery was made by the Stassun Research Group, Vanderbilt University, USA, and published on 19 January 2016.
The eclipse takes place once every 69 years. From the viewpoint of an observer on Earth, the red giant component of the binary system is eclipsed by its companion star. The companion star - which the research team think could be a 'stripped red giant', which is on its way to becoming a white dwarf - is surrounded by a huge disc of opaque dust which blocks out almost all of the light from the red giant.
Prior to this discovery, the longest known stellar eclipse was between 640 and 730 days, and took place every 27 years in the binary system Epsilon Aurigae.
The research team behind the discovery of TYC 2505-672-1 consists of Joseph E. Rodriguez, Keivan G. Stassun, Michael B. Lund, Robert J. Siverd, Joshua Pepper, Sumin Tang, Stella Kafka, B. Scott Gaudi, Kyle E. Conroy, Thomas G. Beatty, Daniel J. Stevens, Benjamin J. Shappee and Christopher S. Kochanek. The research was published in the Astronomical Journal.
Photo: Jeremy Teaford / Vanderbilt University