KIC 3542116

KIC 3542116 has a spectral type of F2V from spectroscopy taken at the Fred Lawrence Whipple Observatory. While the star does not show clear signs of being young, the scientists suspect the star to be young.^[1] The star is co-moving^[2] with a M1.9-type^[4] red dwarf called KOI-4987 (KIC 3542117); a planet candidate around this star, KOI-4987.01, is a false positive.^[5] This star has an 23 day rotation that leaks into the Kepler light curve of KIC 3542116.^[1]

The employment consultant and citizen scientists of the Planet Hunters project Thomas Jacobs did look through light curves of 201,250 target stars from the Kepler Space Telescope and found three potential transiting exocomets around KIC 3542116. Three more shallow transits were later discovered in the light curve.^[1][7] Transiting exocomets were already modelled in the 90s by A. Lecavelier Des Etangs et al. This team predicted a rounded triangular shape that is distinct from transiting exoplanets.^[8][9] The team of scientists found just such a shape, with a "steeper ingresses with positive curvature, followed by longer egresses with negative curvature" for the three deeper transits.^[1] The transits were later also detected in an automated search for exocomets.^[10] Another work did detect 8 transits in total (including previous detected transits). Modelling did show that the transits agree well with known comets from the Solar System, such as Halley's Comet, comet Hale–Bopp and C/2006 S3 (LONEOS). The shallow transits are produced by comets moving closer to the star (about 1 astronomical unit) and produce dust particles with a size of 0.1 and 20 μm. The deeper transits are produced by comets orbiting further away (around 5 astronomical units) and produce larger dust particles with a size greater than 5 μm. The study has shown that the shape of the transit is influenced by a varaiety of factors, such as particle size, distribution and distance to the star. The depth and duration of the transit is influenced by the dust productivity of the comet nucleus and the impact parameter. The dust productivity is higher for exocomets with shallow dips that orbit the star closer.^[6]