Transiting exocomets detected in broadband light by TESS in the β Pictoris system

Abstract

Aims. We search for signs of falling evaporating bodies (FEBs, also known as exocomets) in photometric time series obtained for β Pictoris after fitting and removing its δ Scuti-type pulsation frequencies.Methods. Using photometric data obtained by the TESS satellite we determined the pulsational properties of the exoplanet host star β Pictoris through frequency analysis. We then pre-whitened the 54 identified δ Scuti p-modes and investigated the residual photometric time series for the presence of FEBs. Results. We identify three distinct dipping events in the light curve of β Pictoris over a 105-day period. These dips have depths from 0.5 to 2 millimagnitudes and durations of up to 2 days for the largest dip. These dips are asymmetric in nature and are consistent with a model of an evaporating comet with an extended tail crossing the disc of the star. Conclusions. We present the first broadband detections of exocomets crossing the disc of β Pictoris, complementing the predictions made 20 years earlier by Lecavelier Des . No periodic transits are seen in this time series. These observations confirm the spectroscopic detection of exocomets in calcium H and K lines that have been seen in high resolution spectroscopy.

Peering into the formation history of β Pictoris b with VLTI/GRAVITY long-baseline interferometry

“…However, a moderate eccentricity would fit nicely in the dynamics of the system. An e ≈ 0.15 is consistent with the picture of an eccentric β Pic b launching small bodies towards the star, causing spectroscopic and transiting signatures of exocomets in observations of the star (Thébault & Beust 2001;Zieba et al 2019). An interesting question is how such a massive planet acquired a significant eccentricity.…”

The Consequences of COVID-19 Toward Human Growth: The Role of Traumatic Event and Coping Strategies Among Indonesian Sample

“…This study found that participants were exposed to trauma from the emergence of the COVID-19 outbreak in Indonesia. Inconsistent with some other studies (Siqveland et al, 2015;Zieba et al, 2019), trauma condition scores do not significantly affect the stress-related growth experienced by individuals. This is because the emergence of growth requires gradual cognitive processes and perceived traumatic experiences.…”

The Composition, Excitation, and Physical State of Atomic Gas in the Debris Disk Surrounding 51 Oph∗

“…In the 51 Oph system, solid cometary material with a similar composition could have been converted to gaseous form from collisions or during close approaches toward the star. Such an outlook is consistent with the observations of transient absorption lines associated with falling evaporating bodies (FEBs) detected for 51 Oph and other stars with circumstellar disks (Vidal-Madjar et al 1994Beust et al 1998Beust et al , 2001Karmann et al 2001Karmann et al , 2003Thébault & Beust 2001 ;Roberge et al 2002 ;Beust & Valiron 2007 ;Welsh & Montgomery 2013 ;Kiefer et al 2014Kiefer et al , 2019Eiroa et al 2016 ;Vidal-Madjar et al 2017 ;Zieba et al 2019).…”