ASASSN-21js: A multi-year transit of a ringed disc
arXiv:2408.06744 · doi:10.1051/0004-6361/202450288
Abstract
The early-type star ASASSN-21js started to fade in 2021, as was detected by the All Sky Automated Survey for Supernovae, undergoing a multi-year eclipse that is still underway. We interpret this event as being due to a structured disc of material transiting in front of the star. The disc is in orbit around a substellar object with the mass and luminosity of a brown dwarf or smaller. We want to determine the expected duration and ending date of the eclipse. We modelled a tilted and inclined azimuthally symmetric ring system around an unseen companion and calculated the resulting time-varying light curve as the object transited in front of the star. We made an initial estimate of the ring parameters and used these as inputs to an MCMC algorithm to determine the geometric properties of the rings with associated uncertainties. The model most consistent with the light curve to date is a two-ring system at high inclination with respect to the line of sight that has a semi-major axis of 71.6 stellar radii. With an estimate of the stellar radius, the transverse velocity is around 0.7 km/s, which if bound to the star is an orbit with a semi-major axis of around 13000 au, placing it in the Oort cloud of the parent star. The transit is ongoing and will finish around MJD 61526 (May 1 2027). We encourage the community to continue observing this object in order to understand its properties.
9 pages, 4 figures, 6 tables, repository for paper at: https://github.com/mkenworthy/ASASSN-21js
References in corpus (27)
- emcee: The MCMC Hammer
- The Gaia mission
- Gaia Data Release 3: Summary of the content and survey properties
- A new extensive library of PHOENIX stellar atmospheres and synthetic spectra
- The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
- The VizieR database of Astronomical Catalogues
- GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy
- Theoretical isochrones in several photometric systems I. Johnson-Cousins-Glass, HST/WFPC2, HST/NICMOS, Washington, and ESO Imaging Survey filter sets
- The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
- Towards Better Age Estimates for Stellar Populations: The Y^2 Isochrones for Solar Mixture
- The YY Isochrones for alpha-element Enhanced Mixtures
- A ring system detected around the Centaur (10199) Chariklo
- The Y^2 Stellar Evolutionary Tracks
- Stellar Limb-Darkening Coefficients for CoRot and Kepler
- Parallel Implementation of the PHOENIX Generalized Stellar Atmosphere Program
- The VST Photometric Halpha Survey of the Southern Galactic Plane and Bulge (VPHAS+)
- Planetary Construction Zones in Occultation: Discovery of an Extrasolar Ring System Transiting a Young Sun-like Star and Future Prospects for Detecting Eclipses by Circumsecondary and Circumplanetary Disks
- Modeling giant extrasolar ring systems in eclipse and the case of J1407b: sculpting by exomoons?
- The Carlsberg Meridian Telescope CCD Drift Scan Survey
- MOBSTER - II. Identification of rotationally variable A stars observed with \emph{TESS} in Sectors 1 to 4
- The Second Discovery from the COol Companions ON Ultrawide orbiTS (COCONUTS) Program: A Cold Wide-Orbit Exoplanet around a Young Field M Dwarf at 10.9 pc
- An Extreme Analogue of Aurigae: An M-giant Eclipsed Every 69 Years by a Large Opaque Disk Surrounding a Small Hot Source
- Discovery of an unusual bright eclipsing binary with the longest known period: TYC 2505-672-1 / MASTER OT J095310.04+335352.8
- Periodic Eclipses of the Young Star PDS 110 Discovered with WASP and KELT Photometry
- VVV-WIT-08: the giant star that blinked
- The most variable VVV sources: eruptive protostars, dipping giants in the Nuclear Disc and others
- SkyMapper Southern Survey: Data Release 4