Title: Mid-infrared time-domain study of recent dust production events in the extreme debris disc of TYC 4209-1322-1
ABSTRACT
Extreme debris discs are characterized by unusually strong mid-infrared excess emission, which often proves to be variable. The warm dust in these discs is of transient nature and is likely related to a recent giant collision occurring close to the star in the terrestrial region. Here we present the results of a 877 d long, gap-free photometric monitoring performed by the Spitzer Space Telescope of the recently discovered extreme debris disc around TYC 4209-1322-1. By combining these observations with other time-domain optical and mid-infrared data, we explore the disc variability of the last four decades with particular emphasis on the last 12 yr. During the latter interval the disc showed substantial changes, the most significant was the brightening and subsequent fading between 2014 and 2018 as outlined in WISE data. The Spitzer light curves outline the fading phase and a subsequent new brightening of the disc after 2018, revealing an additional flux modulation with a period of ∼39 d on top of the long-term trend. We found that all these variations can be interpreted as the outcome of a giant collision that happened at an orbital radius of ∼0.3 au sometime in 2014. Our analysis implies that a collision on a similar scale could have taken place around 2010, too. The fact that the disc was already peculiarly dust rich 40 yr ago, as implied by IRAS data, suggests that these dust production events belong to a chain of large impacts triggered by an earlier even more catastrophic collision.
Swan, Andrew; Kenyon, Scott J; Farihi, Jay; Dennihy, Erik; Gänsicke, Boris T; Hermes, J J; Melis, Carl; von Hippel, Ted(
, Monthly Notices of the Royal Astronomical Society)
null
(Ed.)
ABSTRACT WD 0145+234 is a white dwarf that is accreting metals from a circumstellar disc of planetary material. It has exhibited a substantial and sustained increase in 3–5 $\mu$m flux since 2018. Follow-up Spitzer photometry reveals that emission from the disc had begun to decrease by late 2019. Stochastic brightening events superimposed on the decline in brightness suggest the liberation of dust during collisional evolution of the circumstellar solids. A simple model is used to show that the observations are indeed consistent with ongoing collisions. Rare emission lines from circumstellar gas have been detected at this system, supporting the emerging picture of white dwarf debris discs as sites of collisional gas and dust production.
Farnocchia, Davide; Seligman, Darryl Z.; Granvik, Mikael; Hainaut, Olivier; Meech, Karen J.; Micheli, Marco; Weryk, Robert; Chesley, Steven R.; Christensen, Eric J.; Koschny, Detlef; et al(
, The Planetary Science Journal)
Abstract
We report a statistically significant detection of nongravitational acceleration on the subkilometer near-Earth asteroid (523599) 2003 RM. Due to its orbit, 2003 RM experiences favorable observing apparitions every 5 yr. Thus, since its discovery, 2003 RM has been extensively tracked with ground-based optical facilities in 2003, 2008, 2013, and 2018. We find that the observed plane-of-sky positions cannot be explained with a purely gravity-driven trajectory. Including a transverse nongravitational acceleration allows us to match all observational data, but its magnitude is inconsistent with perturbations typical of asteroids such as the Yarkovsky effect or solar radiation pressure. After ruling out that the orbital deviations are due to a close approach or collision with another asteroid, we hypothesize that this anomalous acceleration is caused by unseen cometary outgassing. A detailed search for evidence of cometary activity with archival and deep observations from the Panoramic Survey Telescope and Rapid Response System and the Very Large Telescope does not reveal any detectable dust production. However, the best-fitting H2O sublimation model allows for brightening due to activity consistent with the scatter of the data. We estimate the production rate required for H2O outgassing to power the acceleration and find that, assuming a diameter of 300 m, 2003 RM would require Q(H2O) ∼ 1023molec s−1at perihelion. We investigate the recent dynamical history of 2003 RM and find that the object most likely originated in the mid-to-outer main belt (∼86% probability) as opposed to from the Jupiter-family comet region (∼11% probability). Further observations, especially in the infrared, could shed light on the nature of this anomalous acceleration.
Gaidos, Eric; Mann, Andrew W; Rojas-Ayala, Bárbara; Feiden, Gregory A; Wood, Mackenna L; Narayanan, Suchitra; Ansdell, Megan; Jacobs, Tom; LaCourse, Daryll(
, Monthly Notices of the Royal Astronomical Society)
ABSTRACT Studies of T Tauri discs inform planet formation theory; observations of variability due to occultation by circumstellar dust are a useful probe of unresolved, planet-forming inner discs, especially around faint M dwarf stars. We report observations of 2M0632, an M dwarf member of the Carina young moving group that was observed by Transiting Exoplanet Survey Satellite over two 1-yr intervals. The combined light curve contains >300 dimming events, each lasting a few hours, and as deep as 40 per cent (0.55 magnitudes). These stochastic events are correlated with a distinct, stable 1.86-d periodic signal that could be stellar rotation. Concurrent ground-based, multiband photometry show reddening consistent with interstellar medium-like dust. The star’s excess emission in the infrared and emission lines in optical and infrared spectra reveal a T Tauri-like accretion disc around the star. We confirm membership of 2M0632 in the Carina group by a Bayesian analysis of its Galactic space motion and position. We combine stellar evolution models with Gaia photometry and constraints on Teff, luminosity, and the absence of detectable lithium in the photosphere to constrain the age of the group and 2M0632 to 40–60 Myr, consistent with earlier estimates. 2M0632 joins a handful of long-lived discs which challenge the canon that disc lifetimes are ≲10 Myr. All known examples surround M dwarfs, suggesting that lower X-ray/ultraviolet irradiation and slower photoevaporation by these stars can dramatically affect disc evolution. The multiplanet systems spawned by long-lived discs probably experienced significant orbital damping and migration into close-in, resonant orbits, and perhaps represented by the TRAPPIST-1 system.
Panagiotou, Christos; De, Kishalay; Masterson, Megan; Kara, Erin; Calzadilla, Michael; Eilers, Anna-Christina; Frostig, Danielle; Karambelkar, Viraj; Kasliwal, Mansi; Lourie, Nathan; et al(
, The Astrophysical Journal Letters)
Abstract
While the vast majority of tidal disruption events (TDEs) have been identified by wide-field sky surveys in the optical and X-ray bands, recent studies indicate that a considerable fraction of TDEs may be dust obscured and thus preferentially detected in the infrared (IR) wave bands. In this Letter, we present the discovery of a luminous mid-IR nuclear flare (termed WTP14adbjsh), identified in a systematic transient search of archival images from the NEOWISE mid-IR survey. The source reached a peak luminosity ofL≃ 1043erg s−1at 4.6μm in 2015 before fading in the IR with a TDE-likeF∝t−5/3decline, radiating a total of more than 3 × 1051erg in the last 7 yr. The transient event took place in the nearby galaxy NGC 7392, at a distance of around 42 Mpc; yet, no optical or X-ray flare is detected. We interpret the transient as the nearest TDE candidate detected in the last decade, which was missed at other wavelengths due to dust obscuration, hinting at the existence of TDEs that have been historically overlooked. Unlike most previously detected TDEs, the transient was discovered in a star-forming galaxy, corroborating earlier suggestions that dust obscuration suppresses significantly the detection of TDEs in these environments. Our results demonstrate that the study of IR-detected TDEs is critical in order to obtain a complete understanding of the physics of TDEs and to conclude whether TDEs occur preferentially in a particular class of galaxies.
Matsuura, Mikako; Wesson, Roger; Arendt, Richard G.; Dwek, Eli; De Buizer, James M.; Danziger, John; Bouchet, Patrice; Barlow, M. J.; Cigan, Phil; Gomez, Haley L.; et al(
, Monthly Notices of the Royal Astronomical Society)
ABSTRACT
At a distance of 50 kpc, Supernova 1987A is an ideal target to study how a young supernova (SN) evolves in time. Its equatorial ring, filled with material expelled from the progenitor star about 20 000 yr ago, has been engulfed with SN blast waves. Shocks heat dust grains in the ring, emitting their energy at mid-infrared (IR) wavelengths We present ground-based 10–18 μm monitoring of the ring of SN 1987A from day 6067 to 12814 at a resolution of 0.5 arcsec, together with SOFIA photometry at 10–30 μm. The IR images in the 2000’s (day 6067–7242) showed that the shocks first began brightening the east side of the ring. Later, our mid-IR images from 2017 to 2022 (day 10952–12714) show that dust emission is now fading in the east, while it has brightened on the west side of the ring. Because dust grains are heated in the shocked plasma, which can emit X-rays, the IR and X-ray brightness ratio represent shock diagnostics. Until 2007 the IR to X-ray brightness ratio remained constant over time, and during this time shocks seemed to be largely influencing the east side of the ring. However, since then, the IR to X-ray ratio has been declining, due to increased X-ray brightness. Whether the declining IR brightness is because of dust grains being destroyed or being cooled in the post-shock regions will require more detailed modelling.
Moór, Attila, Ábrahám, Péter, Kóspál, Ágnes, Su, Kate Y. L., Rieke, George H., Vida, Krisztián, Cataldi, Gianni, Bódi, Attila, Bognár, Zsófia, Cseh, Borbála, Csörnyei, Géza, Egei, Nóra, Farkas, Anikó, Hanyecz, Ottó, Ignácz, Bernadett, Kalup, Csilla, Könyves-Tóth, Réka, Kriskovics, Levente, Mészáros, László, Pál, András, Ordasi, András, Sárneczky, Krisztián, Seli, Bálint, Sódor, Ádám, Szakáts, Róbert, Vinkó, József, and Zsidi, Gabriella. Mid-infrared time-domain study of recent dust production events in the extreme debris disc of TYC 4209-1322-1. Monthly Notices of the Royal Astronomical Society 516.4 Web. doi:10.1093/mnras/stac2595.
Moór, Attila, Ábrahám, Péter, Kóspál, Ágnes, Su, Kate Y. L., Rieke, George H., Vida, Krisztián, Cataldi, Gianni, Bódi, Attila, Bognár, Zsófia, Cseh, Borbála, Csörnyei, Géza, Egei, Nóra, Farkas, Anikó, Hanyecz, Ottó, Ignácz, Bernadett, Kalup, Csilla, Könyves-Tóth, Réka, Kriskovics, Levente, Mészáros, László, Pál, András, Ordasi, András, Sárneczky, Krisztián, Seli, Bálint, Sódor, Ádám, Szakáts, Róbert, Vinkó, József, and Zsidi, Gabriella.
"Mid-infrared time-domain study of recent dust production events in the extreme debris disc of TYC 4209-1322-1". Monthly Notices of the Royal Astronomical Society 516 (4). Country unknown/Code not available: Oxford University Press. https://doi.org/10.1093/mnras/stac2595.https://par.nsf.gov/biblio/10372365.
@article{osti_10372365,
place = {Country unknown/Code not available},
title = {Mid-infrared time-domain study of recent dust production events in the extreme debris disc of TYC 4209-1322-1},
url = {https://par.nsf.gov/biblio/10372365},
DOI = {10.1093/mnras/stac2595},
abstractNote = {ABSTRACT Extreme debris discs are characterized by unusually strong mid-infrared excess emission, which often proves to be variable. The warm dust in these discs is of transient nature and is likely related to a recent giant collision occurring close to the star in the terrestrial region. Here we present the results of a 877 d long, gap-free photometric monitoring performed by the Spitzer Space Telescope of the recently discovered extreme debris disc around TYC 4209-1322-1. By combining these observations with other time-domain optical and mid-infrared data, we explore the disc variability of the last four decades with particular emphasis on the last 12 yr. During the latter interval the disc showed substantial changes, the most significant was the brightening and subsequent fading between 2014 and 2018 as outlined in WISE data. The Spitzer light curves outline the fading phase and a subsequent new brightening of the disc after 2018, revealing an additional flux modulation with a period of ∼39 d on top of the long-term trend. We found that all these variations can be interpreted as the outcome of a giant collision that happened at an orbital radius of ∼0.3 au sometime in 2014. Our analysis implies that a collision on a similar scale could have taken place around 2010, too. The fact that the disc was already peculiarly dust rich 40 yr ago, as implied by IRAS data, suggests that these dust production events belong to a chain of large impacts triggered by an earlier even more catastrophic collision.},
journal = {Monthly Notices of the Royal Astronomical Society},
volume = {516},
number = {4},
publisher = {Oxford University Press},
author = {Moór, Attila and Ábrahám, Péter and Kóspál, Ágnes and Su, Kate Y. L. and Rieke, George H. and Vida, Krisztián and Cataldi, Gianni and Bódi, Attila and Bognár, Zsófia and Cseh, Borbála and Csörnyei, Géza and Egei, Nóra and Farkas, Anikó and Hanyecz, Ottó and Ignácz, Bernadett and Kalup, Csilla and Könyves-Tóth, Réka and Kriskovics, Levente and Mészáros, László and Pál, András and Ordasi, András and Sárneczky, Krisztián and Seli, Bálint and Sódor, Ádám and Szakáts, Róbert and Vinkó, József and Zsidi, Gabriella},
}
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