The discovery of new warm debris disks around F-type stars

Abstract

We report the discovery of four rare debris disks with warm excesses around F-stars, significantly increasing the number of such systems known in the solar neighborhood. Three of the disks are consistent with the predictions of steady state planetesimal disk evolution models. The oldest source, HD 169666, displays a dust fractional luminosity too high to be in steady state and we suggest that this system recently underwent a transient event of dust production. In addition, two spectra of this star separated by ~three years show silicate emission features, indicative of submicron- to micron-sized grains. We argue that such small grains would be rapidly depleted and their presence in both spectra suggests that the production of small dust is continuous over at least on few years timescale. We predict that systems showing variable mid-infrared spectra, if exist, will provide valuable help in distinguishing the possible scenarios proposed for dust replenishment.

Accepted for publication in ApJ Letters, 13 pages, 2 figures, 2 tables

References in corpus (15)

• The Geneva-Copenhagen Survey of the Solar neighbourhood II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk
• Transience of hot dust around sun-like stars
• Nearby debris disk systems with high fractional luminosity reconsidered
• Formation and Evolution of Planetary Systems (FEPS): Properties of Debris Dust around Solar-type Stars
• Binarity as a key factor in protoplanetary disk evolution: Spitzer disk census of the eta Chamaeleontis cluster
• Evolution of Mid-IR Excess Around Sun-like Stars: Constraints on Models of Terrestrial Planet Formation
• Warm dust in the terrestrial planet zone of a sun-like Pleiad: collisions between planetary embryos?
• Circumstellar Dust Created by Terrestrial Planet Formation in HD 113766
• Medium-separation binaries do not affect the first steps of planet formation
• IRS Spectra of Solar-Type Stars: \break A Search for Asteroid Belt Analogs
• Debris Disks in NGC 2547
• A Spitzer Study of Debris Disks In The Young Nearby Cluster NGC 2232: Icy Planets Are Common Around ~ 1.5--3 Solar-Mass Stars
• The nature of mid-infrared excesses from hot dust around Sun-like stars
• The X-ray luminosity of solar-mass stars in the intermediate age open cluster NGC 752
• Terrestrial Zone Debris Disk Candidates in h and chi Persei

Cited by in corpus (12)

• A Sensitive Identification of Warm Debris Disks in the Solar Neighborhood Through Precise Calibration of Saturated WISE Photometry
• A Direct Imaging Survey of Spitzer detected debris disks: Occurrence of giant planets in dusty systems
• Planet populations inferred from debris discs: insights from 178 debris systems in the ISPY, LEECH and LIStEN planet-hunting surveys
• The HIP 79977 debris disk in polarized light
• Does warm debris dust stem from asteroid belts?
• Warm Dust around Cool Stars: Field M Dwarfs with WISE 12 or 22 Micron Excess Emission
• Rocky Planet Formation: Quick and Neat
• Probing the Terrestrial Regions of Planetary Systems: Warm Debris Disks with Emission Features
• What Sets the Radial Locations of Warm Debris Disks?
• Warm Dusty Debris Disks and Distant Companion Stars: V488 Per and 2M1337
• V488 Per revisited: no strong mid-infrared emission features and no evidence for stellar/sub-stellar companions
• Three new late-type stellar companions to very dusty WISE debris disks identified with VLT/SPHERE imaging