A near-infrared interferometric survey of debris-disk stars. VI. Extending the exozodiacal light survey with CHARA/JouFLU

Abstract

We report the results of high-angular-resolution observations that search for exozodiacal light in a sample of main sequence stars and sub-giants. Using the "jouvence" of the fiber linked unit for optical recombination (JouFLU) at the center for high angular resolution astronomy (CHARA) telescope array, we have observed a total of 44 stars. Out of the 44 stars, 33 are new stars added to the initial, previously published survey of 42 stars performed at CHARA with the fiber linked unit for optical recombiation (FLUOR). Since the start of the survey extension, we have detected a K-band circumstellar excess for six new stars at the ~ 1\% level or higher, four of which are known or candidate binaries, and two for which the excess could be attributed to exozodiacal dust. We have also performed follow-up observations of 11 of the stars observed in the previously published survey and found generally consistent results. We do however detect a significantly larger excess on three of these follow-up targets: Altair, $\upsilon$ And and $\kappa$ CrB. Interestingly, the last two are known exoplanet host stars. We perform a statistical analysis of the JouFLU and FLUOR samples combined, which yields an overall exozodi detection rate of $21.7_{-4.1}^{+5.7}\%$. We also find that the K-band excess in FGK-type stars correlates with the existence of an outer reservoir of cold ($\lesssim 100$K) dust at the $99\%$ confidence level, while the same cannot be said for A-type stars.

Accepted for publication in Astronomy & Astrophysics. 18 pages, 20 figures

References in corpus (7)

• Imaging the Surface of Altair
• No Sun-like dynamo on the active star $\zeta$ Andromedae from starspot asymmetry
• Retired A Stars and Their Companions II: Jovian planets orbiting kappa Coronae Borealis and HD167042
• A near-infrared interferometric survey of debris disk stars. I. Probing the hot dust content around epsilon Eridani and tau Ceti with CHARA/FLUOR
• A near-infrared interferometric survey of debris-disc stars. V. PIONIER search for variability
• CHARA/MIRC observations of two M supergiants in Perseus OB1: temperature, Bayesian modeling, and compressed sensing imaging
• Constraints on the structure of hot exozodiacal dust belts

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• A near-infrared interferometric survey of debris-disk stars. VII. The hot/warm dust connection
• First L band detection of hot exozodiacal dust with VLTI/MATISSE
• Polarization measurements of the polluted white dwarf G29-38