Publication Date:
2020-09-09
Description:
For the first time, we observed the emission of hot exozodiacal dust in L band. We used the new instrument MATISSE at the Very Large Telescope Interferometer to detect the hot dust around κ Tuc with a significance of 3σ to 6σ at wavelengths between 3.37 and $3.85, {mu {
m m}}$ and a dust-to-star flux ratio of 5 to $7{{{
m per cent}}}$. We modelled the spectral energy distribution based on the new L band data alone and in combination with H band data published previously. In all cases we find $0.58, {mu {
m m}}$ grains of amorphous carbon to fit the κ Tuc observations the best, however, also nanometre or micrometre grains and other carbons or silicates reproduce the observations well. Since the H band data revealed a temporal variability, while our Lband data were taken at a different epoch, we combine them in different ways. Depending on the approach, the best fits are obtained for a narrow dust ring at a stellar distance in the 0.1–029 au range and thus with a temperature between 940 and $1430, {
m K}$. Within the 1σ uncertainty dust location and temperature are confined to $0.032{!-!}1.18, {
m au}$ and $600{!-!}2000, {
m K}$.
Print ISSN:
1745-3925
Electronic ISSN:
1745-3933
Topics:
Physics
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