Issue |
A&A
Volume 682, February 2024
|
|
---|---|---|
Article Number | A17 | |
Number of page(s) | 9 | |
Section | Interstellar and circumstellar matter | |
DOI | https://doi.org/10.1051/0004-6361/202348189 | |
Published online | 29 January 2024 |
Seven-year periodic variations in the methanol maser line displayed by the massive protostar IRAS 20216+4104★
1
Institute of Astronomy, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University,
Grudziadzka 5,
87-100
Torun,
Poland
e-mail: msz@astro.umk.pl
2
South African Radio Astronomy Observatory,
2 Fir Street,
Observatory
7925,
South Africa
3
INAF – Osservatorio Astronomico di Capodimonte,
salita Moiariello 16,
80131
Napoli,
Italy
4
INAF – Osservatorio Astrofisico di Arcetri,
Largo E. Fermi 5,
50125
Firenze,
Italy
Received:
7
October
2023
Accepted:
10
November
2023
Aims. We report the discovery and analysis of a periodic methanol maser in the massive protostar IRAS 20216+4104.
Methods. To obtain the light curve, we used the 6.7 GHz methanol maser spectra collected between 2000–2003 and 2009–2023 with the Hartebeesthoek and Torun radio telescopes, as well as spectra from the literature reported prior to 1992.
Results. The velocity-integrated flux density shows sinusoidal-like variations with a period of 6.9±0.03 yr. All but one of the features show periodic changes with a relative amplitude of 2 up to >89. A slightly variable feature displays a moderate anti-correlation between the flux density and the other significantly variable features. The maser emission appears to follow the continuum emission of the red-shifted outflow cavity. A maximum emission of 3.4 and 4.6 µm precedes the maser peak by 15% of the period and the (infrared) IR light centroids show time-dependent displacement. The periodic behaviour of the maser and IR emission is likely due to the eclipsing effect from a wobbling inner disk.
Key words: ISM: molecules / ISM: individual objects: IRAS 20216+4104 / stars: formation / masers
The reduced spectra are available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/682/A17
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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