Latitude-dependent Atmospheric Waves and Long-period Modulations in Luhman 16 B from the Longest Light Curve of an Extrasolar World
In this work, we present the longest photometric monitoring of up to 1200 hr of the strongly variable brown dwarf binaries Luhman 16 AB and provide evidence of ±5% variability on a timescale of several to hundreds of hours for this object. We show that short-period rotational modulation around 5 hr...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad2c84 |
| _version_ | 1797201841982799872 |
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| author | Nguyen Fuda Dániel Apai Domenico Nardiello Xianyu Tan Theodora Karalidi Luigi Rolly Bedin |
| author_facet | Nguyen Fuda Dániel Apai Domenico Nardiello Xianyu Tan Theodora Karalidi Luigi Rolly Bedin |
| author_sort | Nguyen Fuda |
| collection | DOAJ |
| description | In this work, we present the longest photometric monitoring of up to 1200 hr of the strongly variable brown dwarf binaries Luhman 16 AB and provide evidence of ±5% variability on a timescale of several to hundreds of hours for this object. We show that short-period rotational modulation around 5 hr ( k = 1 wavenumber) and 2.5 hr ( k = 2 wavenumber) dominate the variability under 10 hr, where the planetary-scale wave model composed of k = 1 and k = 2 waves provides good fits to both the periodograms and light curve. In particular, models consisting of three to four sine waves could explain the variability of the light-curve durations up to 100 hr. We show that the relative range of the k = 2 periods is narrower compared to the k = 1 periods. Using simple models of zonal banding in solar system giants, we suggest that the difference in period range arises from the difference in wind-speed distribution at low and mid-to-high latitudes in the atmosphere. Last, we show that Luhman 16 AB also exhibits long-period ±5% variability, with periods ranging from 15 hr up to 100 hr over the longest monitoring of this object. Our results for the k = 1 and k = 2 waves and long-period evolution are consistent with previous 3D atmosphere simulations, demonstrating that both latitude-dependent waves and slow-varying atmospheric features are potentially present in Luhman 16 AB atmospheres and are a significant contribution to the light-curve modulation over hundreds of rotations. |
| first_indexed | 2024-04-24T07:53:58Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-04-24T07:53:58Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-fdfdc3feb7994b9496b358fec62cf5522024-04-18T08:55:52ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-01965218210.3847/1538-4357/ad2c84Latitude-dependent Atmospheric Waves and Long-period Modulations in Luhman 16 B from the Longest Light Curve of an Extrasolar WorldNguyen Fuda0https://orcid.org/0000-0002-6372-8395Dániel Apai1https://orcid.org/0000-0003-3714-5855Domenico Nardiello2https://orcid.org/0000-0003-1149-3659Xianyu Tan3https://orcid.org/0000-0003-2278-6932Theodora Karalidi4https://orcid.org/0000-0001-7356-6652Luigi Rolly Bedin5https://orcid.org/0000-0003-4080-6466Lunar and Planetary Laboratory, University of Arizona , 1640 E. University Boulevard, Tucson, AZ 85721, USA ; fuda@lpl.arizona.eduLunar and Planetary Laboratory, University of Arizona , 1640 E. University Boulevard, Tucson, AZ 85721, USA ; fuda@lpl.arizona.edu; Steward Observatory, The University of Arizona , 933 N. Cherry Avenue, Tucson, AZ 85721, USAINAF-Osservatorio Astronomico di Padova , Vicolo dell’Osservatorio 5, I-35122 Padova, ItalyTsung-Dao Lee Institute, Shanghai Jiao Tong University , 520 Shengrong Road, Shanghai 201210, People's Republic of China; School of Physics and Astronomy, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, People's Republic of ChinaDepartment of Physics, University of Central Florida , 4111 Libra Dr, Orlando, FL 32816, USAINAF-Osservatorio Astronomico di Padova , Vicolo dell’Osservatorio 5, I-35122 Padova, ItalyIn this work, we present the longest photometric monitoring of up to 1200 hr of the strongly variable brown dwarf binaries Luhman 16 AB and provide evidence of ±5% variability on a timescale of several to hundreds of hours for this object. We show that short-period rotational modulation around 5 hr ( k = 1 wavenumber) and 2.5 hr ( k = 2 wavenumber) dominate the variability under 10 hr, where the planetary-scale wave model composed of k = 1 and k = 2 waves provides good fits to both the periodograms and light curve. In particular, models consisting of three to four sine waves could explain the variability of the light-curve durations up to 100 hr. We show that the relative range of the k = 2 periods is narrower compared to the k = 1 periods. Using simple models of zonal banding in solar system giants, we suggest that the difference in period range arises from the difference in wind-speed distribution at low and mid-to-high latitudes in the atmosphere. Last, we show that Luhman 16 AB also exhibits long-period ±5% variability, with periods ranging from 15 hr up to 100 hr over the longest monitoring of this object. Our results for the k = 1 and k = 2 waves and long-period evolution are consistent with previous 3D atmosphere simulations, demonstrating that both latitude-dependent waves and slow-varying atmospheric features are potentially present in Luhman 16 AB atmospheres and are a significant contribution to the light-curve modulation over hundreds of rotations.https://doi.org/10.3847/1538-4357/ad2c84Brown dwarfsExoplanet atmospheresBroad band photometryAtmospheric circulation |
| spellingShingle | Nguyen Fuda Dániel Apai Domenico Nardiello Xianyu Tan Theodora Karalidi Luigi Rolly Bedin Latitude-dependent Atmospheric Waves and Long-period Modulations in Luhman 16 B from the Longest Light Curve of an Extrasolar World The Astrophysical Journal Brown dwarfs Exoplanet atmospheres Broad band photometry Atmospheric circulation |
| title | Latitude-dependent Atmospheric Waves and Long-period Modulations in Luhman 16 B from the Longest Light Curve of an Extrasolar World |
| title_full | Latitude-dependent Atmospheric Waves and Long-period Modulations in Luhman 16 B from the Longest Light Curve of an Extrasolar World |
| title_fullStr | Latitude-dependent Atmospheric Waves and Long-period Modulations in Luhman 16 B from the Longest Light Curve of an Extrasolar World |
| title_full_unstemmed | Latitude-dependent Atmospheric Waves and Long-period Modulations in Luhman 16 B from the Longest Light Curve of an Extrasolar World |
| title_short | Latitude-dependent Atmospheric Waves and Long-period Modulations in Luhman 16 B from the Longest Light Curve of an Extrasolar World |
| title_sort | latitude dependent atmospheric waves and long period modulations in luhman 16 b from the longest light curve of an extrasolar world |
| topic | Brown dwarfs Exoplanet atmospheres Broad band photometry Atmospheric circulation |
| url | https://doi.org/10.3847/1538-4357/ad2c84 |
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