Maps of evolving cloud structures in luhman 16AB from hst time-resolved spectroscopy

Theodora Karalidi, Daniel Apai, Mark S. Marley, Esther Buenzli

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

WISE J104915.57-531906.1 is the nearest brown dwarf binary to our solar system, consisting of two brown dwarfs in the L/T transition: Luhman 16A and B. In this paper, we present the first map of Luhman 16A, and maps of Luhman 16B for two epochs. Our maps were created by applying Aeolus, a Markov-Chain Monte Carlo code that maps the top-of-the-atmosphere (TOA) structure of brown dwarf and other ultracool atmospheres, to light curves of Luhman 16A and B using the Hubble Space Telescope's G141 and G102 grisms. Aeolus retrieved three or four spots in the TOA of Luhman 16A and B, with a surface coverage of 19%-32% (depending on an assumed rotational period of 5 hr or 8 hr) or 21%-38.5% (depending on the observational epoch), respectively. The brightness temperature of the spots of the best-fit models was ∼200 K hotter than the background TOA. We compared our Luhman 16B map with the only previously published map. Interestingly, our map contained a large TOA spot that was cooler (ΔT ∼ 51 K) than the background, which lay at low latitudes, in agreement with the previous Luhman 16B map. Finally, we report the detection of a feature reappearing in Luhman 16B light curves that are separated by tens of hundreds of rotations from each other. We speculate that this feature is related to TOA structures of Luhman 16B.

Original languageEnglish (US)
Article number90
JournalAstrophysical Journal
Volume825
Issue number2
DOIs
StatePublished - Jul 10 2016

Fingerprint

spectroscopy
atmospheres
atmosphere
light curve
time measurement
Wide-field Infrared Survey Explorer
Markov chains
brightness temperature
Markov chain
coolers
tropical regions
Hubble Space Telescope
solar system

Keywords

  • methods: statistical
  • stars: individual (WISE J104915.57-531906.1)
  • techniques: photometric

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Maps of evolving cloud structures in luhman 16AB from hst time-resolved spectroscopy. / Karalidi, Theodora; Apai, Daniel; Marley, Mark S.; Buenzli, Esther.

In: Astrophysical Journal, Vol. 825, No. 2, 90, 10.07.2016.

Research output: Contribution to journalArticle

Karalidi, Theodora ; Apai, Daniel ; Marley, Mark S. ; Buenzli, Esther. / Maps of evolving cloud structures in luhman 16AB from hst time-resolved spectroscopy. In: Astrophysical Journal. 2016 ; Vol. 825, No. 2.
@article{4cc94fff5cf64c8f83edf40a253a5a94,
title = "Maps of evolving cloud structures in luhman 16AB from hst time-resolved spectroscopy",
abstract = "WISE J104915.57-531906.1 is the nearest brown dwarf binary to our solar system, consisting of two brown dwarfs in the L/T transition: Luhman 16A and B. In this paper, we present the first map of Luhman 16A, and maps of Luhman 16B for two epochs. Our maps were created by applying Aeolus, a Markov-Chain Monte Carlo code that maps the top-of-the-atmosphere (TOA) structure of brown dwarf and other ultracool atmospheres, to light curves of Luhman 16A and B using the Hubble Space Telescope's G141 and G102 grisms. Aeolus retrieved three or four spots in the TOA of Luhman 16A and B, with a surface coverage of 19{\%}-32{\%} (depending on an assumed rotational period of 5 hr or 8 hr) or 21{\%}-38.5{\%} (depending on the observational epoch), respectively. The brightness temperature of the spots of the best-fit models was ∼200 K hotter than the background TOA. We compared our Luhman 16B map with the only previously published map. Interestingly, our map contained a large TOA spot that was cooler (ΔT ∼ 51 K) than the background, which lay at low latitudes, in agreement with the previous Luhman 16B map. Finally, we report the detection of a feature reappearing in Luhman 16B light curves that are separated by tens of hundreds of rotations from each other. We speculate that this feature is related to TOA structures of Luhman 16B.",
keywords = "methods: statistical, stars: individual (WISE J104915.57-531906.1), techniques: photometric",
author = "Theodora Karalidi and Daniel Apai and Marley, {Mark S.} and Esther Buenzli",
year = "2016",
month = "7",
day = "10",
doi = "10.3847/0004-637X/825/2/90",
language = "English (US)",
volume = "825",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2",

}

TY - JOUR

T1 - Maps of evolving cloud structures in luhman 16AB from hst time-resolved spectroscopy

AU - Karalidi, Theodora

AU - Apai, Daniel

AU - Marley, Mark S.

AU - Buenzli, Esther

PY - 2016/7/10

Y1 - 2016/7/10

N2 - WISE J104915.57-531906.1 is the nearest brown dwarf binary to our solar system, consisting of two brown dwarfs in the L/T transition: Luhman 16A and B. In this paper, we present the first map of Luhman 16A, and maps of Luhman 16B for two epochs. Our maps were created by applying Aeolus, a Markov-Chain Monte Carlo code that maps the top-of-the-atmosphere (TOA) structure of brown dwarf and other ultracool atmospheres, to light curves of Luhman 16A and B using the Hubble Space Telescope's G141 and G102 grisms. Aeolus retrieved three or four spots in the TOA of Luhman 16A and B, with a surface coverage of 19%-32% (depending on an assumed rotational period of 5 hr or 8 hr) or 21%-38.5% (depending on the observational epoch), respectively. The brightness temperature of the spots of the best-fit models was ∼200 K hotter than the background TOA. We compared our Luhman 16B map with the only previously published map. Interestingly, our map contained a large TOA spot that was cooler (ΔT ∼ 51 K) than the background, which lay at low latitudes, in agreement with the previous Luhman 16B map. Finally, we report the detection of a feature reappearing in Luhman 16B light curves that are separated by tens of hundreds of rotations from each other. We speculate that this feature is related to TOA structures of Luhman 16B.

AB - WISE J104915.57-531906.1 is the nearest brown dwarf binary to our solar system, consisting of two brown dwarfs in the L/T transition: Luhman 16A and B. In this paper, we present the first map of Luhman 16A, and maps of Luhman 16B for two epochs. Our maps were created by applying Aeolus, a Markov-Chain Monte Carlo code that maps the top-of-the-atmosphere (TOA) structure of brown dwarf and other ultracool atmospheres, to light curves of Luhman 16A and B using the Hubble Space Telescope's G141 and G102 grisms. Aeolus retrieved three or four spots in the TOA of Luhman 16A and B, with a surface coverage of 19%-32% (depending on an assumed rotational period of 5 hr or 8 hr) or 21%-38.5% (depending on the observational epoch), respectively. The brightness temperature of the spots of the best-fit models was ∼200 K hotter than the background TOA. We compared our Luhman 16B map with the only previously published map. Interestingly, our map contained a large TOA spot that was cooler (ΔT ∼ 51 K) than the background, which lay at low latitudes, in agreement with the previous Luhman 16B map. Finally, we report the detection of a feature reappearing in Luhman 16B light curves that are separated by tens of hundreds of rotations from each other. We speculate that this feature is related to TOA structures of Luhman 16B.

KW - methods: statistical

KW - stars: individual (WISE J104915.57-531906.1)

KW - techniques: photometric

UR - http://www.scopus.com/inward/record.url?scp=84978483961&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84978483961&partnerID=8YFLogxK

U2 - 10.3847/0004-637X/825/2/90

DO - 10.3847/0004-637X/825/2/90

M3 - Article

AN - SCOPUS:84978483961

VL - 825

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 90

ER -