Low-gravity L Dwarfs Are Likely More Variable

Stanimir Metchev; Aren Heinze; Daniel Apai; Davin Flateau; Jacqueline Radigan; Adam Burgasser; Mark Marley; Étienne Artigau; Peter Plavchan; Bertrand Goldman

doi:10.1017/S1743921315006523

Low-gravity L Dwarfs Are Likely More Variable

Stanimir Metchev, Aren Heinze, Daniel Apai, Davin Flateau, Jacqueline Radigan, Adam Burgasser, Mark Marley, Étienne Artigau, Peter Plavchan, Bertrand Goldman

Research output: Contribution to journal › Article › peer-review

Abstract

In the Weather on Other Worlds Spitzer Exploration Science program, we surveyed 44 nearby L3-T8 dwarfs for spot-induced rotational variability. Among single L3-L9.5 dwarfs, we found that 80% are variable at >0.2% in the 3-5 μm wavelength range, while 36% of T0-T8 were variable at >0.4%. Taking into account viewing angle and sensitivity considerations, both of these findings are consistent with spots being present on ∼100% of L3-T8 dwarfs. Intriguingly, we find a tentative association (92% confidence) between low surface gravity and high-amplitude variability among L3-L5.5 dwarfs. Although we can not confirm whether lower gravity is also correlated with a higher incidence of variables, the result is promising for the characterization of directly imaged young extrasolar planets through variability.

Original language	English (US)
Pages (from-to)	121-123
Number of pages	3
Journal	Proceedings of the International Astronomical Union
Volume	10
DOIs	https://doi.org/10.1017/S1743921315006523
State	Published - 2015

Keywords

brown dwarfs
stars: low-mass
stars: starspots
stars: variables: general
stars:rotation
techniques: photometric

ASJC Scopus subject areas

Medicine (miscellaneous)
Astronomy and Astrophysics
Nutrition and Dietetics
Public Health, Environmental and Occupational Health
Space and Planetary Science

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10.1017/S1743921315006523

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@article{47f61c0e76e5419980ac716427c7a252,

title = "Low-gravity L Dwarfs Are Likely More Variable",

abstract = "In the Weather on Other Worlds Spitzer Exploration Science program, we surveyed 44 nearby L3-T8 dwarfs for spot-induced rotational variability. Among single L3-L9.5 dwarfs, we found that 80% are variable at >0.2% in the 3-5 μm wavelength range, while 36% of T0-T8 were variable at >0.4%. Taking into account viewing angle and sensitivity considerations, both of these findings are consistent with spots being present on ∼100% of L3-T8 dwarfs. Intriguingly, we find a tentative association (92% confidence) between low surface gravity and high-amplitude variability among L3-L5.5 dwarfs. Although we can not confirm whether lower gravity is also correlated with a higher incidence of variables, the result is promising for the characterization of directly imaged young extrasolar planets through variability.",

keywords = "brown dwarfs, stars: low-mass, stars: starspots, stars: variables: general, stars:rotation, techniques: photometric",

author = "Stanimir Metchev and Aren Heinze and Daniel Apai and Davin Flateau and Jacqueline Radigan and Adam Burgasser and Mark Marley and {\'E}tienne Artigau and Peter Plavchan and Bertrand Goldman",

note = "Publisher Copyright: {\textcopyright} 2016 International Astronomical Union.",

year = "2015",

doi = "10.1017/S1743921315006523",

language = "English (US)",

volume = "10",

pages = "121--123",

journal = "Proceedings of the International Astronomical Union",

issn = "1743-9213",

publisher = "Cambridge University Press",

}

TY - JOUR

T1 - Low-gravity L Dwarfs Are Likely More Variable

AU - Metchev, Stanimir

AU - Heinze, Aren

AU - Apai, Daniel

AU - Flateau, Davin

AU - Radigan, Jacqueline

AU - Burgasser, Adam

AU - Marley, Mark

AU - Artigau, Étienne

AU - Plavchan, Peter

AU - Goldman, Bertrand

PY - 2015

Y1 - 2015

N2 - In the Weather on Other Worlds Spitzer Exploration Science program, we surveyed 44 nearby L3-T8 dwarfs for spot-induced rotational variability. Among single L3-L9.5 dwarfs, we found that 80% are variable at >0.2% in the 3-5 μm wavelength range, while 36% of T0-T8 were variable at >0.4%. Taking into account viewing angle and sensitivity considerations, both of these findings are consistent with spots being present on ∼100% of L3-T8 dwarfs. Intriguingly, we find a tentative association (92% confidence) between low surface gravity and high-amplitude variability among L3-L5.5 dwarfs. Although we can not confirm whether lower gravity is also correlated with a higher incidence of variables, the result is promising for the characterization of directly imaged young extrasolar planets through variability.

AB - In the Weather on Other Worlds Spitzer Exploration Science program, we surveyed 44 nearby L3-T8 dwarfs for spot-induced rotational variability. Among single L3-L9.5 dwarfs, we found that 80% are variable at >0.2% in the 3-5 μm wavelength range, while 36% of T0-T8 were variable at >0.4%. Taking into account viewing angle and sensitivity considerations, both of these findings are consistent with spots being present on ∼100% of L3-T8 dwarfs. Intriguingly, we find a tentative association (92% confidence) between low surface gravity and high-amplitude variability among L3-L5.5 dwarfs. Although we can not confirm whether lower gravity is also correlated with a higher incidence of variables, the result is promising for the characterization of directly imaged young extrasolar planets through variability.

KW - brown dwarfs

KW - stars: low-mass

KW - stars: starspots

KW - stars: variables: general

KW - stars:rotation

KW - techniques: photometric

UR - http://www.scopus.com/inward/record.url?scp=84956487383&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84956487383&partnerID=8YFLogxK

U2 - 10.1017/S1743921315006523

DO - 10.1017/S1743921315006523

M3 - Article

SN - 1743-9213

VL - 10

SP - 121

EP - 123

JO - Proceedings of the International Astronomical Union

JF - Proceedings of the International Astronomical Union

ER -

Low-gravity L Dwarfs Are Likely More Variable

Abstract

Keywords

ASJC Scopus subject areas

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