Cloud Atlas: Rotational Modulations in the L/T Transition Brown Dwarf Companion HN Peg B

Yifan Zhou, Daniel Apai, Stanimir Metchev, Ben W.P. Lew, Glenn Schneider, Mark S. Marley, Theodora Karalidi, Elena Manjavacas, Luigi R. Bedin, Nicolas B. Cowan, Paulo A. Miles-Páez, Patrick J. Lowrance, Jacqueline Radigan, Adam J. Burgasser

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Time-resolved observations of brown dwarfs' rotational modulations provide powerful insights into the properties of condensate clouds in ultra-cool atmospheres. Multi-wavelength light curves reveal cloud vertical structures, condensate particle sizes, and cloud morphology, which directly constrain condensate cloud and atmospheric circulation models. We report results from Hubble Space Telescope/Wide Field Camera 3 near-infrared G141 taken in six consecutive orbits observations of HN Peg B, an L/T transition brown dwarf companion to a G0V type star. The best-fit sine wave to the 1.1-1.7 μm broadband light curve has an amplitude of 1.206% ±0.025% and period of 15.4 ±0.5 hr. The modulation amplitude has no detectable wavelength dependence except in the 1.4 μm water absorption band, indicating that the characteristic condensate particle sizes are large (>1 μm). We detect significantly (4.4σ) lower modulation amplitude in the 1.4 μm water absorption band and find that HN Peg B's spectral modulation resembles those of early T type brown dwarfs. We also describe a new empirical interpolation method to remove spectral contamination from the bright host star. This method may be applied in other high-contrast time-resolved observations with WFC3.

Original languageEnglish (US)
Article number132
JournalAstronomical Journal
Volume155
Issue number3
DOIs
StatePublished - Mar 1 2018

Fingerprint

condensate
atlas
condensates
modulation
light curve
particle size
wavelength
absorption spectra
stars
atmospheric circulation
sine waves
Hubble Space Telescope
wavelengths
water
interpolation
near infrared
contamination
cameras
broadband
orbits

Keywords

  • brown dwarfs
  • methods: observational
  • stars: atmospheres

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Zhou, Y., Apai, D., Metchev, S., Lew, B. W. P., Schneider, G., Marley, M. S., ... Burgasser, A. J. (2018). Cloud Atlas: Rotational Modulations in the L/T Transition Brown Dwarf Companion HN Peg B. Astronomical Journal, 155(3), [132]. https://doi.org/10.3847/1538-3881/aaabbd

Cloud Atlas : Rotational Modulations in the L/T Transition Brown Dwarf Companion HN Peg B. / Zhou, Yifan; Apai, Daniel; Metchev, Stanimir; Lew, Ben W.P.; Schneider, Glenn; Marley, Mark S.; Karalidi, Theodora; Manjavacas, Elena; Bedin, Luigi R.; Cowan, Nicolas B.; Miles-Páez, Paulo A.; Lowrance, Patrick J.; Radigan, Jacqueline; Burgasser, Adam J.

In: Astronomical Journal, Vol. 155, No. 3, 132, 01.03.2018.

Research output: Contribution to journalArticle

Zhou, Y, Apai, D, Metchev, S, Lew, BWP, Schneider, G, Marley, MS, Karalidi, T, Manjavacas, E, Bedin, LR, Cowan, NB, Miles-Páez, PA, Lowrance, PJ, Radigan, J & Burgasser, AJ 2018, 'Cloud Atlas: Rotational Modulations in the L/T Transition Brown Dwarf Companion HN Peg B', Astronomical Journal, vol. 155, no. 3, 132. https://doi.org/10.3847/1538-3881/aaabbd
Zhou, Yifan ; Apai, Daniel ; Metchev, Stanimir ; Lew, Ben W.P. ; Schneider, Glenn ; Marley, Mark S. ; Karalidi, Theodora ; Manjavacas, Elena ; Bedin, Luigi R. ; Cowan, Nicolas B. ; Miles-Páez, Paulo A. ; Lowrance, Patrick J. ; Radigan, Jacqueline ; Burgasser, Adam J. / Cloud Atlas : Rotational Modulations in the L/T Transition Brown Dwarf Companion HN Peg B. In: Astronomical Journal. 2018 ; Vol. 155, No. 3.
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