Successful telescope proposal: Where are the mid-sized flares of ultracool M dwarfs?

Katja Poppenhaeger

Research output: Other contribution

Abstract

We propose to observe the M8.5 dwarf SCR J1845-6357 with XMM-Newton EPIC for 60 ks. Very low-mass M dwarfs show a distinct drop in X-ray luminosity compared to slightly more massive M dwarfs. Surprisingly, this does not happen at the mass threshold where M dwarfs become fully convective (M4), but at significantly lower masses (M8). These very low mass stars seem to have a flaring behaviour different from earlier type stars: they display either occasional large flares or a very low-level "flickering" in their X-ray light curves, but not the canonical power-law flare-energy distribution observed for the Sun and other cool stars. Our aim is to collect a long-duration light curve for one of the most nearby ultracool dwarfs to quantify how its flare-energy distribution differs from earlier type stars.
Original languageEnglish
TypeAccepted observing proposal
Publication statusPublished - 01 Oct 2013

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flares
proposals
telescopes
light curve
silicon controlled rectifiers
stars
XMM-Newton telescope
newton
energy distribution
sun
thresholds
x rays

Keywords

  • Stars
  • White Dwarfs
  • Solar System
  • SCR J1845-6357

Cite this

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title = "Successful telescope proposal: Where are the mid-sized flares of ultracool M dwarfs?",
abstract = "We propose to observe the M8.5 dwarf SCR J1845-6357 with XMM-Newton EPIC for 60 ks. Very low-mass M dwarfs show a distinct drop in X-ray luminosity compared to slightly more massive M dwarfs. Surprisingly, this does not happen at the mass threshold where M dwarfs become fully convective (M4), but at significantly lower masses (M8). These very low mass stars seem to have a flaring behaviour different from earlier type stars: they display either occasional large flares or a very low-level {"}flickering{"} in their X-ray light curves, but not the canonical power-law flare-energy distribution observed for the Sun and other cool stars. Our aim is to collect a long-duration light curve for one of the most nearby ultracool dwarfs to quantify how its flare-energy distribution differs from earlier type stars.",
keywords = "Stars, White Dwarfs, Solar System, SCR J1845-6357",
author = "Katja Poppenhaeger",
year = "2013",
month = "10",
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language = "English",
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Successful telescope proposal: Where are the mid-sized flares of ultracool M dwarfs? / Poppenhaeger, Katja.

2013, Accepted observing proposal.

Research output: Other contribution

TY - GEN

T1 - Successful telescope proposal: Where are the mid-sized flares of ultracool M dwarfs?

AU - Poppenhaeger, Katja

PY - 2013/10/1

Y1 - 2013/10/1

N2 - We propose to observe the M8.5 dwarf SCR J1845-6357 with XMM-Newton EPIC for 60 ks. Very low-mass M dwarfs show a distinct drop in X-ray luminosity compared to slightly more massive M dwarfs. Surprisingly, this does not happen at the mass threshold where M dwarfs become fully convective (M4), but at significantly lower masses (M8). These very low mass stars seem to have a flaring behaviour different from earlier type stars: they display either occasional large flares or a very low-level "flickering" in their X-ray light curves, but not the canonical power-law flare-energy distribution observed for the Sun and other cool stars. Our aim is to collect a long-duration light curve for one of the most nearby ultracool dwarfs to quantify how its flare-energy distribution differs from earlier type stars.

AB - We propose to observe the M8.5 dwarf SCR J1845-6357 with XMM-Newton EPIC for 60 ks. Very low-mass M dwarfs show a distinct drop in X-ray luminosity compared to slightly more massive M dwarfs. Surprisingly, this does not happen at the mass threshold where M dwarfs become fully convective (M4), but at significantly lower masses (M8). These very low mass stars seem to have a flaring behaviour different from earlier type stars: they display either occasional large flares or a very low-level "flickering" in their X-ray light curves, but not the canonical power-law flare-energy distribution observed for the Sun and other cool stars. Our aim is to collect a long-duration light curve for one of the most nearby ultracool dwarfs to quantify how its flare-energy distribution differs from earlier type stars.

KW - Stars

KW - White Dwarfs

KW - Solar System

KW - SCR J1845-6357

M3 - Other contribution

ER -