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Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses
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Pulsed accretion in a variable protostar.

James Muzerolle1, Elise Furlan, Kevin Flaherty

  • 1Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, Maryland 21218, USA. muzerol@stsci.edu

Nature
|January 4, 2013
PubMed
Summary
This summary is machine-generated.

Young protostars exhibit pulsed accretion, a phenomenon where luminosity periodically increases due to variable accretion rates. This study observed a protostar with a surprising, regular tenfold infrared luminosity increase every 25.34 days.

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Area of Science:

  • Astrophysics
  • Stellar Evolution
  • Exoplanet Research

Background:

  • Pre-main-sequence close binary stars accrete material from circumbinary disks.
  • Pulsed accretion, characterized by periodic luminosity increases, influences binary evolution and planet formation.
  • Accretion variability is common in young stars, but periodic pulsed accretion signals are rarely observed in young binaries.

Purpose of the Study:

  • To investigate periodic luminosity variations in a young protostar.
  • To determine if the observed variations are consistent with pulsed accretion.
  • To understand the implications of strong, regular pulsed accretion in very young stellar systems.

Main Methods:

  • Multi-epoch infrared observations of a young protostar.
  • Analysis of luminosity variations over time.
  • Comparison of observed patterns with theoretical models of pulsed accretion.

Main Results:

  • A young protostar (age ~10^5 years) showed a tenfold increase in infrared luminosity over approximately one week.
  • This luminosity increase recurred with remarkable regularity every 25.34 days.
  • The observed phenomenon is attributed to pulsed accretion from an unseen binary companion.

Conclusions:

  • The observed pulsed accretion signal is unusually strong and regular for a system of this young age.
  • This finding suggests that pulsed accretion may play a significant role in the early evolution of close binary stars.
  • The regularity and strength of the signal may be linked to the protostar's very young age compared to previously studied systems.