J/other/Nat/493.378 LRL 54361 Spitzer light curves (Muzerolle+, 2013)
Pulsed accretion in a variable protostar.
Muzerolle J., Furlan E., Flaherty K., Balog Z., Gutermuth R.
<Nature, 493, 378-380 (2013)>
=2013Natur.493..378M 2013Natur.493..378M
ADC_Keywords: Stars, variable ; Photometry, infrared
Abstract:
Periodic increases in luminosity arising from variable accretion rates
have been predicted for some pre-main-sequence close binary stars as
they grow from circumbinary disks. The phenomenon is known as
pulsed accretion and can affect the orbital evolution and mass
distribution of young binaries, as well as the potential for
planet formation. Accretion variability is a common feature of
young stars, with a large range of amplitudes and timescales as
measured from multi-epoch observations at optical and infrared
wavelengths. Periodic variations consistent with pulsed accretion have
been seen in only a few young binaries via optical accretion
tracers albeit intermittently with accretion luminosity
variations ranging from zero to 50 per cent from orbit to orbit. Here
we report that the infrared luminosity of a young protostar (of age
about 105 years) increases by a factor of ten in roughly one week
every 25.34 days. We attribute this to pulsed accretion associated
with an unseen binary companion. The strength and regularity of this
accretion signal is surprising; it may be related to the very young
age of the system, which is a factor of ten younger than the other
pulsed accretors previously studied.
Description:
We obtained multi-epoch mid-infrared (MIR) observations of the star
forming region IC 348 using the Spitzer Space Telescope. Among the
roughly 300 pre-main-sequence objects in the cluster, the protostar
LRLL 54361 (which we refer to here as L54361) exhibits by far the
largest MIR flux variability. We have a total of 81 separate
observations of L54361 taken with all three instruments on board
Spitzer.
Objects:
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RA (2000) DE Designation(s)
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03 43 51.02 +32 03 08.1 Cl* IC 348 LRL 54361 = SSTc2d J034351.0+320308
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tables2.dat 61 65 Spitzer IRAC photometry
tables3.dat 30 10 Spitzer MIPS photometry
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Byte-by-byte Description of file: tables2.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 d MJD Modified Julian date
11- 16 F6.3 mag [3.6] Spitzer IRAC 3.6um magnitude
18- 22 F5.3 mag e_[3.6] rms uncertainty on [3.6]
24- 29 F6.3 mag [4.5] Spitzer IRAC 4.5um magnitude
31- 35 F5.3 mag e_[4.5] rms uncertainty on [4.5]
37- 42 F6.3 mag [5.8] ? Spitzer IRAC 5.8um magnitude (1)
44- 48 F5.3 mag e_[5.8] ? rms uncertainty on [5.8]
50- 55 F6.3 mag [8.0] ? Spitzer IRAC 8.0um magnitude (1)
57- 61 F5.3 mag e_[8.0] ? rms uncertainty on [8.0]
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Note (1): All entries with missing 5.8 and 8 micron photometry correspond to
data taken during warm operations.
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Byte-by-byte Description of file: tables3.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 d MJD Modified Julian date
11- 14 F4.2 mag [24] Spitzer MIPS 24um magnitude
16- 19 F4.2 mag e_[24] rms uncertainty on [24]
21- 25 F5.2 mag [70] ? Spitzer MIPS 70um magnitude (1)
27- 30 F4.2 mag e_[70] ? rms uncertainty on [70]
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Note (1): The third entry contains no 70 micron data because the scan pattern
has a gap at the position of the source.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 05-Feb-2013