J/MNRAS/489/3492 IRC+10216 & omi Cet SCUBA-2 light curves (Dharmawardena+, 2019)
The sub-mm variability of IRC+10216 and omicron Ceti.
Dharmawardena T.E., Kemper F., Wouterloot J.G.A, Scicluna P., Marshall J.P,
Wallstrom S.H.J.
<Mon. Not. R. Astron. Soc. 489, 3492 (2019)>
=2019MNRAS.489.3492D 2019MNRAS.489.3492D (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Photometry, millimetric/submm
Keywords: stars: AGB and post-AGB - stars: individual: IRC+10216 -
stars: individual: omicron Ceti - stars: variables: general
Abstract:
We present the sub-mm variability of two of the most well-studied AGB
stars, IRC +10216 and omicron Ceti. The data are obtained at 450 and
850um as part of pointing calibration observations for the James Clerk
Maxwell Telescope's SCUBA-2 instrument over a span of 7yr. The periods
are derived using non-parametric methods, Gatspy Supersmoother and
P4J, in order not to assume an underlying shape to the periodicity.
These were compared to two Lomb-Scargle parametric methods. We find
that for both sources and wavelengths the periods derived from all
methods are consistent within σ. The 850um phase folded light
curves of IRC +10216 show a time lag of ∼540d compared to its optical
counterpart. We explore the origins of the sub-mm variability and the
phase lag using radiative transfer models. Combining the modelling
with findings in the literature, we find that the sub-mm emission and
phase lag can be partially attributed to the dust formation or
destruction cycle. A second, unknown mechanism must be invoked; we
defer an investigation of the origin and nature of this mechanism to a
future work.
Description:
SCUBA-2 light curves for the nearby AGB stars IRC+10216 and omicron
Ceti at 850 and 450 micron from PSF photometry of short calibration
observations.
Objects:
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RA (2000) DE Designation(s)
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02 19 20.79 -02 58 39.5 omicron Cet = NAME Mira
09 47 57.41 +13 16 43.6 IRC+10216 = V* CW Leo
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
cwleo450.dat 53 905 450 micron photometry of IRC+10216 (CW Leo)
cwleo850.dat 53 859 850 micron photometry of IRC+10216 (CW Leo)
mira450.dat 53 613 450 micron photometry of omicron Ceti (Mira)
mira850.dat 54 678 850 micron photometry of omicron Ceti (Mira)
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See also:
J/A+A/592/A42 : A study of dust nucleation in Mira. Part I. (Kaminski+, 2016)
J/ApJS/177/275 : 1.3 and 2mm survey of IRC+10216 (He+, 2008)
J/ApJS/190/348 : 1mm spectral survey of IRC+10216 + VY CMa (Tenenbaum+, 2010)
J/A+A/574/A56 : IRC +10216 17.8GHz-26.3GHz spectrum (Gong+, 2015)
J/A+A/606/A74 : IRC +10216 13.3GHz-18.5GHz spectrum (Zhang+, 2017)
Byte-by-byte Description of file: cwleo?50.dat mira?50.dat
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Bytes Format Units Label Explanations
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1- 16 F16.10 d MJD Date of Observation
18- 36 F19.13 mJy Flux Observed Flux
37- 54 F18.13 mJy e_Flux Uncertainty on observed flux
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Acknowledgements:
Thavisha Dharmawardena, tdharmawardena(at)asiaa.sinica.edu.tw
(End) Patricia Vannier [CDS] 13-Aug-2019