J/A+A/637/A20 AT 2019abn: multi-wavelength observations (Williams+, 2020)
AT 2019abn: multi-wavelength observations over the first 200 days.
Williams S.C., Jones D., Pessev P., Geier S., Corradi R.L.M., Hook I.M.,
Darnley M.J., Pejcha O., Nunez A., Meingast S., Moran S.
<Astron. Astrophys. 637, A20 (2020)>
=2020A&A...637A..20W 2020A&A...637A..20W (SIMBAD/NED BibCode)
ADC_Keywords: Supernovae ; Photometry
Keywords: galaxies: individual: M51 - stars: AGB and post-AGB -
stars: mass-loss - stars: variables: general -
stars: winds, outflows - supernovae: AT 2019abn
Abstract:
AT 2019abn was discovered in the nearby M51 galaxy by the Zwicky
Transient Facility at more than two magnitudes and around three weeks
prior to its optical peak. We aim to conduct a detailed photometric
and spectroscopic follow-up campaign for AT 2019abn, with early
discovery allowing for significant pre-maximum observations of an
intermediate luminosity red transient (ILRT) for the first time. This
work is based on the analysis of u'BVr'i'z'H photometry and
low-resolution spectroscopy using the Liverpool Telescope,
medium-resolution spectroscopy with the Gran Telescopio Canarias
(GTC), and near-infrared imaging with the GTC and the Nordic Optical
Telescope. We present the most detailed optical light curve of an ILRT
to date, with multi-band photometry starting around three weeks before
peak brightness. The transient peaked at an observed absolute
magnitude of Mr=-13.1, although it is subject to significant
reddening from dust in M51, implying an intrinsic Mr~-15.2. The
initial light curve showed a linear, achromatic rise in magnitude
before becoming bluer at peak. After peak brightness, the transient
gradually cooled. This is reflected in our spectra, which at later
times show absorption from such species as FeI, NiI and LiI. A
spectrum taken around peak brightness shows narrow, low-velocity
absorption lines, which we interpret as likely to originate from
pre-existing circumstellar material. We conclude that while there are
some peculiarities, such as the radius evolution, AT 2019abn fits in
well overall with the ILRT class of objects and is the most luminous
member of the class seen to date.
Description:
Optical and NIR photometry of AT 2019abn. All measurements are in the
AB system and not corrected for any extinction. As in the main text,
't' refers to the time since the first optical detection.
Objects:
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RA (2000) DE Designation(s)
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13 29 42.39 +47 11 17.0 AT 2019abn = NAME M51 OT2019-1
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 48 233 Optical and NIR photometry of AT 2019abn
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 8 F8.2 d MJD MJD date of observations
10- 15 F6.2 d t Time since discovery
17- 26 A10 --- Inst Telescope and instrument used
28- 29 A2 --- Filter Filter used: u', B, V, r', i', z', J, H, Ks
39- 43 F5.2 mag mag Apparent AB magnitude in Filter
45- 48 F4.2 mag e_mag Apparent AB magnitude uncertainty
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Acknowledgements:
Steven Williams, steven.williams(at)utu.fi
(End) Patricia Vannier [CDS] 04-Mar-2020