J/ApJ/955/69 Gaia17bpp opt-NIR LCs from 1950s to the present (Tzanidakis+, 2023)
Gaia17bpp: a giant star with the deepest and longest known dimming event.
Tzanidakis A., Davenport J.R.A., Bellm E.C., Wang Y.
<Astrophys. J., 955, 69 (2023)>
=2023ApJ...955...69T 2023ApJ...955...69T
ADC_Keywords: Stars, double and multiple; Photometry; Optical; Infrared
Keywords: Stellar occultation ; Binary stars ; Peculiar variable stars
Abstract:
We report the serendipitous discovery of Gaia17bpp /
2MASS_J19372316+1759029, a binary star with a deep single
large-amplitude dimming event of ∼4.5mag that lasted over 6.5yr. Using
the optical-to-IR spectral energy distribution (SED), we constrain the
primary star to be a cool giant M0III star with effective temperature
Teff=3850K and radius R=58R☉. Based on the SED fitting, we
obtained a bimodal posterior distribution of primary stellar masses
with a stronger preference for a 1.5M☉ mass star. Within the
last 66yr of photometric coverage, no other significant dimming events
of this depth and duration were identified in the optical light
curves. Using a Gaussian process, we fit a generalized Gaussian
distribution to the optical and IR light curves and conclude that the
dimming event exhibits moderate asymmetries from optical to IR. At the
minimum of the dimming event, the Wide- field Infrared Survey Explorer
color (W1-W2) differed by ∼0.2mag relative to the primary star color
outside the dimming event. The ingress and egress colors show a
shallow reddening profile. We suggest that the main culprit of the
dimming event is likely due to the presence of a large, optically
thick disk transiting the primary giant star. By fitting a
monochromatic transit model of an oblate disk transiting a star, we
found good agreement with a slow-moving (0.005km/s) disk with a ∼1.4au
radius. We propose that Gaia17bpp belongs to a rare binary star
population similar to the ε Aurigae system, which consists of
a secondary star enshrouded by an optically thick debris disk.
Description:
Collated time-series photometric measurements from multiple public
all-sky surveys (including Gaia, WISE, PS1, GALEX, TESS) have been
combined to generate a mosaic light curve of Gaia17bpp spanning from
the late 1950s to the present. See Section 2.
Gaia17bpp was observed with the Apache Point Observatory (APO) ARC
3.5m telescope using a medium-dispersion spectrograph KOSMOS on
2022-Sep-18. We used the red high slit configuration with wavelength
coverage between 6150 and 9800Å. Our on-sky time included one
30-minute exposure with clear sky conditions. See Section 2.5.
On 2023-May-07 we performed follow-up photometry on Gaia17bpp with the
APO 3.5m Astrophysical Research Consortium Telescope Imaging Camera
(ARCTIC) using the Sloan Digital Sky Survey (SDSS) u filter.
See Section 2.6.
Objects:
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RA (ICRS) DE Designation(s)
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19 37 23.15 +17 59 02.9 Gaia17bpp = 2MASS J19372316+1759029
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig3.dat 34 1967 Historical optical-NIR light curve of Gaia17bpp
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See also:
I/284 : The USNO-B1.0 Catalog (Monet+ 2003)
I/324 : The Initial Gaia Source List (IGSL) (Smart, 2013)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
I/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)
J/A+A/539/A51 : Catalogue enriched with R CrB stars (Tisserand, 2012)
J/ApJ/792/30 : NEOWISE magnitudes for near-Earth objects (Mainzer+, 2014)
J/AJ/147/9 : VRIJHK light curves of V582 Mon (Windemuth+, 2014)
J/AJ/151/90 : Spitzer & VRIJHK photometry of V582 Mon (Arulanantham+, 2016)
J/A+A/605/A111 : Surface rotation of Kepler red giant stars (Ceillier+, 2017)
J/AJ/156/71 : K2 C2: young disk-bearing stars in Sco & Oph (Cody+, 2018)
J/A+A/635/A14 : New R Coronae Borealis stars (Tisserand+, 2020)
J/A+A/652/A76 : Gaia Photometric Science Alerts (Hodgkin+, 2021)
J/A+A/649/A3 : Gaia EDR3 photometric passbands (Riello+, 2021)
J/MNRAS/513/2719 : Stellar parameters study with SED fit algo (Vines+, 2022)
J/ApJ/933/L21 : g and i bands LCs of Bernhard-2 star (Zhu+, 2022)
Byte-by-byte Description of file: fig3.dat
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Bytes Format Units Label Explanations
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1- 13 F13.7 d MJD [55306.09/59739.9] Modified Julian Date
15- 20 F6.3 mag mag [9.6/21.1] Apparent magnitude in Filter
22- 26 F5.3 mag e_mag [0.002/0.4] Uncertainty in mag
28- 34 A7 --- Filter Filter used
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 01-Dec-2025