Gaia17bpp
Gaia17bpp is a rare M-type Red giant star that exhibited a single large dimming event (G-16-20.5 mag) over 6.5 years. The variable star is located in the constellation of Sagitta roughly 27,600 ly (8.5 kpc).[1] Current hypothesis and archival data suggest that Gaia17bpp belongs to a rare family of ultra-long period binary stars where the companion is enshrouded in large optically thick disks reminiscent of Epsilon Aurigae, VVV-WIT-07, and AS Leonis Minoris[1][2][3][4]. The proposed secondary star and disk remain unconfirmed due to the copious amount of intervening interstellar dust, and likely due to the remarkable long timescale period of the system.
 An optical image of Gaia17bpp, captured by the Pan-STARRS1 telescope. | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagitta |
| Right ascension | 19h 37m 23.16s |
| Declination | +17° 59′ 02.90″ |
| Characteristics | |
| Evolutionary stage | Red giant branch |
| Spectral type | M0-III |
| J−K color index | 1.7 |
| Astrometry | |
| Parallax (π) | −0.18±0.4 mas. Derived distance using photogeometric distance posterior distribution (Bailer-Jones et al. 2021) |
| Other designations | |
| AT 2017exj 2MASS J19372316+1759029 | |
| Database references | |
| SIMBAD | J19372316+1759029 data |
Gaia17bpp[5] was initially discovered through the ESA's Gaia Photometric Science Alerts[6] (GPSA) in 2022 by astronomers at the University of Washington[7][8]. The remarkable Gaia17bpp dimming event occurred in mid 2012, however the GPSA issued an alert back in 2017 when the star began re-brightening. Due to the large duration of the dimming event, the entirety of the Gaia17bpp dimming event was recovered from several public data archives such as Pan-STARRS, and NASA's Wide-field Infrared Survey Explorer (WISE) where the dimming event was also observed in the near-infrared.
Using both archival image searching, and spectroscopic follow-up observations of Gaia17bpp, researchers were able to eliminate various suspected variable star classes with similar dimming event such as R Coronae Borealis, Cataclysmic variable star, or Young stellar object.
Modeling of the dimming event suggest that a possible scenario includes the occultation of an extended oblate optically thick disk with 1.4 AU radius, moving with a transverse velocity of approximately 0.005 km/s[1]. It is unclear how such large optically thick disks can form such in the case of Gaia17bpp and other analog systems. One study suggests that previous mass-trasfer interaction between a close binary can produce large disks and lose angular momentum to produce the observed long period binary system[9].
See also
References
- ^ a b c Tzanidakis, Anastasios; Davenport, James R. A.; Bellm, Eric C.; Wang, Yuankun (2023-09-01). "Gaia17bpp: A Giant Star with the Deepest and Longest Known Dimming Event". The Astrophysical Journal. 955 (1): 69. doi:10.3847/1538-4357/aceda7. ISSN 0004-637X.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ Kloppenborg, Brian; Stencel, Robert; Monnier, John D.; Schaefer, Gail; Zhao, Ming; Baron, Fabien; McAlister, Hal; ten Brummelaar, Theo; Che, Xiao; Farrington, Chris; Pedretti, Ettore; Sallave-Goldfinger, P. J.; Sturmann, Judit; Sturmann, Laszlo; Thureau, Nathalie (2010-04-01). "Infrared images of the transiting disk in the ɛ Aurigae system". Nature. 464: 870–872. doi:10.1038/nature08968. ISSN 0028-0836.
- ^ Lipunov, V.; Gorbovskoy, E.; Afanasiev, V.; Tatarnikova, A.; Denisenko, D.; Makarov, D.; Tiurina, N.; Krushinsky, V.; Vinokurov, A.; Balanutsa, P.; Kuznetsov, A.; Gress, O.; Sergienko, Yu.; Yurkov, V.; Gabovich, A. (2016-04-01). "Discovery of an unusual bright eclipsing binary with the longest known period: TYC 2505-672-1/MASTER OT J095310.04+335352.8". Astronomy and Astrophysics. 588: A90. doi:10.1051/0004-6361/201526528. ISSN 0004-6361.
- ^ Smith, Leigh C.; Koposov, Sergey E.; Lucas, Philip W.; Sanders, Jason L.; Minniti, Dante; Udalski, Andrzej; Evans, N. Wyn; Aguado, David; Ivanov, Valentin D.; Saito, Roberto K.; Fraga, Luciano; Pietrukowicz, Pawel; Penoyre, Zephyr; González-Fernández, Carlos (2021-08-01). "VVV-WIT-08: the giant star that blinked". Monthly Notices of the Royal Astronomical Society. 505: 1992–2008. doi:10.1093/mnras/stab1211. ISSN 0035-8711.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ "Gaia17bpp". gsaweb.ast.cam.ac.uk. Retrieved 2024-01-08.
- ^ Hodgkin, S. T.; Harrison, D. L.; Breedt, E.; Wevers, T.; Rixon, G.; Delgado, A.; Yoldas, A.; Kostrzewa-Rutkowska, Z.; Wyrzykowski, Ł.; van Leeuwen, M.; Blagorodnova, N.; Campbell, H.; Eappachen, D.; Fraser, M.; Ihanec, N. (2021-08-01). "Gaia Early Data Release 3. Gaia photometric science alerts". Astronomy and Astrophysics. 652: A76. doi:10.1051/0004-6361/202140735. ISSN 0004-6361.
- ^ Strickland, Ashley (2023-01-11). "Unusually brightening star captures attention as a stellar oddity". CNN. Retrieved 2024-01-08.
- ^ "The seven-year photobomb: Distant star's dimming was likely a 'dusty' companion getting in the way, astronomers say". UW News. Retrieved 2024-01-08.
- ^ Gibson, Justus (13 March 2018). "MESA models of the evolutionary state of the interacting binary epsilon Aurigae". academic.oup.com. Retrieved 2024-01-08.
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