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. It is located in the Sagitta constellation and is about 27,600 light years away from Earth.
 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[a] |
| Other designations | |
AT 2017exj, 2MASS J19372316+1759029, Gaia DR3 1824311891830344704 | |
| Database references | |
| SIMBAD | data |
Astronomical characteristics
editThe 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.
Discovery and dimming event
edit
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.
Researchers employed archival image searching and conducted spectroscopic follow-up observations on Gaia17bpp using the Apache Point Observatory 3.5m ARC Telescope.[9] Throughout their analysis, they successfully ruled out several 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-transfer interaction between a close binary can produce large disks and lose angular momentum to produce the observed long period binary system.[10]
See also
editNotes
edit- ^ Derived distance using photogeometric distance posterior distribution (Bailer-Jones et al. 2021)
References
edit- ^ a b c d 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. arXiv:2306.12409. Bibcode:2023ApJ...955...69T. doi:10.3847/1538-4357/aceda7. ISSN 0004-637X.
- ^ 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 (7290): 870–872. arXiv:1004.2464. Bibcode:2010Natur.464..870K. doi:10.1038/nature08968. ISSN 0028-0836. PMID 20376144. S2CID 18866716.
- ^ 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. arXiv:1602.06010. Bibcode:2016A&A...588A..90L. 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 (2): 1992–2008. arXiv:2106.05300. Bibcode:2021MNRAS.505.1992S. doi:10.1093/mnras/stab1211. ISSN 0035-8711.
- ^ "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. arXiv:2106.01394. Bibcode:2021A&A...652A..76H. 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.
- ^ "ARC". arc.apo.nmsu.edu. 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.