Discovery of a Hot Symbiotic Star in the Cold Antarctic Sky: Symbiotics Are Outliers in SkyMapper uvgriz Photometry

• Published in: Research Notes of the AAS
• Main Authors: Lucy, Adrian B., Sokoloski, J. L., Nuñez, Natalia Edith, Wolf, C., Bohlsen, T., Luna, Gerardo Juan Manuel
• Format: Article in Journal/Newspaper
• Language: English
• Published: IOP
• Subjects: SYMBIOTIC; SKYMAPPER; https://purl.org/becyt/ford/1.3; https://purl.org/becyt/ford/1; Antarctic; San Juan; Argentina; Edith; Antarc*
• Online Access: http://hdl.handle.net/11336/80669

Using near-ultraviolet flux excess and variability from the SkyMapper Southern Sky Survey11 as novel diagnostics to search for symbiotic stars?cool giants accreting onto compact objects, typically white dwarfs (WDs), we report that Hen 3-1768 (≡ASAS J195948?8252.7) is a symbiotic star. It may be an optimal target for continuous monitoring by Antarctic telescopes; at a decl. of −82877, it is now the closest known symbiotic to either geographic pole, and the only known symbiotic more southern than the Small Magellanic Cloud (Belczyński et al. 2000; Akras et al. 2019, ApJS, in press). Figure 1 shows that Hen 3-1768 produced unambiguous emission from Raman O vi 6830,7088 Å, He ii 4686 Å, and other transitions, proving that it is a symbiotic star (e.g., Shore et al. 2014). Comparing to Pickles (1998) template spectra, we preliminarily constrained the giant donor´s spectral type to between K4 and K7, making Hen 3-1768 one of the dozen or so yellow symbiotics with stellar-type infrared (IR) colors currently known (e.g., Baella et al. 2016). The 2MASS IR colors (J − H)0 = 0.82 and (H − Ks)0 = 0.21 (Skrutskie et al. 2006; de-reddened by total Galactic extinction12 ) are consistent with this conclusion (see Figure 1 in Baella et al. 2016). Fil: Lucy, Adrian B. Columbia University; Estados Unidos Fil: Sokoloski, J. L. Columbia University; Estados Unidos Fil: Nuñez, Natalia Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; Argentina Fil: Wolf, C. Research School Of Astronomy And Astrophysics, Anu; Australia Fil: Bohlsen, T. Mirranook Observatory,; Australia Fil: Luna, Gerardo Juan Manuel. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. ...