HV 11417 is a candidate Thorne–Żytkow object in the Small Magellanic Cloud, put forward in a paper by Emma Beasor and collaborators. The paper also claims that another candidate for the Thorne–Żytkow object, HV 2112, was not a Thorne–Żytkow object because it seemingly lacked any distinguishing quality which would indicate that classification.[4] It has since been reported that HV 11417 may be a foreground halo star.[10] As of Gaia's 3rd data release the star has been measured to have a negative measured parallax suggesting a distance of more than 103,000 light-years (32,000 pc) at the 3-sigma level, and a proper motion consistent with Small Magellanic Cloud stars in its region of the galaxy.[2]
Notes
↑Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K:
↑Boyer, Martha L.; Srinivasan, Sundar; Van Loon, Jacco Th.; McDonald, Iain; Meixner, Margaret; Zaritsky, Dennis; Gordon, Karl D.; Kemper, F. et al. (2011). "Surveying the Agents of Galaxy Evolution in the Tidally Stripped, Low Metallicity Small Magellanic Cloud (SAGE-SMC). II. Cool Evolved Stars". The Astronomical Journal142 (4): 103. doi:10.1088/0004-6256/142/4/103. Bibcode: 2011AJ....142..103B.
↑Elias, J. H.; Frogel, J. A.; Humphreys, R. M. (1980). "HV 11417 : A peculiar M supergiant in the Small Magellanic Cloud". The Astrophysical Journal242: L13. doi:10.1086/183391. Bibcode: 1980ApJ...242L..13E.
↑Martínez-Miravé, Pablo; Tamborra, Irene; Vigna-Gómez, Alejandro (2025). "Identifying Thorne–Żytkow Objects through Neutrinos". The Astrophysical Journal984 (1): L2. doi:10.3847/2041-8213/adc8ab. Bibcode: 2025ApJ...984L...2M.
↑Patrick, L. R.; Thilker, D.; Lennon, D. J.; Bianchi, L.; Schootemeijer, A.; Dorda, R.; Langer, N.; Negueruela, I. (2022). "Red supergiant stars in binary systems. I. Identification and characterization in the small magellanic cloud from the UVIT ultraviolet imaging survey". Monthly Notices of the Royal Astronomical Society513 (4): 5847. doi:10.1093/mnras/stac1139. Bibcode: 2022MNRAS.513.5847P.
↑ 8.08.18.2Massey, Philip; Neugent, Kathryn F.; Ekström, Sylvia; Georgy, Cyril; Meynet, Georges (2023). "The Time-averaged Mass-loss Rates of Red Supergiants as Revealed by Their Luminosity Functions in M31 and M33". The Astrophysical Journal942 (2): 69. doi:10.3847/1538-4357/aca665. Bibcode: 2023ApJ...942...69M.
↑O'Grady, Anna (2020). "Cool, Luminous, and Highly Variable Stars in the Magellanic Clouds from ASAS-SN: Implications for Thorne-Żytkow Objects and Super-asymptotic Giant Branch Stars". Astrophysical Journal901 (2): 135. September 2020. doi:10.3847/1538-4357/abafad. Bibcode: 2020ApJ...901..135O.