Bow-Shock Nebula Associated with Novalike Variable ASASSN-V J205457.73+515731.9

ATel #13825; Howard E. Bond (Penn State U)
on 22 Jun 2020; 23:36 UT
Credential Certification: Howard E. Bond (heb11@astro.psu.edu)

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In a recent Astronomer's Telegram, Jayasinghe et al. (ATel 13824) announced the discovery of a novalike variable star, ASASSN-V J205457.73+515731.9, currently undergoing a dimming episode similar to those of the VY Sculptoris class of cataclysmic variables. Inspection of the Digitized Sky Survey images of the object show that it is associated with a faint nebula, of approximate dimensions 3x4 arcmin. The nebula is brightest in the red image, suggesting that it is bright in H-alpha. The variable star is located near the eastern edge of the nebula, and the structure of the nebula resembles a bow shock. To my knowledge, although it is readily visible on the DSS images, the nebula has not previously been cataloged. Remarkably similar nebulae are associated with the novalike stars BZ Cam and V341 Ara (see Bond et al., 2018, PASP, 130, 094201; https://ui.adsabs.harvard.edu/abs/2018PASP..130i4201B%2F/abstract). Interestingly, the absolute magnitudes of all three variable stars are very similar, about visual absolute magnitude +4.8. In all three objects, the stars lie near the edge of the nebulae, which all have bow-shock morphology. In all three objects, the direction of the proper motion of the star is in the direction of the bow shock.