Harold Corwin

IC 1007 is almost surely the galaxy listed in the position table; Javelle's micrometric position is within two arcseconds of the modern positions from e.g. Gaia DR2, SDSS, Pan-STARRS, 2MASS, and so on.

Yet, as Steve Gottlieb pointed out in an email to me in March 2020, Javelle also mentions a nearby star that apparently no longer exists. His full description reads (translated from the French by me), "Very faint, small, round, 15[arcseconds] in diameter, slightly condensed, near a star of magnitude 10.5." There is no star that bright within fifteen arcminutes of the galaxy.

Steve wonders if the star could be an asteroid. But a search of the JPL small-bodies database (https://ssd.jpl.nasa.gov/sbfind.cgi) using their search tool set to the correct parameters (Nice Observatory, 17 June 1892, roughly midnight, all asteroids brighter than 16, again within 15 arcminutes of the galaxy) turns up nothing.

I had thought that there might have been a supernova in the inner ring of the galaxy (that ring is quite remarkable: it is blue in the SDSS and PS1 images, is rather patchy, and is virtually complete around the red nucleus). I had wondered if Javelle saw a supernova in the ring. Since the distance modulus of the galaxy is about 35.5 (given its redshift; see NED for confirmation), I would expect a Type-Ia supernova to have an apparent magnitude of around 16-17 if it were "normal" with an absolute magnitude of -18 to -19. This is far fainter than Javelle's estimate, so it's *highly* unlikely that his "nearby star" is a supernova.

All this leaves us with the question "What did Javelle see that led him to record a "nearby star of magnitude 10.5"? Steve has uncovered another mystery!

― IC Notes by Harold Corwin

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