Proposal #628

V418 Cas is a long-period Mira variable. It was discovered by Hoffmeister in the 1960's, and an initial study by Gessner and Meinunger gave a period of 480 days. It was independently detected by Kaiser and Collins who covered two maxima, in 1989 and 1991. They concluded their 1991 study that it is a "Mira variable with a long period, a very large and, indeed, still unknown total amplitude, and an unusually rapid rise to maximum." (Kaiser and Collins, 1991).

The AAVSO International Database currently contains 410 observations with only a handful observations since 2006; thus, several maxima have gone undetected in AAVSO data.

The suggestion for this proposal is to observe this object for a number of periods to investigate the total amplitude, characterize the rise to maximum, and provide data for future updating of the elements.

The ephemeris based on the elements currently given in the VSX shows the following upcoming maxima:

2460910 22 Aug 2025
2461393 18 Dec 2026
2461876 14 Apr 2028

It should be noted that the minimum magnitude given in VSX is <17.8 V, and since it seems impossible to enter a "fainter than" number, I just wrote 19 in that field.

Kaiser, Daniel H., and Michael J. Collins. ”Period Update for V418 Cassiopeiae”. Journal of the American Association of Variable Star Observers (JAAVSO) vol 20 (juni 1991): 35–38.