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Re: v1413 Aql - Ready for Eclipse > Just a reminder - with all the talk of long period variables I have been > reading lately it reminded me that V1413 Aql is about ready to go into > eclipse. V1413 Aql has a period of 434 days. Using the Munari ephemeris I > calculate a mid point of the eclipse of 27 March 2003. The eclipse is about > 60 days wide so that means it is time to start observing the system now. I > haven't observed it yet this season but it is an early morning object. Based > on past eclipses, it should vary from around 13 to 15+ magnitude. Eclipsing > symbiotic systems aren't all that common so this would be a good one to > observe. It would be worth noting that the eclipse phenomenon in this object was discovered by an amateur astronomer, Minoru Wakuda (who also discovered a number of novae). The initial report by Wakuda appeared in VSOLJ Variable Star Bulletin 5, 17 (1988), on which Munari's ephemeris largely relied. When Wakuda noticed the variablity of this star, he thought it may be an R CrB-like star or a long-period eclipsing system, but neither of these possibilities naturally explained the long-term light curve. I was one of persons who noticed at the time that Wakuda's object can be identified with AS 338, a symbiotic star yet poorly known at the time. The light curve was marvellously explained by combination of a symbiotic outburst and eclipses. Recognizing the importance of the discovery, I readily recommended Wakuda-san to publish a paper. This story is what has been hidden in the history of the research of this object, but this illustrates the ability of outstanding amateur activity in variable star astrophysics. Such activities were already prominent in the 1980's, well before the present CCD era. But why I recognized AS 338 -- this was a perfectly chance recognition. A member of the VSOLJ, Noboru Hasegawa-san was deeply involved in observing symbiotic stars, and tried to observe *all* reachable symbiotic stars in Kenyon's catalog of symbiotic stars. It is again worth noting that this project was undertaken with a 10cm (4-inch) telescope. With an impetutous training, Hasegawa-san became able to visually track symbiotic stars down to 16-th mag with this telescope (a persuit for a better limiting magnitude was so zealous that he even once confessed: "I can *only* reach mag 16 with an aperture of 10cm"; we called his telescope a "miracle telescope"). He naturally created many charts of symbiotic stars for visual observation, and once asked me to check the field which he could not identify. That was AS 338, and I soon realized that he mistook the coordinates and plotted at a wrong position. Plotting at the correct coordinates, I immediately found the identity of AS 338 and Wakuda-san's peculiar variable star. If there had not been Hasegawa-san's chart error, the object may have been independently observed by different observers for a long time, and the clarification of the object's nature could have taken a longer time. Regards, Taichi Kato
Return to the Powerful Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
