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Y Del

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vega82's picture
Y Del



Добрый день. Может ли кто-нибудь сказать мне, что интересно о долгосрочной звезде y Del?



vega82's picture


Good afternoon. Can anyone tell me what is interesting about the long-period star Y Del?

HRHA's picture
Y Del

Hi vega82,

Not sure about this star, not much literature on it, however looking at the AID light curve, observations seem to go back a long way. It also is interesting that the more recent V band (CCD filter?) does not match up to the long-term visual observations with regard to magnitudes.  And then looking at the other filtered data (on a weekly average of observations) show really a lot of variability in the magnitudes. Perhaps some knows why the V band in these data have such a different magnitude than the historic visual observations? 



Eric Dose
Eric Dose's picture
Y Del Visual obs do match V & TG, except Visual outliers

Recent visual observations do rather closely match CCD V-filter observations (many of them mine), and TG obs as well. This is aside from a few outlier visual reports at 14 mag, occuring only when the target fainter than that: these errors almost certainly result from mistakenly observing another Vmag 14 star 34 arcseconds away when Y Del is much fainter.

For a Mira, Y Del can brighten extremely rapidly--often 1-1.5 magnitudes per week. This would make me hesitate to apply weekly averages to it.

edit: Y Del does seem to be brightening over the years. This is what caused me to start observing it--that, plus its being in Percy's List.

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