GZN
Affiliation
American Association of Variable Star Observers (AAVSO)
Sun, 04/23/2017 - 21:52
Hi Andrew, Frank
It seems that U Draconis has developed, in the last months, a hump in the ascending light curve. Attached you can see some light curves and a phase plot where the hump is evident. Possible candidate to the " hump club" ?
Regards.
Alfredo Glez-Herrera (GZN)
File Upload
U Dra 250 days.png26.98 KB
U Dra 500 day.png29.88 KB
U Dra 1500 days.png48.59 KB
u Dra 5000 days.png77.1 KB
U Dra phase plot.png42.41 KB
Hi Alfredo, it looks real. I think we have to wait for the next max to see if it humps again.
Hi Hubert, i agree that more observations are needed, but remember that the humps not always are present on every cycle. A recommended mira to follow up.
Yes, that's true but from your curve it's clear that this time it's the first time that the hump is so obvious present.
I agree there is a clear hump on this cycle. I went back through all of the data points in AID for U DRA and beleive I see at least one more "hump" event for U DRA. I added it to our "Hump" list. It will be interesting if this star starts showing this behavior more often in the future.
Frank
And a faint maximum around JD 2455600
Hello Frank,
what is the date that you have found the other hump?
Hubert,
I see what appears to be "hump" or "stalling" behavior twice with U DRA with the 2 stalls beginning at @2440440 and @2440764. I wasn't having much luck finding any other examples for this star.
Thanks!
Frank
Hi Alfredo
That's a great pickup! There is also good consistency in the observations of this recent hump which adds to the confidence in the behaviour. Just goes to show all that LPV's can still surprise!
Regards
Andrew
Yes Andrew, we only need observations often and pay attention on the detail in the light curves.