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U Dra has developed a hump

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
hhu
Affiliation
Vereniging Voor Sterrenkunde, Werkgroep Veranderlijke Sterren (Belgium) (VVS)
Thu, 04/27/2017 - 16:34
Hump

Hi Alfredo, it looks real. I think we have to wait for the next max to see if it humps again. 

GZN
Affiliation
American Association of Variable Star Observers (AAVSO)
Thu, 04/27/2017 - 17:27
Hump

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.

hhu
Affiliation
Vereniging Voor Sterrenkunde, Werkgroep Veranderlijke Sterren (Belgium) (VVS)
Thu, 04/27/2017 - 17:37
Obvious present

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.

sfra
Affiliation
American Association of Variable Star Observers (AAVSO)
Thu, 04/27/2017 - 21:26
Hump on U DRA

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

sfra
Affiliation
American Association of Variable Star Observers (AAVSO)
Tue, 05/23/2017 - 17:30
When?

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

Andrew Pearce
Affiliation
American Association of Variable Star Observers (AAVSO)
Sat, 04/29/2017 - 03:04
U Dra

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