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WZ Lyr in apparent standstill

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Joseph H. Ulowetz
Joseph H. Ulowetz's picture
WZ Lyr in apparent standstill

Hi everyone,

This might turn out to be nothing, but I wanted to point it out in case it's not.  I've been monitoring a few LPV's the last year and a half, and one of them is WZ Lyr, which is on the "Double Trouble" list because it has a nearby field star.

I don't think I have any problems with the field star, and I've seen this star go through an entire cycle and start a new one, all apparently normally. However, the current maximum is almost one magnitude brighter than last year, plus for about the last 2 weeks the brightness suddenly has remained constant, just slightly fainter than its maximum last month.  This is much different from the previous maximum in November 2015.

And just when this star seems to be doing something unusual, I'm about to lose it for the season.  I'll pick it up in January, but there is about a month when I can't observe it due to my local horizon.  If someone else can help observe it, it might be interesting.

I noticed another posting in this forum earlier this year about T UMi having an apparent standstill, so maybe WZ Lyr is another example of this?

 

Thanks,

-Joe

nmi
nmi's picture
Joe,

Joe,

I'm in Arizona, weather looks good, I'll take a look tonight.

Mike

Stan Walker
WZ Lyrae in apparent standstill

Hi Joe,

I read your note a I'm interested in Miras with double maxima which often also show a wide flat maximum.  WZ doesn't look that type but I was intrigued by some of the colour measures in the database.  The GCVS gives a M9e spectral type which should show as a quite red star - approaching B-V of 2.0.  But the rather sporadic measures vary between 0.5 and 1.5.  Peraps it has a blue companion as many of these do.  It would be interesting if someone could do V and B measures at 5% intervals in the light curve - every 15 to 20 days to see if it shows any evidence of such a companion - say in a flat or inverted B-V curve.  Unfortunately, from NZ's north it culinates at 8 degrees above my horizon.

Regards, Stan

Joseph H. Ulowetz
Joseph H. Ulowetz's picture
Stan,

Stan,

I don't have a B filter, only the V for photometric, but I do have RGB filters so I could try taking data in Tri-B.  It might not be as precise as a B filter, but I would think it would show if the color changes over time. If the color issue is still an open question next January, I'll add that to my program.

Thanks, -Joe

sfra
sfra's picture
WZ LYR

I'm imaging WZ LYR in all 4 filters as I type.  I'll transform the B and V results. 

Frank (SFRA)

Joseph H. Ulowetz
Joseph H. Ulowetz's picture
WZ Lyr still bright

I finally had a chance to check on this star again, and it is still at the same brightness now after a month.

-Joe

Joseph H. Ulowetz
Joseph H. Ulowetz's picture
WZ Lyr continues in standstill

I've been more successful at getting data during December than I had thought I would be able to, and I can now pick up WZ Lyr in the morning sky before dawn so I shouldn't have any interruptions going forward other than weather.

The star has stayed at about the same brightness for the past 2 months, and no indication of anything changing yet.

I talked to Arne about this, and he said that because LPV's have such long periods it can take decades to untangle multiple oscillation modes if there are any, so I should be prepared to be patient and continue to observe the star for the long term. So that's what I'm planning to do.

Happy New Year to everyone.

-Joe

 

Joseph H. Ulowetz
Joseph H. Ulowetz's picture
WZ Lyr appears to be fading now

My data last night shows it 0.2 mag fainter than a week ago, and it is down 0.4 mag from the end of December, so the standstill may be ending.

-Joe

 

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