[vsnet-alert 14560] Re: [VSS-members] AG Car Unsteady Decline Continues

[Peter F Williams]

Hi Sebastian,

Yes, the topic of different colour response by different observers is also
being discussed on the vss-members news group.

The monthly means are indicative only to show the irregular fading of AG
Car.  Here, my monthly means are derived from between 3 and 15 observations
according to the season and position/availability of the field.  Within some
months AG Car is also seen to vary by upto 0.6 magnitude and this too can
alter the monthly means as would be the case if the weather was cloudy
during these active times.

Our results show the same trend and seem to be internally consistent and I
think that is important.

In any case, AG Car is certainly fainter than for many years.  Good luck
with the weather!

Tks and regards

Peter Williams
Heathcote NSW



-----Original Message-----
From: Sebastián Otero [mailto:varsao at hotmail.com]
Sent: Friday, 11 May 2012 2:37 PM
To: Peter F Williams; vsnet alert
Subject: Re: [vsnet-alert 14558] Re: [VSS-members] AG Car Unsteady
DeclineContinues


Hi, Peter,

> The SDOR star AG Car has continued its irregular decline in recent months
> and based on my visual observations this star is currently near to its
> historically recorded minimum brightness based on the past 7 decades of
> data
> as displayed by the AAVSO light curve generator.

Yes, I noticed this fading too and that is also approaching the faintest
recorded magnitude.

The historical photometric minimum recorded was back in  with V= 8.11 on
May, 1987.

It is really weird how different response eyes can have.
I add the magnitudes I measured for the same dates to see how we are up to
1.2 mag. off !!!
I saw a 0.4 mag. fading while you observed a 1.4 mag. fading. Weird indeed!

I observe it with 7x50 binoculars that have a limiting magnitude around 8.5
or so on average nights in Buenos Aires and I never had trouble observing AG
Car even though it is fainter than normal.

> 2011
> Jan    7.56     7.44
> Feb    7.90    7.53
> Mar    7.67    7.63
> Apr    7.81     7.61
> May    7.94    7.63
> June   7.97     7.60
> July    8.15     7.59
> Aug    8.22
Sep -----------    7.58
Nov ----------    7.51
> Dec    7.73     7.52

> 2012
> Jan    7.77      7.52
> Feb    8.12     7.64
> Mar    9.00     7.76
> Apr    8.81      7.84
> May   9.00

My last observation was on April 18 due to bad weather and illness :( I hope
I'll be able to observe it this weekend.

Cheers,
Sebastian

-------------------------
Sebastian Otero
VSX Team
American Association of Variable Star Observers