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[vsnet-chat 5346] Re: On UY Cen fading
- Date: Mon, 10 Jun 2002 16:53:58 +1000
- To: "Taichi Kato" <tkato@kusastro.kyoto-u.ac.jp>, <vsnet-campaign-rcb@ooruri.kusastro.kyoto-u.ac.jp>, <vsnet-chat@ooruri.kusastro.kyoto-u.ac.jp>, <vsnet-rcb@ooruri.kusastro.kyoto-u.ac.jp>
- From: "Peter F Williams" <pfwilliams@onaustralia.com.au>
- Subject: [vsnet-chat 5346] Re: On UY Cen fading
- Cc: <vsnet-gcvs@ooruri.kusastro.kyoto-u.ac.jp>
- Reply-To: <pfwilliams@onaustralia.com.au>
- Sender: owner-vsnet-chat@ooruri.kusastro.kyoto-u.ac.jp
Re UY Cen Decline
While I have not seen a copy of the BAA VSS Circular 112 mentioned, I
believe the reported magnitude therein is based largely on observations I
have sent to John Toone of the BAA VSS. This follows an initial report by
Colin Henshaw (BAA VSS) in February 2002 that UY Cen was the faintest he
had seen in many years.
My observations use a V magnitude sequence obtained from the vsnet web site
chart generator and have been obtained almost exclusively with 20x80mm
binoculars which clearly separate the magnitude 10.2 companion star
immediately to east (following) of the variable. Only one brightness
estimate has been made with the 30cm reflector to confirm the
identification of the variable. This showed the variable to be very red in
colour but this strong colouring in not evident through the binoculars.
Perhaps the difference in reported magnitudes relates to resolution of the
companion star or a different comparison sequence?
Listed here are my observations commencing from 2002 Feb 26UT through to
end of May in JD format (sorry!) extracted from the VSSOBS program of the
RASNZ VSS.
Regards
Peter Williams
Heathcote NSW
-131044 UY CEN 2452331.9486 9.80 11 Wy
-131044 UY CEN 2452339.9424 9.90 11 Wy
-131044 UY CEN 2452344.9750 9.90 11 Wy
-131044 UY CEN 2452348.0208 9.90 11 Wy
-131044 UY CEN 2452348.9236 9.90 11 Wy
-131044 UY CEN 2452349.9313 9.80 11 Wy
-131044 UY CEN 2452350.9375 9.80 11 Wy
-131044 UY CEN 2452351.9361 9.90 11 Wy
-131044 UY CEN 2452354.0035 9.90 11 Wy
-131044 UY CEN 2452355.9340 9.90 11 Wy
-131044 UY CEN 2452356.9007 9.90 11 Wy
-131044 UY CEN 2452356.9757 10.00 11v.red Wy
-131044 UY CEN 2452357.9646 9.90 11 Wy
-131044 UY CEN 2452365.9181 10.00 11 Wy
-131044 UY CEN 2452366.9375 9.90 11 Wy
-131044 UY CEN 2452367.9236 9.90 11 Wy
-131044 UY CEN 2452370.0069 9.90 11 Wy
-131044 UY CEN 2452370.9167 9.90 11 Wy
-131044 UY CEN 2452372.0729 9.90 11 Wy
-131044 UY CEN 2452373.9472 9.90 11 Wy
-131044 UY CEN 2452375.9708 9.90 11 Wy
-131044 UY CEN 2452377.0396 9.90 11 Wy
-131044 UY CEN 2452386.8736 9.90 11 Wy
-131044 UY CEN 2452388.0340 9.90 11 Wy
-131044 UY CEN 2452388.9840 9.80 11 Wy
-131044 UY CEN 2452394.8931 9.80 11 Wy
-131044 UY CEN 2452398.0049 9.80 11 Wy
-131044 UY CEN 2452398.9097 9.90 11 Wy
-131044 UY CEN 2452399.8875 9.90 11 Wy
-131044 UY CEN 2452400.9799 9.80 11 Wy
-131044 UY CEN 2452401.9097 9.90 11 Wy
-131044 UY CEN 2452402.9056 9.90 11 Wy
-131044 UY CEN 2452404.9792 9.80 11brighter?Wy
-131044 UY CEN 2452405.9611 9.80 11 Wy
-131044 UY CEN 2452406.8715 9.70 11 Wy
-131044 UY CEN 2452410.8868 9.70 11 Wy
-131044 UY CEN 2452411.9486 9.70 11 Wy
-131044 UY CEN 2452413.8722 9.80 11 Wy
-131044 UY CEN 2452414.9201 9.90 11 Wy
-131044 UY CEN 2452415.9854 9.90 11 Wy
-131044 UY CEN 2452416.8889 9.90 11 Wy
-131044 UY CEN 2452420.9042 9.90 11 Wy
-131044 UY CEN 2452425.9563 9.80 11 Wy
-131044 UY CEN 2452426.8868 9.90 11 Wy
----------
From: Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>
To: vsnet-campaign-rcb@ooruri.kusastro.kyoto-u.ac.jp;
vsnet-chat@ooruri.kusastro.kyoto-u.ac.jp;
vsnet-rcb@ooruri.kusastro.kyoto-u.ac.jp
Cc: vsnet-gcvs@ooruri.kusastro.kyoto-u.ac.jp
Subject: [vsnet-chat 5343] On UY Cen fading
Date: Friday, 7 June 2002 1:27
On UY Cen fading
According to BAA VSS Circular 112, 3 (J. Toone), UY Cen is reported to
have undergone a deep minimum (mag 10) in 2002 February to March. Such
a deep fading may have been compared to a RCB-type fading. Upon knowing
this information, I have checked the reports to VSNET.
YYYYMMDD(UT) mag observer
20010318.199 85 (Sebastian Otero)
20010410.000 85 (Sebastian Otero)
20010415.185 87 (Sebastian Otero)
20010513.000 88 (Sebastian Otero)
20010607.000 90 (Sebastian Otero)
20010628.000 91 (Sebastian Otero)
20010728.010 90 (Sebastian Otero)
20010807.981 90 (Sebastian Otero)
20010820.967 90 (Sebastian Otero)
20010823.971 90 (Sebastian Otero)
20020113.312 94 (Sebastian Otero)
20020202.276 90 (Sebastian Otero)
20020224.276 88 (Sebastian Otero)
20020224.280 89 (Cecilia Scalia)
20020324.212 86 (Sebastian Otero)
20020401.308 88 (Sebastian Otero)
20020406.103 86 (Sebastian Otero)
20020421.031 87 (Sebastian Otero)
20020421.033 89 (Cecilia Scalia)
These observation may suggests that the fading(?) already started in
2001, but the depth may be inconsistent with the report in BAA VSS
Circular??
Are we referring to a different star, or the object has recently changed
its
variation properties??
Identifications:
GSC7786.2428 131631.78 -444216.0 (2000.0) 8.12 0
USNO0450.15511308 131631.788 -444216.10 (2000.0) 8.1 99.9
IRAS13136-4426 131336.6 -442626 (1950.0)
F12=52.47 F25=20.89 F60=3.98 F100=1.32
VAR= 9 LRS=43
blue, 11micron (SiC) emission, strength=3
II: variable star with 'young' O-rich circumstellar shell
131631.9 -444209 (2000.0) CD-44.8539 7.5
131631.4 -444214 (2000.0) IRAS13136-4426 54.820 20.520 4.127 1.324 9%
4(LRS)
131631.4 -444214 (2000.0) SSC13136-4426 54.820 20.520 4.127 1.324
131631.6 -444214 (2000.0) HD115236 SC(Michigan)
131631.6 -444220 (2000.0) GCSS816 10 - - CENUY
131631.8 -444212 (2000.0) UBV_UYCen 6.70 2.73 4.06 .253 .100 - SC N=2 Nm=6
-
131631.8 -444214 (2000.0) SAO224021 99.9 7.1 K5p
131632.0 -444219 (2000.0) FSC13136-4426 55.710 20.700 3.817 1.249
131631.8 -444215 (2000.0) 685HV2 2.87 HIP064778 plx=1.66(1.04) (0.01 0.04)
U 6.54-7.11
131631.8 -444215 (2000.0) 702Vu 2.94 TYC7786.2428.1 plx=3.0(6.9) (0.01
0.05)
131631.7 -444215 (2000.0) 703 3.09 TYC2-7786.2428.1 (7.36 0.01) (10.99
0.05)
131631.8 -444214 (2000.0) CENUY SR 9.22 11.2 B - 114.6 - SC
131630.6 -444141 (2000.0) HD115236 30.0 30.0 K5p
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