[vsnet-sequence 36] AY Lac sequence

[Taichi Kato <tkato>]

AY Lac sequence

From: "Bruce Sumner" <b.sumner@bom.gov.au>
Date: Mon, 18 Sep 2000 16:09:51 +1000
Subject: [vsnet-id 293] AY Lac sequence

For observers who might want to start observing this possible 
UG variable, here is a sequence.
Regards,
Bruce Sumner
----------------------
157  AY LACERTAE   (M/UG?)   Range: 14.5-<20p 
     Position:   22 22 23  +50 23 29    (GCVS)
     Magnitude: 

ID    RA (2000)    DEC       X    Y   N    V      ERR      B-V    ERR
 
a) Comparison star sequence
    
1   22 22 20.5  +50 24 36   -23   66  1  10.539  0.000   0.744  0.001 
2   22 21 55.8  +50 27 32  -259  242  1  11.079  0.001   0.125  0.001 
3   22 22 39.9  +50 21 00   161 -150  1  11.577  0.001   0.776  0.001 
4   22 22 31.4  +50 24 37    80   67  1  12.164  0.001   0.356  0.001 
5   22 22 16.6  +50 23 47   -62   17  1  12.950  0.001   0.470  0.001 
6   22 22 09.2  +50 19 22  -132 -248  1  13.520  0.002   0.432  0.003 
7   22 22 30.6  +50 24 28    72   58  1  13.948  0.002   0.756  0.004 
8   22 22 36.1  +50 20 17   126 -193  1  14.316  0.003   0.542  0.004 
9   22 22 26.8  +50 23 25    36   -5  3  14.722  0.005   0.723  0.004 
10  22 22 26.6  +50 23 54    34   24  3  15.005  0.006   0.982  0.004 
11  22 22 23.6  +50 23 26     5   -4  3  15.566  0.006   0.685  0.006 
12  22 22 23.8  +50 22 42     8  -48  3  16.273  0.011   0.652  0.016 
13  22 22 26.5  +50 23 41    34   11  2  16.590  0.000   0.873  0.009 
14  22 22 24.8  +50 23 30    17    0  2  17.345  0.008   0.846  0.006 
15  22 22 24.6  +50 23 44    15   14  2  17.863  0.008   1.049  0.011 
16  22 22 18.1  +50 23 08   -47  -22  2  18.352  0.011   0.975  0.018 
17  22 22 22.7  +50 23 54    -3   24  2  18.811  0.022   0.972  0.018 
18  22 22 22.2  +50 23 23    -8   -7  2  19.070  0.027   0.900  0.013 
  
b) Wide-colour extension for CCD calibration
 
    22 22 45.3  +50 24 01   213   31  1  12.317  0.001   0.292  0.001 
    22 22 24.5  +50 21 34    14 -116  1  12.333  0.001   1.453  0.002 
    22 22 46.1  +50 24 21   220   51  1  12.102  0.001   1.660  0.002 
    22 22 39.1  +50 20 30   155 -180  1  13.488  0.002   1.781  0.004 

Notes:

1. The first five bright stars in this sequence, all brighter than
magnitude 13, are saturated and their magnitudes are only 
approximate. They should be used for guidance only until their 
magnitudes are correctly determined.

2. This possible UG has been reclassified as a possible faint Mira 
stars in GCVS IV. However examination of five Schmidt plate images 
taken between 1952 and 1990 show no varying object in this field. 
It could still be a UG variable.

3. The DWS catalog of 1997 locates this variable about 25 arcsec 
north of the position given in GCVS IV. In fact the DWS position is 
very close to that of star 18 in this sequence, but star 18, at 
magnitude 18.8V, appears to be an ordinary field star. The exact 
position of AY Lac is thus currently unknown.

4. This sequnece is based on field photometry obtained by Arne 
Henden.

Bruce Sumner 
15 September 2000

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