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[vsnet-sequence 20] V1494 AQL - sequence
Here is the revised sequence for V1494 Aql. It covers the range from
10.0 to 17.5, and will suffice for the remaining fade to minimum of
this interesting nova. This sequence is based on field photometry
performed by Arne Henden, and contains accurate magnitudes of some of
the Tycho-2 stars in Bjorn Granslo's sequence. It is suggested that
all observers standarise to using this sequence as Bjorn's sequence
stars are beginning to show significant errors at the current
magnitude of the nova.
Bruce Sumner
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177 V1494 AQUILAE (N. AQL 1999 No. 2) Range: 3.6-~16)
Position: 19 23 05.36 +04 57 20.1 (J2000, Henden astrometry)
Magnitude: 10.195 B-V=0.400 (during outburst)
ID RA (2000) DEC X Y N V ERR B-V ERR
1 19 23 06.9 +05 06 13 23 533 1 10.072 0.02 0.289 0.02
2 19 22 43.4 +05 08 25 -328 665 1 10.515 0.02 0.734 0.02
3 19 22 20.0 +04 59 01 -678 101 1 10.736 0.02 0.624 0.02
4 19 22 27.9 +04 49 43 -561 -457 1 11.053 0.02 0.646 0.02
5 19 23 34.5 +04 55 03 435 -137 1 11.510 0.02 0.649 0.02
6 19 23 06.3 +04 53 36 13 -224 4 11.748 0.006 1.301 0.011
7 19 23 32.3 +04 54 50 402 -150 1 12.093 0.02 0.608 0.013
8 19 23 19.0 +05 08 47 203 687 1 12.351 0.02 0.395 0.02
9 19 23 19.7 +04 56 06 213 -74 3 12.601 0.008 1.363 0.011
10 19 23 40.1 +05 06 53 518 573 1 12.603 0.02 0.397 0.02
11 19 23 05.5 +05 00 03 1 163 4 12.767 0.021 1.506 0.017
12 19 22 52.2 +05 00 06 -198 166 3 12.934 0.010 1.299 0.016
13 19 23 06.4 +04 59 47 15 147 3 12.958 0.011 1.604 0.015
14 19 23 12.2 +04 52 46 101 -274 3 13.377 0.014 0.869 0.011
15 19 23 08.0 +04 58 02 38 42 5 13.759 0.025 1.030 0.016
16 19 23 05.2 +05 02 04 -3 284 5 13.859 0.014 0.990 0.022
17 19 23 19.7 +05 01 12 214 232 4 14.421 0.012 1.002 0.021
18 19 23 10.9 +05 00 09 82 169 4 14.632 0.012 0.977 0.006
19 19 22 57.3 +04 57 27 -121 7 4 14.760 0.008 1.030 0.014
20 19 22 57.3 +04 53 53 -120 -207 4 14.953 0.010 1.018 0.016
21 19 23 08.1 +04 56 55 40 -25 4 15.215 0.022 0.952 0.020
22 19 22 52.1 +04 54 17 -200 -183 4 15.581 0.014 1.011 0.019
23 19 23 14.0 +04 56 06 129 -74 4 15.927 0.011 1.372 0.035
24 19 23 12.9 +04 56 00 112 -80 4 16.246 0.018 1.056 0.007
25 19 23 04.7 +04 56 39 -10 -41 3 16.697 0.044 1.299 0.051
26 19 23 07.2 +04 56 14 27 -66 2 17.539 0.000 1.474 0.006
Notes:
1. This revised sequence replaces the sequence dated 22 July 2000.
Single night photometry now extends the sequence with some bright
stars up to magnitude 10.
2. A comprehensive and very carefully prepared sequence of bright
stars for use when the nova was bright, based on Tycho-2 data, was
issued by Granslo [vsnet-2018]. However he noted that his stars 14
(11.9/0.20) and 15 (12.5/0.2) are not to be relied on.
3. The accurate sequence presented here effectively replaces
Granslo's TYC-2 sequence below magnitude 10.0, and should be used
immediately, as the nova is currently about magnitude 10.7. Only two
of Granslo's TYC-2 comparison stars (12 and 14) fainter than
magnitude 10 do not now have accurate photometry, and should not be
used as comparison stars. The four stars below magnitude 10 that are
common to this and Granslo's sequence are:
Henden Granslo (TYC-2)
ID V B-V V B-V star
1 10.07 0.29 10.06 0.25 10
2 10.52 0.73 10.42 0.75 11
4 11.05 0.65 11.29 0.31 13
10 12.60 0.40 12.5 0.2 15
4. The faint part of the sequence given here is based on a
preliminary sequence prepared by Pejcha [vsnet-sequence 16], but with
many of his red stars replaced with stars that are much less red, and
additionally that are also generally closer to the nova than
Petjcha's stars.
5. Star 25 in this sequence was contaminated by the bright close-by
nova in the field photometry used to prepare the sequence. The
magnitudes and colours given here for star 25 were determined
independently from the raw field photometry to eliminate the
contamination.
Bruce Sumner
1 August 2000
vsnet-adm@kusastro.kyoto-u.ac.jp
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