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Date: Mon, 5 Apr 93 12:25:21 PDT
From: alex%bkyim.hepnet@Lbl.Gov (ALEX FILIPPENKO, UC BERKELEY, 510-642-1813)
Subject: more stuff on SN 1993J...
4-5-93
Dear SN 1993J'ers:
We clearly need to be very careful about calibrating the photometric
measurements before drawing any final conclusions. This is going to be
tricky. Observers are encouraged to get accurate UBVRI photometry of all
comparison stars in the field of SN 1993J; we should eventually compare
results and end up with a final calibration.
Here are some more messages:
***
From Nick Suntzeff (CTIO):
If you give [people] the mags of the stars in the CCD field, they will
give you a mag with no problem. But this mag will probably be good to 0.05
mag or so in V, somewhat worse in B. This is because most CCD's have DQE's
that dive into the blue but a filter set made for S20's. This produces a
color term of 1.15-1.25 in B-V. If the SN is different by 0.50 in color
from the average field star in the CCD frame, the B phot will be wrong by
0.1 mag.
***
From Gerard de Vaucouleurs (Texas):
SN1993J Comparison Stars
Except for neglected color terms in the transformation to the
Johnson V system, the main source of scatter in the various
provisional magnitudes is in the adopted standards, often
star B = GSC 0928. The transformation from GSC V magnitudes
to Johnson V magnitudes published by Harold Corwin in IAU
Circular 5742 is
HGC V = 12.87 + 0.969(+/- 0.052)(GSC V - 12.43)
from an impartial l.s. line fit to GSC #0434,0928,1023,1031,1123.
These stars have all nearly the same color, <(B-V)> = + 0.54,
range 0.46-0.63. Stars #0224 (red) and #0308 (aberrant) are excluded.
Neglecting the barely significant scale coefficient, the mean
systematic difference between the two scales is HGCV-GSCV =
12.87 - 12.43 = + 0.44. This is close to the difference for
star B (11.90 - 11.42 = + 0.48).
A preliminary reduction to ~ 50 available estimates to the Johnson V
system (leaving still a large dispersion ~ 0.2 mag) suggests that
the V maximum was reached on JD9077.7 at V = 10.5, B-V = + 0.3,
with onset near JD9072.0.
G. de Vaucouleurs (gav@@astro.as.utexas.edu)
***
From Taichi Kato (Kyoto):
SN1993J photometric history
Updated list of observations obtained by Apr. 5.
This table is based on that sent from B. H. Granslo (Norway)
(bgranslo@astro.uio.no)
For photoelectric photometry with mentioned comparisons, I have tried
to reduce them using suggested photometric standards rather than GSC
magnitudes. Such data are denoted as "corrected mag".
Visual observations from Japan have also been reduced using V sequences
in "Supernova Search Chart" (designated as SEQ="TB").
I have not tried to reduce "unfiltered CCD magnitudes" to V magnitudes,
but left them as they are with designation "C". Prediscovery observation
on Mar. 28.30 UT is corrected according to G. de Vaucoulers using recent
photometric data on its comparison. Other CCD and visual magnitudes
without referred comparisons are left as they were.
Numerous data are included from Mark Kidger's table.
The compilation is only very preliminary and may contain errors.
Consult the original data sources for quantitative analysis.
Observations marked with * are communicated through this nova network.
color band: U,B,V Johnson system
R,I Kron-Cousins system unless notified
g,r Gunn g,r
mv visual (close to V)
p photographic (miscellaneous materials)
C unfiltered CCD
comparisons: TB Thompson-Bryan's "Supernova Search Chart" = V
+ recent photometry, assuming V=11.90 for star B.
TA "The Astronomer" sequence (system ?)
GP GSC photometric field = V
AC AAVSO chart = V?
--------------------------------------------------------------------------------
1985 01 21. 21 r Cohen, J. G. 1.5-m + CCD IAUC 5742
1985 01 21 21.9 g Cohen, J. G. 1.5-m + CCD IAUC 5742
1992 10 02. 20.0 R Salzer, J. et al. IAUC 5741
1993 02 24.687 <16.0 mv TB Kushida, R. Mail
1993 03 16.542 <15.0 mv TB Kushida, R. Mail
1993 03 16.90 20.0 R Prugniel, P. CCD serveral images IAUC 5742
1993 03 23.10 20.0 R Prugniel, P. CCD between two dates IAUC 5742
1993 03 21.667 <16.0 p TB Okamoto, Y. Mail
1993 03 25.60 <17 R van Driel, W. Kiso CCD IAUC 5737
1993 03 26.9 <14.0 mv Pujol, P.; IAUC 5731
Ripero, J.
1993 03 26.92 <14.5 mv ? (Kidger's table) ?
1993 03 27.91 <16.0 p Merlin, J.-C. Ektachrome 400 IAUC 5740
1993 03 28.30 13.4 C Neely, A. CCD IAUC 5740
corrected by G. de Vaucoulers
original mag = 13.8
1993 03 28.86 11.8 mv Garcia, F. 25-cm f/3.9 refl. IAUC 5731
DISCOVERY OBSERVATION
1993 03 28.89 11.6 C Rodriguez, D. 20-cm f/5 refl.+ AAVSO 169
ST-4 CCD
1993 03 29.01 11.3 mv Garcia, F. AAVSO 169
1993 03 29.019 11.2 C Ulfheden, P.; 15-cm refl.+ ST-6 CCD Mail
Hamberg, I.
1993 03 29.1 11.8 C Rodriguez CCD IAUC 5731
1993 03 29.18 11.7 C Neely, A. W. CCD, corrected mag. IAUC 5742
1993 03 29.691 10.3 p TB Hashimoto, Y. Fuji SG-400 Mail
1993 03 29.82 11.0 mv Ripero, J. AAVSO 169
1993 03 29.82 11.2 ? ? (Kidger's table) ?
1993 03 29.88 11.0 C Rodriguez, D. IAUC 5731
1993 03 29.88 11.3 mv Pujol, F. IAUC 5731
1993 03 29.95 11.1 mv Garcia, F. IAUC 5733
1993 03 30.006 11.0: C TB Solberg, R. 40.6-cm f/4.5 refl.+ Mail
ST-6 CCD
1993 03 30.1 11 mv Treffers, R. R. 0.8-m + CCD IAUC 5731
1993 03 30.25 10.2 V Hartwick,F.et al. 50-cm refl.+ CCD IAUC 5731
1993 03 30.538 10.4 mv TB Yamada, M. Mail
1993 03 30.82 10.0 ? ? (Kidger's table) ?
1993 03 30.845 10.3: mv TA Schmeer, P. 20.3-cm SCT IAUC 5733
1993 03 30.85 10.0 ? ? (Kidger's table) ?
1993 03 30.86 10.0 ? ? (Kidger's table) ?
1993 03 30.865 10.6 mv Poyner, G. 40-cm refl. Mail
1993 03 30.9 10.78 V *Unger, S. B-V=0.05 Nova
1993 03 30.9 10.83 B *Unger, S. B-V=0.05 Nova
1993 03 30.9 9.98 U *Unger, S. Nova
1993 03 30.9 10.60 I *Unger, S. Nova
1993 03 30.90 11.0 mv GP Midtskogen, O. 31.6-cm f/4.9 refl. Fax
1993 03 30.906 10.5 mv TB Schmeer, P. 20.3-cm SCT Mail
1993 03 30.91 10.0 ? ? (Kidger's table) ?
1993 03 30.916 10.6 mv Poyner, G. 40-cm refl. Mail
1993 03 30.93 10.5 mv TA Bengtsson, H. 15-cm refl. Mail
1993 03 30.94 10.5 mv Shanklin, J. D. IAUC 5736
1993 03 30.989 10.6 mv Poyner, G. 40-cm refl. Mail
1993 03 31.00 11.05 B Prugniel, P. 0.8-m + CCD, B-R=+0.3 IAUC 5736
1993 03 31.00 10.75 R Prugniel, P. (0.8-m, CCD) B-R=+0.3 IAUC 5736
1993 03 31.087 10.0 mv S Moore, D. 20-cm SCT, class 2 News
1993 03 31.1 10 mv Kohl, R. Independent discovery IAUC 5736
1993 03 31.1 10.21 U *Unger, S. Nova
1993 03 31.1 10.85 V *Unger, S. B-V=0.10 Nova
1993 03 31.1 10.95 B *Unger, S. B-V=0.10 Nova
1993 03 31.1 10.74 R *Unger, S. Nova
1993 03 31.1 10.62 I *Unger, S. Nova
1993 03 31.13 10.6 mv GP Midtskogen, O. 31.6-cm refl. Fax
1993 03 31.13 10.5 mv Caimciolo, F. IAUC 5736
1993 03 31.17 10.79 V Balonek, T. J. Corrected, CCD IAUC 5746
et al.
1993 03 31.2 10.7 R Salzer, J. et al. IAUC 5741
1993 03 31.2 10.60 K
1993 03 31.21 10.81 V Neely, A. W. Corrected mag. IAUC 5742
1993 03 31.21 10.4 C Neely,A.W. CCD, corrected mag. IAUC 5742
1993 03 31.26 10.82 V Balonek, T. J. Corrected, CCD IAUC 5746
et al.
1993 03 31.424 10.5 mv TB Yamada, M. Mail
1993 03 31.440 10.5 mv TB Yamada, M. Mail
1993 03 31.576 10.5 mv TB Kato, T. Mail
1993 03 31.84 10.5 mv Zanotta, M. V.; IAUC 5737
Pesci, S .
1993 03 31.88 10.5 ? ? (Kidger's table) ?
1993 03 31.89 10.6 ? ? (Kidger's table) ?
1993 03 31.9 10.63 U *Unger, S. Nova
1993 03 31.9 11.06 V *Unger, S. B-V=0.22 Nova
1993 03 31.9 11.28 B *Unger, S. B-V=0.22 Nova
1993 03 31.9 10.85 R *Unger, S. Nova
1993 03 31.9 10.66 I *Unger, S. Nova
1993 03 31.93 10.5 ? ? (Kidger's table) ?
1993 03 31.961 10.97 V Hanzl, D. B-V=+0.33 IAUC 5742
1993 03 31.961 11.30 B Hanzl, D. B-V=+0.33 IAUC 5742
1993 03 31.972 10.94 V Sostero, G. et al. B-V=+0.37 IAUC 5741
1993 03 31.972 11.31 B Sostero, G. et al. B-V=+0.37 IAUC 5741
1993 04 01.00 11.40 B Prugniel, P. (CCD) B-R=+0.45 IAUC 5741
1993 04 01.00 10.95 R Prugniel, P. (CCD) B-R=+0.45 IAUC 5741
1993 04 01.020 10.90 V Sostero, G. et al. B-V=+0.40 IAUC sub
1993 04 01.020 11.30 B Sostero, G. et al. B-V=+0.40 IAUC sub
1993 04 01.055 10.4 mv Beauchamp, D. 20.3-cm SCT. Class 2 Mail
1993 04 01.08 10.7 mv Schmeer, P. IAUC 5740
1993 04 01.18 11.08 V Neely, A. W. Corrected mag. IAUC 5742
1993 04 01.18 11.0 C Neely, A. W. CCD, corrected mag. IAUC 5742
1993 04 01.21 11.07 V Balonek, T. J. Corrected, CCD IAUC 5746
et al.
1993 04 01.40 11.13 V Balonek, T. J. Corrected, CCD IAUC 5746
et al.
1993 04 01.453 10.5 mv TB Takahashi, S. Mail
1993 04 01.465 10.5 mv TB Iida, M. Mail
1993 04 01.480 10.6 mv Momose ?
1993 04 01.538 10.4 mv TB Kato, T. Mail
1993 04 01.58 10.8 p TB Kushida 40-cm +Fuji SuperG400 Mail
1993 04 01.604 11.0 mv TB Kiyota, S. Mail
1993 04 01.622 10.4 mv TB Watanabe, Y. Mail
1993 04 01.632 11.2 mv Shioi, H. Mail
1993 04 01.633 10.5 p TB Kushida, Y. Tri-X, no filter Mail
1993 04 01.660 11.21 V Okyudo, M. CCD Mail
1993 04 01.726 11.0 mv TB Watanabe, T. Mail
1993 04 01.750 11.0 mv TB Koyama, H. Mail
1993 04 01.785 10.8 p TB Koyama, H. GX 3200, no filter Mail
1993 04 01.795 10.5 mv TB Hirosawa, K. Mail
1993 04 01.803 10.7 mv AC Schmeer, P. 20.3-cm SCT Mail
1993 04 01.81 10.5 mv Vanmunster, T. IAUC 5740
1993 04 01.816 11.19 V Hanzl, D. B-V=0.32 IAUC 5742
1993 04 01.84 10.4 ? ? (Kidger's table) ?
1993 04 01.86 11.32 V Mikolajewski, M. B-V=0.26, V-R=0.37 IAUC 5742
V-I=0.37
1993 04 01.86 11.58 B Mikolajewski, M. B-V=0.26, V-R=0.37 IAUC 5742
1993 04 01.86 10.95 R Mikolajewski, M. B-V=0.26, V-R=0.37 IAUC 5742
1993 04 01.86 10.95 I Mikolajewski, M. B-V=0.26, V-R=0.37 IAUC 5742
1993 04 01.87 10.5 ? ? (Kidger's table) ?
1993 04 01.87 10.5 ? ? (Kidger's table) ?
1993 04 01.87 10.6 ? ? (Kidger's table) ?
1993 04 01.9 11.03 U *Unger, S. Nova
1993 04 01.9 11.31 V *Unger, S. B-V=0.29 Nova
1993 04 01.9 11.60 B *Unger, S. B-V=0.29 Nova
1993 04 01.9 11.06 R *Unger, S. Nova
1993 04 01.9 10.85 I *Unger, S. Nova
1993 04 02.042 10.6 mv TB Kratz, D. 20-cm f/3.5 refl. News
1993 04 02.1 11.24 U *Unger, S. Nova
1993 04 02.1 11.41 V *Unger, S. B-V=0.32 Nova
1993 04 02.1 11.73 B *Unger, S. B-V=0.32 Nova
1993 04 02.1 11.15 R *Unger, S. Nova
1993 04 02.1 10.91 I *Unger, S. Nova
1993 04 02.13 11.37 V Balonek, T. J. Corrected, CCD IAUC 5746
et al.
1993 04 02.15 11.45 V Neely, A. W. Corrected mag. IAUC 5742
1993 04 02.15 11.5 C Neely, A. W. CCD, corrected mag. IAUC 5742
1993 04 02.22 11.39 V Balonek, T. J. Corrected, CCD IAUC 5746
et al.
1993 04 02.37 11.45 V Balonek, T. J. Corrected, CCD IAUC 5746
et al.
1993 04 02.439 11.0 mv TB Yamada, M. Mail
1993 04 02.453 10.9 mv TB Takahashi, S. Mail
1993 04 02.494 11.50 V Kato, T. (CCD) CCD Mail
1993 04 02.611 11.78 B Kato, T. (CCD) CCD Mail
1993 04 02.637 11.08 I Kato, T. (CCD) CCD Mail
1993 04 02.585 11.1 mv TB Watanabe, M. Mail
1993 04 02.608 11.5 mv TB Sakuma, S. Mail
1993 04 02.716 10.6 mv TB Abe, S. Mail
1993 04 02.843 11.3 mv Poyner, G. 40-cm refl. Mail
1993 04 02.867 11.3 mv TB Granslo, B. H. 20.3-cm SCT, 123x,
class 2 (hazy sky)
1993 04 02.95 11.5 mv TA Bengtsson, H. 15-cm refl. Mail
1993 04 03.011 11.2 mv TB Granslo, B. H. 20.3-cm SCT, 123x,
class 2 (hazy sky)
1993 04 03.299 11.75 V GS Robosope 40.6-cm refl.+512x512 Mail
(Univ. Indiana) Tektronix CCD
1993 04 03.342 11.78 V GS Robosope Mail
1993 04 03.369 11.76 V GS Robosope Mail
1993 04 03.385 11.77 V GS Robosope Mail
1993 04 03.448 11.3 mv TB Takahashi, S. Mail
1993 04 03.555 11.76 V Kato, Taichi Mail
1993 04 03.561 12.09 B Kato, Taichi Mail
1993 04 03.574 11.15 I Kato, Taichi Mail
1993 04 03.574 11.5 mv TB Takahashi, S. Mail
1993 04 03.66 11.8 mv TB Kushida, R. Mail
1993 04 03.68 11.9 mv TB Kushida, Y.
1993 04 03.831 11.0 mv TB Dahle, H. 20.3-cm SCT, 200x,
AAVSO mags, class 1
1993 04 03.837 11.2 mv TB Dahle, H. 20.3-cm SCT, 200x;
Sandage mags.,class 2
1993 04 03.862 11.4 mv TA Westlund, M. 20.3-cm SCT Mail
1993 04 04.029 11.6 mv TB Schmeer, P. 20.3-cm SCT Mail
1993 04 04.083 10.8: mv TB Kratz, D. 20-cm f/3.5 refl. News
1993 04 05.120 11.9 mv TB Schmeer, P. 20.3-cm SCT Mail
1993 04 05.15 11.6 mv TB Levy, S. 20.3-cm SCT, 133x News
(Univ. Minnesota)
1993 04 05.431 11.8 mv TB Takahashi, S. Mail
1993 04 05.437 12.2 mv TB Kiyota, S.
1993 04 05.444 12.0 mv TB Yamada, M.
1993 04 05.517 12.0 mv TB Kushida, Y.
1993 04 05.517 12.0 mv TB Kushida, R.
1993 04 05.566 12.1 mv TB Watanabe, Y.
1993 04 05.684 12.0 mv TB Watanabe, S.
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