[vsnet-obs 41365] [vsnet-obs] SN Data: Correction vsnet-obs 41251

["Jean marie Llapasset" <jean-marie.llapasset@wanadoo.fr>]

Please correct following observation in [vsnet-obs 4125 ]
SN2002er 20020906.869 139CR Nic

Should be read:

SN2002er 20020906.869 142CR Nic
US 152 G 3.3" 120s 45°
http://vsnet.astrosurf.com/snweb/2002/02er/images/02erNI_C200209062052.htm

A large discrepancy appeared between the measures published by J. Nicolas and J.
B. de Vanssay, members of the groupe CCD-Web
(http://fr.groups.yahoo.com/group/CCD-Web/).

As members of the group always report the star they used as reference, it
appeared that J. B. de Vanssay used the star referenced as 143R on O. Trondall
image, while J. Nicolas used the star referenced 150R and, in a further study,
J. C. Pelle ( mailto:jcpelle@mail.pf ), taking into account color term and
magnitude term in the USNO magnitudes, concluded that both stars where in error
with a total discrepancy of 0.57 mag.

J. C. Pelle proposes the following corrections

OT 143 -0.20 mag i.e. 14.10
OT 150 +0.27 mag i.e. 15.27

This accounts for a 0.47 mag difference.

J. C. Pelle explains the remaining 0.10 magnitude as follow

Color term	 +0.025 mag
Magnitude term	 +0.077 mag


J. C. Pelle also recommends using as reference the USNO star at the East of the
SN

    RA         DC    Mag_B   Mag_R   V-R   Dist(°)
17 11 43.4 +08 00 33 16.30B  15.20R +0.40   0.057

which appears to have a magnitude in good accordance with the remaining of the
field.


Software SNWeb provided by Jean-Claude PELLE ( jcpelle@mail.pf )

Jean-Marie LLAPASSET
Obs 635 Perpignan (France)
http://perso.wanadoo.fr/jm.llapasset
http://vsnet.astrosurf.com/snweb/

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