Változócsillagászati újdonságok
 
Egy új blazár: S5 0716+71

V-R transzformáció a sötéthez adaptálódott ill. nem adaptálódott szemhez...

Halványodik az R CrB!

Nóvagyanús csillag a Kígyótartóban
Új változó az NGC 4013-nél
VSNET térképek
Szupernóva honlapok
VSNET



Egy új blazár: S5 0716+71

Date: Sat, 7 Nov 1998 18:53:52 -0700
From: bas@lowell.edu (Brian Skiff)
Subject: [vsnet-chat 1448] Re: (fwd) S5 0716+71 chart (Poyner)
 

     Below is the complete sequence for the S5 0716+71 field, as published by Villata et al. (1998 Astron. & Astrophys. Suppl. 130, 305).  Star coordinates are from the GSC.  The full paper, including charts, can be obtained on-line, starting at:

http://www.edpsciences.com/articles/astro/abs/1998/11/ads1482/ads1482.html

...where html, PDF, and PostScript files are linked.
 

Name                  RA  (2000)  Dec         GSC       V    B-V   V-R
S5 0716+714 1       7 22 36.4  +71 22 49   4368-0870  10.99  0.55  0.36
S5 0716+714 2       7 21 33.3  +71 19 21   4368-1025  11.46  0.56  0.34
S5 0716+714 3       7 21 52.3  +71 18 18   4368-0930  12.43  0.61  0.37
S5 0716+714 4       7 22 18.0  +71 23 35   4368-0846  13.19  0.47  0.30
S5 0716+714 5       7 21 54.3  +71 19 21   4368-0899  13.55  0.60  0.37
S5 0716+714 6       7 22 12.6  +71 21 15   4368-1196  13.63  0.61  0.37
S5 0716+714 7       7 21 14.0  +71 17 10   4368-0975  13.74  0.81  0.42
S5 0716+714 8       7 22 28.2  +71 17 38   4368-1070  14.10  0.60  0.31
 

\Brian



Halványodik az R CrB!

Mint azt a hazai és külföldi észlelések mutatják, kb. másfél év után ismét halványodik a R coronae Borealis.
 

A R CrB térképe letölthetõ:

R CrB "a" térkép
R CrB "b" térkép
 


V-R transzformáció a sötéthez adaptálódott ill. nem adaptálódott szemhez...

From: aah@nofs.navy.mil
Date: Mon, 5 Oct 1998 21:09:42 -0700
To: vsnet-chat@kusastro.kyoto-u.ac.jp
Subject: [vsnet-chat 1356] Re: Graham E-region standards
 

Berto Monard asked about transformations from (V-R) to visual magnitudes.  I did some
calculations awhile back for Janet Mattei using the CIE response curves for photopic
(bright adapted eye) and scotopic (dark adapted eye) eyes, along with Johnson/Cousins
curves and the Gunn-Stryker spectrophotometric atlas.  The results were:

     P = V -0.001 -0.066(B-V)       = V -0.010 -0.073(V-R)
     S = V -0.006 +0.382(B-V)       = V +0.031 +0.448(V-R)
 
These relations are reasonably good for colors < 1.5.

Whose eyes are scotopic and whose are photopic?  Beats me, and I certainly don't want
to get into any arguments -- I'm not any kind of expert here.  The normally quoted
transformation is v = V +0.2(B-V), which falls inbetween these relations.  The main
point is that (B-V) and (V-R) both give similar transformations, and so both should
be ok for determining visual magnitudes from photometric magnitudes/colors.  The (V-R)
fit is somewhat worse since you are extrapolating to the bluer visual magnitudes (especially
the bluer dark adapted eye) rather than bracketing them, but R is certainly easier to
measure with most amateur CCDs than is B.

Arne