I have not corrected for the heliocentric redshift in these data.

**************************************************
Perr must stand for photon noise error.
I assume no reddening correction either

NGC 628 = M74
heliocentric velocity
from lines in sn spectra  +631 km/s  iauc 7822 S. Smartt & P. Meikle
from Leda  in radio       +656 km/s
from Leda  in optical     +639 km/s
from Leda  mean           +656 km/s

Foreground extinction in
B from Leda/Schlegel   0.30
E(B-V)=.30/4           0.075
E(B-V)=.30/4.1         0.073  See Cardelli p. 249
Paolo E(B-V)           0.08


**********************************************

Polarization  2002 feb 8

lambda(A), q(%), u(%), P(%), theta(deg), Perr.

END:
  5121.86377  0.41960001
  5402.63281  0.674899995
  5569.5  0.751699984
  5744.99316  0.427599996
  5884.21289  0.734300017
  5983.55518  0.738699973
  6079.13916  0.630500019
  6167.88477  0.577799976
  6240.07715  0.573800027
  6307.79883  0.584100008
  6375.1748  0.68629998
  6442.53906  0.625999987
  6510.11523  0.712100029
  6577.08105  0.683799982
  6644.73877  0.522199988
  6711.979  0.684099972
  6779.68799  0.881799996
  6852.43604  0.888700008
  6929.81689  0.736899972
  6996.14795  0.925899982
  7056.90283  0.740199983
  7110.95801  0.707899988
  7164.8252  0.864799976
  7219.06494  0.764100015
  7265.9751  0.612600029
  7306.38623  0.827899992
  7346.68115  0.863099992
  7393.36084  0.699100018
  7453.45117  1.08169997
  7527.29492  0.894699991
  7638.97314  0.444700003
  7718.26416  0.782000005
  7772.17822  0.459199995
  7826.00098  0.705500007
  7879.68604  0.716300011
  7940.12012  0.958400011
  8013.5918  1.32860005
  8106.47412  1.96879995
  8225.24023  1.44410002
  8329.55469  0.590200007
  8394.82129  0.527899981
  8441.2168  0.422899991
  8481.52344  0.618700027
  8514.94727  0.553900003
  8541.8584  0.556800008
  8568.7998  0.444799989
  8595.65039  0.496699989
  8622.61523  0.552699983
  8649.5752  0.53490001
  8676.56543  0.524800003
  8703.53418  0.349299997
  8730.45215  0.623000026
  8757.42188  0.451200008
  8790.76367  0.3926
  8831.62988  0.483500004
  8872.14453  0.403800011
  8912.52734  0.298500001
  8959.26172  0.562900007
  9013.99805  0.4287