[vsnet-newvar 1731] Re: [vsnet-campaign-unknown 151] Re: MisV1147 DSS Photometry

[DWest61506@aol.com]

In a message dated 12/8/2002 11:12:22 PM Central Standard Time, comet@aerith.net writes:

Dear Doug West,

First of all, thank you for your analysis on MisV1147.

> Plate       Date        Band        Mag     USNO-B
> DSS1        31 Oct  1953    R       13.59       13.30
> DSS1        31 Oct  1953    B       14.75       15.15
> DSS2        02 Sep  1989    B       14.69       14.71
> DSS2        03 Sep 1991     R       13.44       12.47
> DSS2        16 Aug 1993 I       13.15       13.24

Please also read my estimation:

  http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/chat5000/msg00447.html

which says the magnitude of MisV1147 as follows:

                     MisV1147
DSS1 R  1953 Oct. 31  14.36
DSS2 Bj 1989 Sept. 2  15.30
DSS2 R  1991 Sept. 3  13.29
DSS2 I  1993 Aug. 16  13.46

I do not know what caused the difference between us. But,

> Should I submit these observations to VSNET Observations?

please not right now, because it is not clear that which is correct.

Best regards,

--
Seiichi Yoshida
comet@aerith.net
http://vsnet.aerith.net/

Seiichi:
I had reviewed your magnitudes earlier and like you am a little puzzled by the fairly large differences.  Two reasons that come to mind are the difference in the number of comparison stars and the photometric aperture.  You used seven comparison stars and I used two.  Seven is better than two.  The question of photometric aperture is probably the most problematic.  Since these are non-Gaussian profiles this makes the choice of it very critical.  It would take some experimentation to come up with the correct answer.  How about an average of the number?

Plate       Date        Band        Mag     USNO-B      Avg West & Yoshida
DSS1        31 Oct  1953    R       13.59       13.30      13.98
DSS1        31 Oct  1953    B       14.75       15.15      14.75
DSS2        02 Sep  1989    B       14.69       14.71      15.00
DSS2        03 Sep 1991     R       13.44       12.47      13.37
DSS2        16 Aug 1993      I       13.15       13.24       13.30

Regards,
Doug West
http://hometown.aol.com/dwest61506/index.html

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp