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Error in sequence star DEC info for EW Lyr, #000-BCC-598

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ritzelj
Error in sequence star DEC info for EW Lyr, #000-BCC-598

I downloaded the XLM file for EW Lyr and my MPO software rejected the check star because of an invalid DEC arcsec value.

Below is a portion of the file that shows the error.

<star>EW Lyr</star>
<maglimit>16.0</maglimit>
<special/>
<auid>000-BCC-628</auid>
<fov>25.0</fov>
<dec>37:45:12.9</dec>
<title>EW Lyr</title>
<dss>False</dss>
<chartid>X15658FRA</chartid>
<image_uri>https://www.aavso.org/apps/vsp/chart/X15658FRA.png</image_uri>
<ra>18:33:15.61</ra>
-<photometry>
-<list-item>

<auid>000-BCC-598</auid>
<ra>18:32:33.36</ra>
<dec>37:47:60.0</dec>

The DEC can not be 60 arcsec or it should round up to the next arcmin value of 48.

John Ritzel RIZ

Sebastian Otero
Sebastian Otero's picture
Incorrect DEC values

Hi John,

I checked the star's position in VSD, the comparison star database (this is not a VSX issue since the comparison star is not variable), and it is given as 18 32 33.36 +37 48 00.0, so it is okay. However, as you say, in the photometry table the DEC appears as +37 47 60.0 (the non-rounded values is given as 37.79999924 so there may be a problem with rounding).
We need to look further into the question but in the meantime I have updated the position using UCAC3 coordinates that are +37 47 59.9 for the declination so the problem is solved (in this particular case).

Cheers,
Sebastian

ritzelj
Two more errors

Sebastian

I found two more stars used in Photometry tables with the same "rounding error" as you termed it:

#000-BBW-038

#000-BBD-021

Maybe this is more of an issue than we think?

John

 

Sebastian Otero
Sebastian Otero's picture
Corrected

John,
until we find a permanent solution I am correcting them individually with improved UCAC3 positions.
If you find some more, let us know.

Cheers,
Sebastian

ritzelj
Corrected

Sebastian

Thanks for fixing these, I will download them again.  I will let you know if I find anymore; I only passed these along to alert someone of the issue.

Thanks again

John R

ritzelj
More corrections

Sebastian

Hope you had good holidays.

I found Comp star 000-BBG-712 for W Eri also has the DEC seconds as 60.

Another item is that Comp star #105 is not shown on Chart X15739AIE, it is listed in the Photometric table for the chart though.

John R

Sebastian Otero
Sebastian Otero's picture
Corrections and chart labels

Hi John,

The comp 105 is plotted at the right edge of the chart. It is the star plotted above the W symbol. The problem is that, being at the edge, the magnitude label ended up outside the chart.
That should be something the software could manage I think (I mean, always including labels inside of the chart), but it seems to doesn't do it.
You can even barely see part of the "1" below and to the right of the star.

About the 137 comparison for W Eri with the DEC second problem I had to change 08 00.0 to 07 59.9 even when the position was 08 00.0 in all catalogues. It is not a meaningful difference at the level of precision we work on but I hope we can solve this problem the correct way in the near future.

Happy New Year,
Sebastian

ritzelj
Thanks for the corrects

GM Sebastian,

Thanks for the info, the MPO software will find the 105 star even though it is not shown on the plot; just wanted to pass it along.

I also edited the MPO files to reflect your correction to 137 also.

Thanks again and hoping for clear skies in the northeast of the US

John R

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