<html><head></head><body><div style="color:#000; background-color:#fff; font-family:Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_ym19_1_1522832320354_4269">Nick,</div><div dir="ltr" id="yui_3_16_0_ym19_1_1522832320354_4186">In this latest version the settings will only allow filter band G to be set for Gaia DR1. This is a broadband filter according to the settings. Is this ok to use for reporting comet astrometry and for Comphot? Or should we still use UCAC4 and red in the filter settings?</div><div dir="ltr" id="yui_3_16_0_ym19_1_1522832320354_4268">Denis<br></div><div id="yui_3_16_0_ym19_1_1522832320354_4187"><span></span></div><div class="qtdSeparateBR" id="yui_3_16_0_ym19_1_1522832320354_4182"><br><br></div><div class="yahoo_quoted" id="yui_3_16_0_ym19_1_1522832320354_3974" style="display: block;"> <div style="font-family: Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_ym19_1_1522832320354_3973"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 16px;" id="yui_3_16_0_ym19_1_1522832320354_3972"> <div dir="ltr" id="yui_3_16_0_ym19_1_1522832320354_3971"> <font id="yui_3_16_0_ym19_1_1522832320354_4188" size="2" face="Arial"> <hr id="yui_3_16_0_ym19_1_1522832320354_4267" size="1"> <b><span style="font-weight:bold;">From:</span></b> Nick James <ndj@nickdjames.com><br> <b><span style="font-weight: bold;">To:</span></b> BAA Comets discussion list <comets-disc@lists.britastro.org> <br> <b><span style="font-weight: bold;">Sent:</span></b> Wednesday, 4 April 2018, 7:38<br> <b id="yui_3_16_0_ym19_1_1522832320354_4191"><span style="font-weight: bold;" id="yui_3_16_0_ym19_1_1522832320354_4190">Subject:</span></b> Re: [BAA Comets] Astrometrica now downloads from MPC server<br> </font> </div> <div class="y_msg_container" id="yui_3_16_0_ym19_1_1522832320354_4189"><br><div dir="ltr" id="yui_3_16_0_ym19_1_1522832320354_4192">Roger,<br clear="none"><br clear="none">Thanks. That would probably explain why my reduction used fewer <br clear="none">reference stars in the latest version.<br clear="none"><br clear="none">The change is not as significant as the last update where my Rc mags <br clear="none">changed by around 0.25:<br clear="none"><br clear="none"><a shape="rect" href="http://lists.britastro.org/pipermail/comets-disc/2017-March/000920.html" target="_blank" id="yui_3_16_0_ym19_1_1522832320354_4220">http://lists.britastro.org/pipermail/comets-disc/2017-March/000920.html</a><br clear="none"><br clear="none">People using Astrometrica for magnitudes should be aware of possible <br clear="none">changes between releases and should always quote the version number when <br clear="none">submitting data.<br clear="none"><br clear="none">Nick.<br clear="none"><br clear="none"><br clear="none"><br clear="none">On 03/04/2018 09:47, Roger Dymock wrote:<br clear="none">> Hi Peter, Nick,<br clear="none">> <br clear="none">> The improved colour correction may refer to the restricted (B-V) range i.e.0.5<(B-V)<1.2 as described in the soon to be published paper by Richard Miles and myself. Such a restriction would reduce the number of reference stars. Using UCAC4 will return Rc rather than r mags, the approximate formula for which is Rc=r-0.22.<br clear="none">> <br clear="none">> Astrometrica versions 420 and 424 returned r mags when using UCAC4. 431 returned Rc mags ditto and 433 introduced the (B-V) restriction mention above. Again this is explained in the aforementioned paper.<br clear="none">> <br clear="none">> Regards<br clear="none">> Roger Dymock<br clear="none">> Skype; rogerdymock67<br clear="none">> Tel; 023 92647986<br clear="none">> <br clear="none">> -----Original Message-----<br clear="none">> From: Comets-disc <<a shape="rect" ymailto="mailto:comets-disc-bounces@lists.britastro.org" href="mailto:comets-disc-bounces@lists.britastro.org">comets-disc-bounces@lists.britastro.org</a>> On Behalf Of Nick James<br clear="none">> Sent: 03 April 2018 07:09<br clear="none">> To: BAA Comets discussion list <<a shape="rect" ymailto="mailto:comets-disc@lists.britastro.org" href="mailto:comets-disc@lists.britastro.org">comets-disc@lists.britastro.org</a>><br clear="none">> Subject: Re: [BAA Comets] Astrometrica now downloads from MPC server<br clear="none">> <br clear="none">> Hi Peter,<br clear="none">> <br clear="none">> Thanks for drawing attention to this and to Herbert for continuing to suupport this essential program.<br clear="none">> <br clear="none">> Just one note. In Herbert's version history for the latest version<br clear="none">> (4.10.5.437) he says: "Improved colour correction for UCAC 4 and URAT 1". I'll try to find out exactly what this means since in the last change (to 4.10.0.431) there was a significant shift in UCAC-4 R magnitudes.<br clear="none">> <br clear="none">> I've checked UCAC-4 R magnitudes reducing a couple of frames for<br clear="none">> 4.10.0.431 and 4.10.5.437 and they seem to be the substantially the same although the number of reference stars used changed from one version to the other.<br clear="none">> <br clear="none">> Nick.<br clear="none">> <br clear="none">> On 02/04/2018 20:31, Peter Carson wrote:<br clear="none">>> Hi All,<br clear="none">>> For those not aware Herbert Raab of Astrometrica has just released an update to Astrometrica that now downloads the MPCOrb data directly from the MPC https server. See www.astrometrica.at/download.html For several months Astrometrica was unable to download directly from this secure server which did make it a bit of a pain to keep the orbital elements data base up to date. See an extract from Herbert’s notes below note:<br clear="none">>> All the best<br clear="none">>> Peter Carson<br clear="none">> _______________________________________________<br clear="none">> Comets-disc mailing list<br clear="none">> <a shape="rect" ymailto="mailto:Comets-disc@lists.britastro.org" href="mailto:Comets-disc@lists.britastro.org">Comets-disc@lists.britastro.org</a><br clear="none">> <a shape="rect" href="http://lists.britastro.org/mailman/listinfo/comets-disc" target="_blank">http://lists.britastro.org/mailman/listinfo/comets-disc</a><div class="yqt9853145489" id="yqtfd61917"><br clear="none">> <br clear="none">> _______________________________________________<br clear="none">> Comets-disc mailing list<br clear="none">> <a shape="rect" ymailto="mailto:Comets-disc@lists.britastro.org" href="mailto:Comets-disc@lists.britastro.org">Comets-disc@lists.britastro.org</a><br clear="none">> <a shape="rect" href="http://lists.britastro.org/mailman/listinfo/comets-disc" target="_blank">http://lists.britastro.org/mailman/listinfo/comets-disc</a><br clear="none">> <br clear="none"><br clear="none">_______________________________________________<br clear="none">Comets-disc mailing list<br clear="none"><a shape="rect" ymailto="mailto:Comets-disc@lists.britastro.org" href="mailto:Comets-disc@lists.britastro.org">Comets-disc@lists.britastro.org</a><br clear="none"><a shape="rect" href="http://lists.britastro.org/mailman/listinfo/comets-disc" target="_blank">http://lists.britastro.org/mailman/listinfo/comets-disc</a><br clear="none"></div></div><br><br></div> </div> </div> </div></div></body></html>