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[vsnet-ecl 342] DE DRA with HIP mags
>Date: Thu, 19 Apr 2001 23:13:48 -0700
>From: Thom Gandet <tgandet@mindspring.com>
>To: Kari Tikkanen <ktikkane@mail.student.oulu.fi>
>CC: vsnet-chat@kusastro.kyoto-u.ac.jp,
> "Otero, Sebastian" <varsao@fullzero.com.ar>,
> vsnet-ecl@kusastro.kyoto-u.ac.jp
>Subject: Re: DE Dra confusion ?
> Predicted Minima Hipparcos Minimum Probable
> Min I: Min II: Minimum
> 2448231.812 2448229.385 2448231.55 I
> " " 8231.565 I
> 8316.582 8319.453 8317.112 I
> 8348.371 8351.242 8349.114 I
> 8438.439 8441.310 8438.858 I
>
> The first two Hipparcos observations were taken from a posting by
>Sebastian [vsnet-chat 4192] in which he attributed them to DE Dra.
>The subject on the header was DK Cam, so perhaps those observations
>are really of DK Cam.
Dear Thom,
They are from DE DRA but I put some doubts on some of those
and you'll see why I doubt when You look Appendix I put down below
>(By the way, why are two magnitudes
>given for each time in the "observed mags" column? Did you observe
>through filters?)
No filters.
Visual independent observations by Argelander style estimation.
v-e, v-b. I mean compared to star e and and compared to star b.
> Observed times Min. I O-C Min. II O-C
> JD JD (days) JD (days)
>
> 2451554.141 2451553.728 +0.413 2451556.599 -2.458
> 1554.325 " +0.597 " -2.274
>
> 1555.143 " +1.415 " -1.456
>
> 1752.406 1749.758 +2.648 1752.629 -0.223
> 1752.451 " " -0.178
>
> 1760.385* 1760.354 +0.031 1757.927 +2.458
> 1760.434 " +0.080 " +2.507
>
> 1776.317* 1776.219 +0.098 1773.822 +2.495
>
>
> It looks like you observed Min. I on JD 2451760 and JD 2451776, and
>Min II just starting on JD 2451752. Your observation on JD 2451555
>is especially interesting and valuable because it occurs at very
>nearly the spectroscopically predicted time of quadrature, so DE Dra
>should have been very close to maximum then. Congratulations on
>both counts!
Thanks.
> If I may offer a word of caution: periodogram analysis doesn't
>provide very meaningful results on small data sets which cover only a
Yes,
I doubt that it is my comp star b or some star nearby that varies..
With Best Regards,
Kari.
---Appendix--
Hipparcos magnitudes of DE DRA (HIP100221)
HT1 |HT2 |HT3 |HT4
7889.30504| 5.7239|0.010| 1
7889.31934| 5.6964|0.004| 1
7948.21209| 5.7025|0.006| 0
7948.22639| 5.7218|0.007| 0
7975.06160| 5.7062|0.004| 25
7975.22509| 5.7030|0.005| 0
7975.23940| 5.7099|0.006| 0
8007.21262| 5.7055|0.005| 1
8007.22694| 5.7077|0.005| 1
8097.83412| 5.7001|0.005| 0
8097.84847| 5.6990|0.005| 0
8097.92304| 5.7045|0.005| 0
8097.93736| 5.7033|0.005| 0
8119.96118| 5.7040|0.005| 0
8119.97550| 5.7068|0.006| 0
8155.49638| 5.7039|0.005| 0
8155.51071| 5.7024|0.005| 0
8155.58526| 5.6997|0.004| 0
8155.59961| 5.6995|0.005| 0
8155.68849| 5.7305|0.023| 2
8175.13534| 5.7034|0.005| 0
8175.14966| 5.7105|0.004| 0
8175.22422| 5.7118|0.004| 0
8175.23857| 5.7035|0.005| 0
8209.17291| 5.7081|0.006| 0
8209.24745| 5.7148|0.006| 0
8209.26180| 5.7039|0.007| 2
8209.33636| 5.7026|0.006| 0
8209.35071| 5.7096|0.005| 0
8231.37269| 5.7098|0.005| 0
8231.38703| 5.7100|0.004| 0
8231.46160| 5.7046|0.005| 0
8231.47591| 5.7147|0.005| 0
8231.55046| 5.7002|0.005| 0
8231.56480| 5.7006|0.006| 0
8261.84547| 5.7068|0.004| 0
8261.85979| 5.7095|0.004| 0
8261.94868| 5.6980|0.004| 0
8289.56705| 5.7095|0.005| 2
8289.58134| 5.7075|0.007| 2
8289.65592| 5.7040|0.005| 0
8289.67023| 5.7070|0.005| 0
8317.03762| 5.7119|0.005| 0
8317.11221| 5.7057|0.006| 0
8349.01036| 5.7041|0.006| 0
8349.02470| 5.7048|0.007| 0
8349.09923| 5.6976|0.005| 0
8349.11357| 5.7007|0.007| 0
8377.00107| 5.7058|0.006| 0
8377.01539| 5.7052|0.005| 0
8406.87116| 5.7032|0.005| 0
8406.94573| 5.7151|0.007| 0
8406.96002| 5.7063|0.006| 0
8438.84349| 5.6872|0.008| 0
8438.85783| 5.7120|0.006| 0
8463.10274| 5.7097|0.006| 1
8463.11707| 5.7070|0.007| 0
8463.19164| 5.7016|0.006| 0
8463.20593| 5.6989|0.006| 0
8498.20857| 5.6920|0.006| 0
8498.28316| 5.6979|0.005| 0
8498.29749| 5.7131|0.005| 0
8498.37203| 5.7058|0.007| 0
8518.27776| 5.7033|0.005| 0
8518.29205| 5.7091|0.005| 0
8518.36664| 5.7045|0.007| 2
8553.30999| 5.7067|0.005| 0
8553.32436| 5.7038|0.005| 0
8553.39891| 5.6974|0.005| 0
8553.41323| 5.7059|0.004| 0
8574.01444| 5.7082|0.005| 0
8574.02879| 5.7031|0.005| 0
8605.92137| 5.7003|0.005| 0
8605.99591| 5.7065|0.006| 0
8606.01025| 5.7073|0.006| 0
8606.08481| 5.7035|0.007| 0
8606.09917| 5.7068|0.005| 0
8631.31885| 5.7042|0.007| 0
8631.33318| 5.7055|0.006| 0
8631.40773| 5.7020|0.006| 0
8631.42207| 5.7046|0.005| 0
8659.66202| 5.7060|0.005| 0
8659.75092| 5.7062|0.009| 0
8659.76525| 5.7075|0.006| 0
8717.69890| 5.7045|0.006| 0
8717.77349| 5.7001|0.005| 0
8717.78781| 5.7163|0.007| 0
8749.22812| 5.6991|0.005| 0
8749.24242| 5.7105|0.007| 0
8749.31699| 5.7035|0.005| 0
8749.33131| 5.7091|0.007| 0
8749.40588| 5.7130|0.006| 0
8779.43885| 5.7231|0.006| 1
8779.45321| 5.7038|0.005| 0
8779.52780| 5.7071|0.004| 0
8779.54210| 5.7129|0.006| 0
8806.09672| 5.7066|0.005| 0
8806.11102| 5.7054|0.007| 0
8806.18559| 5.7327|0.008| 0
8806.19992| 5.7170|0.008| 16
8950.69100| 5.6957|0.013| 2
8950.76559| 5.7059|0.007| 2
8950.77989| 5.8816|0.024| 34
8974.75554| 5.6967|0.005| 0
8974.76985| 5.7342|0.009| 65
9019.73030| 5.6917|0.006| 2
9047.31327| 5.7211|0.006| 0
9047.32758| 5.7043|0.006| 0
9047.40220| 5.7077|0.005| 0
9047.41647| 5.7083|0.006| 0
-------------------------------
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