[vsnet-chat 4242] DE Dra confusion ?

[Kari Tikkanen <ktikkane@mail.student.oulu.fi>]

>From: Thom Gandet <tgandet@mindspring.com>
>Subject: DE Dra: Predicted Minima


Hi!

Thom said:
>quoted, eclipses would have occurred on the following HJD dates:
>
>            Predicted Minima        Hipparcos Minimum    Probable     
>          Min I:        Min II:                          Minimum   
>      2448072.771   2448075.742        2448074.50          II         
>         8157.540      8160.510           8160.03          II
>         8316.582      8319.453           8317.112          I
>         8348.371      8351.242           8349.114          I
>         8438.439      8441.310           8438.858          I
>         8660.853      8663.831           8660.99           I
 ...

>   Kari Tikkanen reported observing minima, of unspecified magnitude,
>at JD 2451996.43 and JD 2452013.5.  The spectrographic orbit predicts
>eclipses at JD 2451996.189 (Min. II), and at JD 2452014.510 (Min. I).

You mixed stars.
Those 2451996.43, 2452013.5 were my  DK Cam minima 
not DE Dra minima.
 
Also Your Hipparcos Minimum list mixes two star minima together.

I found only these HIP mags for DE Dra around those on list: 
............................
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

8438.84349| 5.6872|0.008|  0
8438.85783| 5.7120|0.006|  0 
............................
So 1st,2nd and 6th minima on your list are from DK CAM 
and 3rd,4th,5th from DE Dra obs of Hipparcos.

Generally HIP mag range for DE Dra is around 5.70..5.72 (quite
constant). 

(Sorry, I should really have splitted my email to two different 
 emails..)
 

With Best Regards,
 Kari Tikkanen.

VSNET Home Page

Return to Daisaku Nogami

---

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