[vsnet-chat 1060] (fwd) IP Peg minimum (Masi)

[Taichi Kato <tkato>]

From gianmasi@fr.flashnet.it Fri Jul 17 22:15 JST 1998
Date: Fri, 17 Jul 1998 14:10:18 +0200
From: Gianluca Masi <gianmasi@fr.flashnet.it>
MIME-Version: 1.0
To: Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>
Subject: Re: IP Peg Eclipse
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Dear Taichi Kato,
many thanks for your kind message.

As regards the ephemeris, I used the following data for IP Peg:
Min.HJD = 2449591.29361 + 0.15820616E

My own software indicates that a minimum is expected at

980717 00:14:51 (UT, Heliocentric)

Introducing the heliocentric correction, I obtain the following time:

980717 00:10:27 (UT, Geocentric)

This second time agrees very well with the minimum on my light curve
(http://vsnet.eurolink.it/comets/ippeg.gif), which uses geocentric time.

I give you some details about my calculus, to permit your evaluation:

at 1998 07 17.0 UT (JD=2451011.5), the variable did 

(2451011.5-2449591.29361)/0.15820616=8976.9348 cycles

The cycle 8977 (minimum) is expected at 

8977*0.15820616+2449591.29361=2451011.510308 (JD, Heliocentric), 

that is 980717 00:14:51 (UT, heliocentric). 

Introducing the heliocentric correction, I get  

980717 00:10:27 (UT, geocentric).

What do you think?

Best regards and thank you for your attention.

Gianluca





Taichi Kato wrote:
> 
> Dear Gianluca Masi,
> 
>    Congratulations on your success in observing!  Please keep an excellent
> work!
> 
>    I have recalculated the ephemeris.  The times are geocentric (helio-
> centric collection applied).  The same element is used.  What has caused
> inconsitencies?
> 
>   YYMMDD hh:mm:ss (UT)
>   980717 00:11:24 (*)  this one
>   980717 03:59:12
>   980717 07:47:00
>   980717 11:34:47
>   980717 15:22:35
>   980717 19:10:23
>   980717 22:58:11
> 
>   980718 02:45:59
>   980718 06:33:47
>   980718 10:21:35
>   980718 14:09:23
>   980718 17:57:11
>   980718 21:44:59
> 
> Regards,
> Taichi Kato

-- 
***********************************************************************
* Gianluca Masi                           "Two things fill the soul   *
* Via Madonna de Loco, 47               with awe and reverence [...]: *
* 03023 Ceccano (FR)                     the starry sky above me and  *
* ITALY                                    the moral law within me"   * 
* email: gianmasi@fr.flashnet.it                                      *
* http://vsnet.eurolink.it/comets/                        I. Kant       *
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