Cosmos 2360 r acceleration, call for observations !!

Kurt Jonckheere (
Mon, 3 Aug 1998 22:13:11 +0100 (WET DST)

Cosmos 1360 r (Zenit-2) = 25407 = 98-45 B is accelerating !, 
this means the rotation period of the rocket is going down, 
thus the rocket is rotating faster and faster around its body axis(ses).
Zenit rockets are very bright (around mag +2.5 at maximum) and thus easy
to observe naked eye.  As noted before on SeeSat-L Zenits often do flash 
during some part of the transit and are steady otherwise.  So don't give up
watching too early !!

According to the data below it looks like that the minimum of the rotation
period has probably almost been reached, so all accurate timings are
appreciated very much !!

Rainer Kracht wrote :
>According to Pierre Neirinck 98-45B is accelerating.
>98-45B  Almost regular variations +2 +5 in E and W
>Sharp tumbling acceleration. So far, photometric periods measured
>from Malo les Bains (2563) are:
> July 29.96  4.543 +-0.04 sec (3,4,5 and 20 periods)
  July 30.16  3.78  +-0.1  sec (Walter Nissen, see below)
  July 30.17  3.5              (Eric Vondra, see below)
> July 31.87  2.791 +-0.01     (4,6,10,44)
> July 31.94  2.771 +-0.01     (4,6,8,10,56)
  Aug   1.8   2.75             (Bjorn Gimle, see below)
>                              Pierre Neirinck
Data from SeeSat-L :
98- 45 B 98-07-30  4: 9:50.6 WN   22.7  .8   6    3.78 __', C* 2360 r, 
Bjorn Gimle :
I agree, but at 20:33 UT Aug.1 in the SW (from home) the variation was too
small to state positively. I timed 12 intervals in 33.0 seconds i.e.  2.75 seconds.
Eric Vondra:
>I observed Cosmos 2360 (98 045A) and the SL-16 rocket (98
>045B) tonight (~0410 UT July 30). The rocket was flashing
>with an approximately 3.5 second period from 4.0 to 7.0 mag.
>The satellite was steady at 5.0 mag. (My mag estimates were
>difficult due to some murky clouds).

SL-16 R/B (elements coming from OIG)
1 25407U 98045B   98212.13714424 -.00000048 +00000-0 +00000-0 0 00233
2 25407 071.0125 125.1866 0009743 270.7594 089.2412 14.14846334000398

>It would be helpful to collect world data to monitor the changes
>(July 28,30,Aug 01)
In fact we ARE collecting all observations of flashing satellites.
It is very much appreciated when you enter your observations in our 
PPAS-format (like Walter is doing) and also send them to    But also when lack the time to enter
them in the correct format, please do send them to the address 
In this way they are surely included in our database which already 
contains more than 40 000 observations.  Take a look at it starting 
from the VSOHP : and select
"Photometric Periods of Artificial Satellites", the name of our database.

Every two months or so, an update to this database is made available 
via e-mail from our archive.  A new update will be issued around 15
August.   If you want to make your observations of flashing satellites 
(e.g. of this very interesting Zenith rocket) available for analysis
please send them...


Kurt Jonckheere

    Kurt Jonckheere (  51.2 N  2.9 E  4m ASL 
      Accelerations :
    Observations collector for the Belgian Working Group Satellites: 
Send your observations of flashing satellites, preferrably in the correct
             PPAS format to
 "Join as at Eurosom 3 in Edinburgh, Scotland on October 24/25, 1998"