Re: annular eclipse october 3rd madrid/ attention: javi el zaragozano

From: Rodney Austin (rodcomet@gmail.com)
Date: Sun Sep 25 2005 - 06:22:26 EDT

  • Next message: Stephen E Bolton: "RE: annular eclipse october 3rd madrid/ attention: javi el zaragozano"

    Hi All,
                During a total only the brightest satellites would be
    visible; but during an annular, perhaps the brightest of Iridium
    flares would be detectable. Venus certainly and 'maybe' Jupiter at
    best. Anything fainter than about 0 magnitude would be extemely
    difficult, and that is during the annular phase itself. Outside
    central phase I would say you would have very little hope of seeing
    any satellites. Of course if you have a decent sized telescope aimed
    precisely, then who knows?
    Sorry to sound so negative, but having been to several total and
    annular eclipses over the years, I really would not hold out too much
    hope for the sky to get dark enough to do anything really useful.
    However, I wish you all every success.
    Rod Austin
    
    On 9/25/05, b_gimle@algonet.se <b_gimle@algonet.se> wrote:
    > I wrote the attached message to Dan, Russell, Gerhard (and Rob)
    > Using Rob's SkyMap you can get predictions for daytime (but you
    > might want to AVOID those where SP5;PA occur)
    >
    > Anyway, Sun and Moon are only at 28 deg elevation, so a satellite
    > at 800 km crosses the shadow some 1500 km SE of Madrid,
    > and in other directions it is more or less free from the dense part.
    > Some satellites passing 8:58?- 1 min.:
    >  24966 IRIDIUM 35
    >  15032 SL-8 R/B
    >  25261 ARIANE 40 R/B
    >  23323 IRS P2
    >  11416 NOAA 6
    >  28680 SL-12 DEB
    >  13923 NOAA 8
    >  11672 SL-14 R/B
    >  13128 SL-8 R/B
    >  13552 COSMOS 1408
    >  14680 SL-8 R/B
    >  25695 SS-18 R/B
    >  26083 GLOBALSTAR M060
    >  10544 NOSS 2 (E)
    >  26222 CZ-4 DEB
    >
    > But I find Iridium 7 passing 09:36 (and no flare at all during eclipse)!
    >
    > /Björn
    >
    > ----- Original Message -----
    > ...
    > > how can I get predictions for if and when such objects might be visible?
    > > using starry night pro (which doesn't list too many LEO objects) for
    > > example, I notice iridium 7 is in the area at the time of the peak.
    > will
    > > it be obscured by the umbra for the entire time it's in line-of-sight
    > with
    > > madrid?
    >
    > ------------------------------------------------------
    >
    > Since SkyMap 6.1:
    >
    >      When F8 (Check for satellites in lunar umbra) is "On", program
    >      determines if moon occults any portion of the sun as seen from
    >      the satellite.  If so, the satellite visual magnitude is adjusted
    >      to account for the fraction of the sun occulted.
    >
    >      If the sun is more than 50% occulted, the satellite track color
    >      is set to dark blue.  (This is a slightly darker blue than the
    >      blue used for tracks when the earth limb is blocking part of the
    >      sun.)  If the sun is more than 90% occulted, the satellite track
    >      color is set to dark purple (a darker purple than that used for
    >      tracks dimmer than the satellite magnitude limit).
    >
    > Apart from the fact that my ability to associate the colour of a line
    > with the proper description, plotting "all" satellites makes the
    > graph unreadable. See Eclipse2.gif!
    >
    > NB - I omitted this because it is 635 kB (~800 in transmission)
    > Let me know if you still want to see it!
    >
    > But turning on option F6 (HPGL output) creates a text file where the
    > colour codes can be easily located with a good text editor (I use
    > UltraEdit, which also can record macros to process the complete file)
    >
    > With this method I located "all" objects that showed a 'SP5;PA' from
    > 06:00 to 10:19 UTC above horizon from Dan Deak's location.
    > I used a mag limit of 13, and range 55555 km (!) to get the list,
    > but of course you can set lower limits though using the same set.
    > I also set 'Horizon' mode (F7/F7) to get alt/az correct (not the star
    > track) regardless of time.
    >
    > You can use the attached file eclipsed.sel to extract elsets for
    > relevant objects from a large tle file.
    > Use my program   'applysel.exe  large.tle eclipsed.sel   eclipsed.tle'
    > or Mike's        'xf6.exe       eclipsed.sel   large.tle eclipsed.tle'
    > but in the latter case my comments (HP plot coordinates for start
    > of SP5 color code) will appear as TLE lines 0.
    >
    > Of Russell's suggestions, my list contains only 23561, 22566, 22220, 15944,
    > 13367, but #15644 is a beauty!
    >
    > Cosm1674c.gif shows that #15644 is predicted to dip to mag +13.5
    > right after culmination, despite a favourable phase angle.
    >
    > Cosm1674c.bmp is an enlargement (before conversion to .gif) where the
    > colour
    > changes from SP6 to SP5, 1 second before 8:37 UTC.
    >
    > DanmDea6_E is a prediction for objects that could reach mag +6, but I used
    > PaintShopPro to change yellow, blue, red to black in the Edit Color Palette
    > menu, enhancing the SP5 sections.
    >
    > /Björn
    >
    >
    >
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