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Re: [tec-scopes] Re: Doubles tonight

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  • Chris Lord
    ·202 is a fairly easy pair for a 6-inch. You just need good seeing. Given the 0.9magdiff, and Jim s 160 Fluorite OG, in Seeing Antoniadi I, S/rho = 1.242 =
    Message 1 of 6 , Dec 1, 2009
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      ∑202 is a fairly easy pair for a 6-inch. You just need good seeing.
      Given the 0.9magdiff, and Jim's 160 Fluorite OG, in Seeing Antoniadi I,
      S/rho = 1.242 = 144/D(mm) arcsecs. Current sep is ~1."8 (its a fairly
      slow orbit approaching periastron in a ~100 years). I've seen it in a
      6-inch f/8 Newtonian, and its not too difficult in my TEC140.

      I see Jim has tried Lambda Cyg with bigger 'scopes, and found it very
      difficult. It is, but I managed to split it in the 1970's when the sep
      was 0".9 using Rossall's 6.3-inch Cooke. It is steadily closing, but is
      still ~0".8. For a 1.6magdiff S/rho = 164/D(mm), so you won't clearly
      split it, but in excellent seeing you ought to see it elongated.

      One you might like to have a go at is in Draco, ∑2438 which is at
      apastron, ~0".9arc and an equal mag 7 pair. Its a fair test for a
      6-inch. I've elongated it in my TEC140, and split it in the 6.3-inch
      Cooke. <http://www.dibonsmith.com/dras2438.gif>

      Chris Lord
      On Dec 01, 2009, at 00:54, tucstargzr wrote:

      > Hi Jim,
      >
      > With that scope, and pondering Chris Lord's messages, why not give
      > Alpha Psc a whirl (it's the bottom of the "V"). And then about 1.5
      > degrees up and to the right is a more challenging double STF 186.
      >
      > Tom
    • jimhp29401us
      Yes, you are correct. I did split 36 Andronmedae which is listed as mags 6.1 and 6.5 with a separation of 1 Nov 19, 2009 using the TEC 160 plus 6mm TMB
      Message 2 of 6 , Dec 1, 2009
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        Yes, you are correct. I did split 36 Andronmedae which is listed as mags 6.1 and 6.5 with a separation of 1" Nov 19, 2009 using the TEC 160 plus 6mm TMB monocentric plus Zeiss 2X Barlow.

        Jim

        --- In tec-scopes@yahoogroups.com, Chris Lord <chrislord@...> wrote:
        >
        > ·202 is a fairly easy pair for a 6-inch. You just need good seeing.
        > Given the 0.9magdiff, and Jim's 160 Fluorite OG, in Seeing Antoniadi I,
        > S/rho = 1.242 = 144/D(mm) arcsecs. Current sep is ~1."8 (its a fairly
        > slow orbit approaching periastron in a ~100 years). I've seen it in a
        > 6-inch f/8 Newtonian, and its not too difficult in my TEC140.
        >
        > I see Jim has tried Lambda Cyg with bigger 'scopes, and found it very
        > difficult. It is, but I managed to split it in the 1970's when the sep
        > was 0".9 using Rossall's 6.3-inch Cooke. It is steadily closing, but is
        > still ~0".8. For a 1.6magdiff S/rho = 164/D(mm), so you won't clearly
        > split it, but in excellent seeing you ought to see it elongated.
        >
        > One you might like to have a go at is in Draco, ·2438 which is at
        > apastron, ~0".9arc and an equal mag 7 pair. Its a fair test for a
        > 6-inch. I've elongated it in my TEC140, and split it in the 6.3-inch
        > Cooke. <http://www.dibonsmith.com/dras2438.gif>
        >
        > Chris Lord
        > On Dec 01, 2009, at 00:54, tucstargzr wrote:
        >
        > > Hi Jim,
        > >
        > > With that scope, and pondering Chris Lord's messages, why not give
        > > Alpha Psc a whirl (it's the bottom of the "V"). And then about 1.5
        > > degrees up and to the right is a more challenging double STF 186.
        > >
        > > Tom
        >
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