Solar Maximum Mission (SMM) Coronagraph/Polarimeter (C/P) Data Avail
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P/1999 R1 in 1987
Hi Rainer,
> I have seen most of the gif images and have found three of Jupiters
> moons and stars to mag 6. There should be enough sensitivity.
Well, that's promising -- and indeed I've now managed to find a
5th magnitude star.
> I think that P/1999 R1 was outside the small field of view in
> August 1987. The SMM FOV is smaller than the C2 FOV. The path of
> the comet is outside of the C2 FOV in Mid-August.
I show it a little more than 3-1/2 solar diameters away at perihelion
on 8/26/1987, which as you point out is definitely outside the FOV
of SMM. I'm not sure how quickly this comet fades after perihelion,
but if it could hold on for 5 more hours, it pulls to within two solar
diameters. --Rob
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Re: [sohohunter] P/1999 R1 in 1987
On 25 Sep 2007, at 14:39, Matson, Robert D. wrote:
> Hi Rainer,
>
> > I have seen most of the gif images and have found three of Jupiters
> > moons and stars to mag 6. There should be enough sensitivity.
>
> Well, that's promising -- and indeed I've now managed to find a
> 5th magnitude star.
>
> > I think that P/1999 R1 was outside the small field of view in
> > August 1987. The SMM FOV is smaller than the C2 FOV. The path of
> > the comet is outside of the C2 FOV in Mid-August.
>
> I show it a little more than 3-1/2 solar diameters away at perihelion
> on 8/26/1987, which as you point out is definitely outside the FOV
> of SMM. I'm not sure how quickly this comet fades after perihelion,
> but if it could hold on for 5 more hours, it pulls to within two solar
> diameters. --Rob
>
>
Actually, the perihelion time of P/1999 R1 in 1987 was even more
unfavourable: integrating the orbit from MPEC 2007-S16 to 1987
with SOLEX, I find T = 1987 August 17 (not late August).
I have made a page with my early SMM experiences;
http://www.rkracht.de/smm/smmcp.htm
Rainer
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Re: [sohohunter] P/1999 R1 in 1987
Hi Rob,
> of SMM. I'm not sure how quickly this comet fades after perihelion,
> but if it could hold on for 5 more hours, it pulls to within two solar
> diameters. --Rob
The peak brightness is approximately 4 hours after perihelion (note: perihelion
is not equal to the max. elongation!). Then, it fades rather quickly,
approximately 0.5-1mag per hour.
Cheers,
Sebastian
**********
[Fwd: Re: [sohohunter] P/1999 R1 in 1987]
> Then, it fades rather
> quickly, approximately 0.5-1mag per hour.
Well, this was too pessimistic (didn't remember correctly). From a quick check
with the light curve, I find that 1 mag decreas in brightness corresponds to
~0.35 days (= 8 hours).
Hope this helps,
Sebastian
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RE: [sohohunter] P/1999 R1 in 1987
Hi Rainer,
> Actually, the perihelion time of P/1999 R1 in 1987 was even more
> unfavourable: integrating the orbit from MPEC 2007-S16 to 1987 with
> SOLEX, I find T = 1987 August 17 (not late August).
Even so, the portion after perihelion does intersect the field of view.
However, I did not find it -- at least in my scanning of the jpegs from
8/12 to the end of the month. (I was able to easily see stars of +5.3
and +5.4, so I would think I could have pulled out +6 if it was in the
FOV.) If I had a fairly confident perihelion date with some error bars,
I'd be willing to dig into the fits files to see if I could go a bit
deeper with additional processing.
> I have made a page with my early SMM experiences;
> http://www.rkracht.de/smm/smmcp.htm
Very nice! A little web-searching reveals that SMM has been credited
with 10 sungrazing comet discoveries. The first, SMM-1, is quite bright
and clearly visible in the last two ss images of 10/5/1997. Even
brighter is SMM-2, visible in the last three ss images of 10/17/1997.
Both of these were Kreutz comets.
--Rob
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RE: [sohohunter] P/1999 R1 in 1987
On 25 Sep 2007, at 15:38, Matson, Robert D. wrote:
> Hi Rainer,
>
> > Actually, the perihelion time of P/1999 R1 in 1987 was even more
> > unfavourable: integrating the orbit from MPEC 2007-S16 to 1987 with
> > SOLEX, I find T = 1987 August 17 (not late August).
>
> Even so, the portion after perihelion does intersect the field of view.
> However, I did not find it -- at least in my scanning of the jpegs from
> 8/12 to the end of the month. (I was able to easily see stars of +5.3
> and +5.4, so I would think I could have pulled out +6 if it was in the
> FOV.) If I had a fairly confident perihelion date with some error bars,
> I'd be willing to dig into the fits files to see if I could go a bit
> deeper with additional processing.
>
> > I have made a page with my early SMM experiences;
> > http://www.rkracht.de/smm/smmcp.htm
>
> Very nice! A little web-searching reveals that SMM has been credited
> with 10 sungrazing comet discoveries. The first, SMM-1, is quite bright
> and clearly visible in the last two ss images of 10/5/1997. Even
> brighter is SMM-2, visible in the last three ss images of 10/17/1997.
> Both of these were Kreutz comets.
>
> --Rob
>
I have added the first four SMM (Kreutz) comets to the page.
Rainer
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Re: [sohohunter] P/1999 R1 in 1987
Rob,
> Even so, the portion after perihelion does intersect the field of view.
> However, I did not find it -- at least in my scanning of the jpegs from
> 8/12 to the end of the month. (I was able to easily see stars of +5.3
> and +5.4, so I would think I could have pulled out +6 if it was in the
> FOV.) If I had a fairly confident perihelion date with some error bars,
> I'd be willing to dig into the fits files to see if I could go a bit
> deeper with additional processing.
You might try the following:
TP = 1987 Aug. 22.61
q = 0.0596
e = 0.97642
i = 13.47
Peri = 40.14
Node = 8.60
a = 2.52927
P = 4.02
Sebastian
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Re: [sohohunter] P/1999 R1 in 1987
Ah, it's too late. I should go to bed...
> TP = 1987 Aug. 22.61
Should read: TP = 1987 Aug. 21.75
Sebastian |
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