| Richard Harshaw | ||||
| Star:
South 617 [ADS 7967]
Location of site: Northern Kansas City, Missouri (USA) 94d 30m west longitude, 39d 15m north latitude 980 ft above Mean Sea Level Date of observations (UT): 0300, 02-28-00 LT: 2100, 02-27-00 Site classification: suburban Sky conditions: seeing-- 6 out of 10 up to 8 (varied quickly and often) transparency-- 5 out of 10 up to 8 (high, thin clouds were in the area) limiting visual magnitude: 4.5 Temperature: 40F Telescope: Celestron C-8 Eyepiece: Micro-Guide (160x) |
Primary, 6.2 mag, K0
Companion, 10.2 mag; 35" sep at PA 178 I made five pairs of separation and PA measures using the Micro-Guide and got an average of 36" in PA 177. I noted colors of orange and bluish-white.
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| Dave Mitsky | ||||
| Star:
South 617
Date & Time: 2000/2/23, 01:27 UT Seeing: 5 <1-10 Seeing Scale (10 best)>. Transparency: ~ 5 Location of site: ASH Naylor Observatory (http://www.msd.org/obs.htm) near Lewisberry, PA Site classification: Rural Sky darkness: ~ 5.0 <Limiting magnitude> Telescope: 17" f/15 classical Cassegrain Dome Temperature: 6° C Magnification: 118x, 144x Oculars (17"): 55mm University Optics Ploessl (118x), 45mm U.O. Ploessl (144x)
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S617 is a wide pair (35.2") that was nicely split at 118x. The pale
blue comes is almost due north (178°) of the off-white primary.
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| Francisco Manuel Rica | ||||
| Star:
South 617
Date & Time: Several dates Seeing: --- <1-10 Seeing Scale (10 best)> Location of site: Extremadura, Spain Site classification: Suburban Sky darkness: --- <Limiting magnitude> Telescope: In some measurements, S/C 13" with CCD ST 7 Magnification: --- |
1. LOCATION
About 2 degree W. from 61 Leonis. 2. "A" COMPONENT Name
: SAO137863
It is a spectroscopy binary with a period of 1166 days and a major semiaxes
of 0.009 arcsec.
Name
: SAO137864
I’m not able to measure S617 by problems in my telescope. S617 was discovered in 1824 by Jhon South. At this epoch, PA = 178 and D = 35.2. Since then, 7 measurements have been made between 1824 and 1925. The straight-line fit of this measurements indicate AP = 178 and D = 35.2 at XIX and XX century. HIPPARCOS/Tycho measured the S617 stars position in 1991. The results: PA= 178.1 and D=35.2. I calculated ephemerids for 2000.0 epoch: Ephemerids for 2000.0 epoch
5. TYPE OF DOUBLE The A and B component proper motion are very high. This is an unusual
proper motion. Only 30 star from 2.5 million stars from Tycho-2 catalog
has similar proper motion. Both proper motion are VERY similar and therefore
surely S617 is a phisycal double star. If this were thus, it would be located
at 260 light-years. The proyected separation line is 2800 U.A.
We can convert the angular separation (D) in an expected major semiaxes by followed formulae: E(a) = 10 power at (0.146 + log D) Where E(a) is the expected major semiaxes and D is the angular separation The above formulae was obtained by me for the calculing of E(a) using the original formulae: E(log a) – E(log D) = 0.146 This formulae was derived by Couteau in 1.960 on theoretical grounds, assuming a random dostribution of the geometrical elements of the orbit between others. Although it was derived therically, Couteau also checked its obsevational validity using a group of 410 orbits, for which the constant turned out to be 0.150. I tested it calculing the expected major semiaxes on an orbital double. The difference between a and E(a) was 0.1 arcsec. Thus the expected major semiexes for S617 could be 49.8 arcsec ( = 3974 U.A.) A component could be a 2.3 solar mass star; B a 1.2 solar mass star. Using Kepler's third law the period could be 135000 years. By mean, each 370 years the double star move 1 degree. The relative movement of B (who have not changed the position angle
in 175 years) is in concordance with the above data.
(H) = HIPPARCOS data
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| Philippe de Jocas | ||||
| Star:
South 617
Date & Time: March, 24-25 Seeing: fair to good, 4 to 6 <1-10 Seeing Scale (10 best)>. Location of site: Ottawa/Hull, Canada Site classification: Suburban Sky darkness: 4.4-4.5 <Limiting magnitude> Temperature: 6-7C, , light Westerly winds and slighltly hazy skies Telescope: 6" f5 newtonian Magnification: 110x |
S617 was best seen at 110x showing a golden primary and a dusky blue companion. As well, and though it was probably a field star, I could see a faint third member, about 11 mag., some 150" in the NE/NEN by the way, I remember a discussion on estimating PA. For my part I have a plastic disk with N, NNE, NEN,...etc. written on it. By moving the scope in dec. and checking the line going from the primary to the companion unto the disk I find that I can estimate the PA fairly accuratly, leading me to write like I did for S617, NE (the main direction)/NEN (leaning toward). | |||
| Ilario Melandri | ||||
| Star:
South 617
Date & Time: 30 Mar 2000 – 21.50 UTC Seeing: 6 <1-10 Seeing Scale (10 best)> Location of site: Italy, Ravenna, San Romualdo, Lat 44 32’N Lon 12 08’E Elevation: 0 m Site classification: Rural Sky darkness: 6 <Limiting magnitude> Temperature: +7C Telescope: 150 mm f/15 achromatic refractor (lens by Romano Zen, Venice) Magnification: 140 x (eyepiece Plossl Clavé 16 mm) |
Note: the companion seems to be brighter than m 10.
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