| William L. Schart | ||||
| Star:
Tau Orionis
Date & Time: November, 23th, 1998 - 10:00 pm CST Seeing: 8 <1-10 Seeing Scale (10 best)> Location of site: Killeen, TX (Lat 31 N, Elev 600 ft) Site classification: Suburban Sky darkness: 4 <Limiting magnitude> Telescope: Orion 6" Dob. Magnification: 48x, 120x Star: Tau Orionis Date & Time: 12/26/99 10:50 pm CST Seeing: 7 <1-10 Seeing Scale (10 best)> Location of site: Killeen, TX (Lat 31 N, Elev 600 ft) Site classification: Suburban Sky darkness: 4.5 <Limiting magnitude> Telescope: Orion 6" Dob. Magnification: 32x, 48x, 72x, 98x, 144x |
Too faint to
see naked-eye in my skies, it was easily located in the same finder field
as beta Ori. The primary was white and the secondary was very, very
faint. I was able to split this
at 48x, but the secondary was extremely faint and I had to use averted
vision, so again I did not attempt any measurements.
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| Craig M. Carver | ||||
| Star:
Tau Ori
Date & Time: 11/26/98 2245 LT Seeing: 5 <1-10 Seeing Scale (10 best)> Location of site: Randalman, NC (Lat 36.07, Long 79.79, Elev. 500 ft) Site classification: Rural Sky darkness: 4.8-5.0 <Limiting magnitude> Telescope: 6" Maksutov Magnification: 95x |
This is a wide double, with
a white primary and a faint (mag 11) companion, whose color I can't make
out. The sky is dark but has patchy clouds and
occasional haze. The quarter moon is still up 25 degrees from the horizon. |
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| Chuck Layton | ||||
| Star:
Tau Ori
Date & Time: Dec.20, 1998, 06:40 UT Seeing: 4 <1-10 Seeing Scale (10 best)> Location of site: Tacoma (WA) Site classification: --- Sky darkness: 4.4 <Limiting magnitude> Telescope: 20cm f/6 Eq. Newtonian Magnification: : 76x |
Observed Colorations
of Components: Primary - yellowish white, comes - white?
Other comments: Finding the 11th mag. D component in my light-polluted neighborhood was quite challenging. With averted vision it was only just visible. Not sure about its color. |
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| Paolo Morini | ||||
| Star:
Tau Orionis
Date & Time: 15 Jan 1999, approx 21:20 UTC Seeing: 6 <1-10 Seeing Scale (10 best)> Location of site: San Romualdo, a little village in the country near Ravenna – Italy. Site classification: Suburban Sky darkness: 5 <Limiting magnitude> Telescope: Takahashi FS102 Magnification: 164x (LE5 Tak eyepiece) |
The fourth observing session
about this program took place at San Romualdo, a little village in the
country near Ravenna – Italy.
I have made the final test of my new wood tripod – it works fine. This is my report about the project – I hope to complete the list for the end of the program. The weather was foggy and the transparency was not very good, but the air was very steady. Around midnight there was ice on the scope! No coloration observed. The 2nd component was visible only using adverted vision |
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| Dave Mitsky | ||||
| Star:
Tau Orionis
Date & Time: 1/19/99 02:28 UT Seeing: 6 <1-10 Seeing Scale (10 best)> Transparency: ~ 4 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 Magnification: 118x, 202x |
A wide pair (36.2"), also
designated as h2259, with a large magnitude difference (4.0 and 11.0) and
no obvious coloration.
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| Orlon Peterson, Marilyn Head, Giles Reid and David Downing | ||||
| Star:
Tau Orionis
Date & Time: 13/02/99, 10:00UT to 14:00 UT Seeing: 7-8 got better as night progressed Location: Staveley, ~80km SW of Christchurch, New Zealand. Instrument: 102mm f/9.8 refractor Sky darkness: 6 - 6.5 <Limiting magnitude> Again didn't actually make a definitive measure but the sky was dark and the transparency really good. Magnification: 50x |
This appeared at 50x to be a widely separated double. This makes me suspicious that I may have seen a field star. | |||
| Ilario Melandri | ||||
| Star:
Tau
Orionis
Date & Time: 6/Dec/1999 – 21.26 UTC Seeing: 4 <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: 5.5 <Limiting magnitude> Temperature: 0C Telescope: 150 mm f/15 achromatic refractor Magnification: 140 x (eyepiece Plossl Clavé 16 mm) |
 |
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| Tomás Vazquez | ||||
| Star:
Tau Orionis
Date & Time: December, 16, 1999 21:29:33 UT Seeing: 4 <1-10 Seeing Scale (10 best)> Location of site: 37 24 N. 5 58 W. Sevilla, Spain Site classification: Urban Sky darkness: 3 <Limiting magnitude> Telescope: Celestron C8” D:203mm. f/6,3 Magnification: CCD Camera
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Observing Method: CCD ST-4
Camera
Integration time: 20 seconds Software used (reading/treatment): Lucas 1.1 / Laia 3.1g Image Position: North up, East left Is an easy to split double star. The main component has a magnitude of 4, being a spectroscopic binary. The secondary has magnitude 11 and is located at 36.2” with an apparent angle of 60 degrees. In this image, we can observe a third star located about the same distance as the secondary in position AP 240º. Having a fainter magnitude I don’t find any reference in standard catalogues for it.
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| Richard Harshaw | ||||
| Star:
Tau Orionis [20 Ori; H V 25; AB = Bur 188; AC = h2259; ADS 3877; SAO 131952]
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): Dec 29, 1999 (0200 to 0400 UT) Site classification: suburban Sky conditions: seeing-- began at 8 out of 10, degraded to 6 by 0400 UT transparency-- 8 out of 10 limiting visual magnitude—4.5 Temperature: began at 40F, dropped to 26F by 0400; no wind at first, but a breeze picked up slightly as a front passed by about 0330 UT Telescope: Celestron C-8 Eyepiece: 7.4 mm Plossl (270x) |
Colors of white
(B5III), ???, and Yellow.
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| David Bushard | ||||
| Star:
Tau Orionis
Location of site: River Falls, WI (USA) longitude 92, latitude 45N elevation approx 800 ft (246 m) Date of observations: 29 Dec 1999, 8:00 to 11:00 pm local time (CST) Site classification: rural Sky conditions: Seeing: 6 of 10, improving later transparency: 6 of 10 limiting visual magnitude: 5.2 Temperature: 25 F (-3 C), winds light and variable Telescope: Meade 12" LX-200 EC Eyepiece: Televue 9mm Nagler (338x) |
AxBC is not
difficult, but BC is difficult even at 435x, which showed an
elongation but not a clear split. D was clearly seen. A appears yellowish or yellow white, the other components are too dim to show color (to me, anyway).
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| Allen Ginzburg | ||||
| Star:
Tau Orionis
Date & Time: 01/03/2000, 05:51 UTC Seeing: 8 <1-10 Seeing Scale (10 best)> Location of Site: Aptos, CA (USA) Site Classification: Suburban Sky darkness: 4 <Limiting magnitude> Telescope: Meade LX-200 /f10 Magnification: 208x
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I am not sure
of this one. The primary was visible with two companions, one on
either side, each about 30" from the primary. I don't know if these
are actually part of the double star system, or if they are just some unrelated
stars and the actual secondary was not visible.
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| Giuseppe Bandini | ||||
| Star:
Tau
Orionis
Date & Time: 5/Jan/2000 - 20.50 UTC Seeing: 4 <1-10 Seeing Scale (10 best)> Location of site: Italy, Ravenna, Elevation: 0 m Site classification: urban Sky darkness: --- <Limiting magnitude> Temperature: +1C Telescope: Celestron 8” Magnification: 80 x (eyepiece 25 mm Plossl) |
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| Randall Heckman | ||||
| Star:
Tau Orionis
Date & Time: 01/08/00 AT 2:15 UT Seeing: 5-6 Location of Site: Heckman Observatory 40 37' 10" N and 99 03' 50" W Site Classification: Rural Sky Darkness (Limiting Magnitude): 5+ Telescope: 8" Orion Dob Magnification: 120x |
Separation (Clear or Toughing):
Clear
Magnitude Comment: Secondary extremely dim Color Comment: White General Comment: The secondary was at the extreme limit of my averted vision. The position angle was very important to certain identification.
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| Orlon Petterson | ||||
| Star:
Tau
Orionis
Date & Time: 10:00 - 12:00 UT 20/01/2000 Seeing: 3 <1-10 Seeing Scale (10 best)> Location of site: Christchurch, New Zealand Site classification: Suburban Sky darkness: 5 <Limiting magnitude> Telescope: C102HD f/10 refractor Magnification: 50x, 83x |
Clear night
with a warm light NW breeze, near Full Moon, but with seeing like looking
up from the bottom of a swimming pool. Companion only just seen in
moments of steady seeing, incredibly faint and nearly missed. Seconday
seen to SSW of primary.
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| Jim Brownfield | ||||
| Star:
Tau
Orionis
Date & Time: 26/01/2000, 6:30 p.m.- 11:30 p.m. EST Seeing: 3 – 5 (improving) <1-10 Seeing Scale (10 best)>. Location of site: Huntsburg, Ohio, USA Site classification: Suburban Sky darkness: 6 mag., could see ST 855, going to 5th mag. star Rho <Limiting magnitude> Other observing conditions: 83% humidity, 16 degrees F. with 12" snow on ground going to 84% humidity, 4 degrees F. Telescope: 13.1"/F4.5 Dobsonian, with 5" aperture mask for the brighter pairs Magnification: 47x, 140x |
split at 47x using averted vision, 140x best for bringing out 13.6 mag star | |||
| Bill Becker | ||||
| Star:
Tau Orionis
Location of site: Casper, Wyoming Elev. 5200' Date of observations: Feb 16 2000, 3:38 UT Site classification: Suburban Sky conditions: Seeing: 7 Magnitude limit (naked eye): 4.0, Moonlight Telescope: Quantum 4 Maksutov Magnification: 85x to 191x |
I revisited
Tau Ori and found at 191x using a Brandon 8mm, a faint star of about 35"
seperation from the primary. It looked to be about 11th magnitude, however
the PA appeared to be more like 50* rather than the 250* listed in the
Feb issue of S&T. Primary seen as white with no colour noted in the
faint companion.
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| Jay Zimmerman | ||||
| Star:
Tau Orionis
Date & Time: 03/06/00, 0330 UT Seeing: 6 <1-10 Seeing Scale (10 best)> Location of Site: Carbondale, IL, USA Site classification: Suburban/ near rural Temperature: 37°F (2.8°C) Sky darkness: 5.9 <Limiting magnitude>t Telescope: 94mm, f7 apo Magnification: 128x |
Relatively
high power and a. v. were needed to see the secondary clearly, not to separate
the stars. Colors: A = white; B = ? This was a night of exceptional transparency
for my location so I attempted to find some dim secondaries that had proved
too elusive in the past. This was one of them.
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| G.E.O.D.A Group | ||||
| Star:
Tau Orionis
Date & Time: 5-III-2000, 19:00-22:00 UT Seeing: 8 <1-10 Seeing Scale (10 best)> Location of Site: Manises, Valencia, Spain. GPS coordinates: 39º 29' 36" N, 00º 27' 56" W. Site Classification: Urban-Suburban Sky darkness: 3.5 <Limiting magnitude> Telescope: Meade 10" LX-200 SCT Magnification: 200x |
Published measures
are the mean of two observations made from two different observers.
d = 35.0; PA = 59
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