| William L. Schart | ||||
| Star:
Zeta Orionis
Date & Time: November, 26th, 1998 - 10:22 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: 32x, 48x, 120x Star: Zeta Orionis Date & Time: 12/26/99 9:10 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, 120x Star: Zeta Orionis
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This is the
left most, or in its current orientation, lower of the "belt" stars. The
primary is bright white, however I was not able to locate the secondary
at any power.
Easily split at 72x. Faintness
of secondary makes it hard to measure, but I figure separation at 50",
PA 175 degrees.
The secondary was very faint, but I was still able to split this at 32x. At 72x, zeta itself appears as a nice blue-white and the companion is blue. Separtion is 60", PA 170 degrees. |
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| Craig M. Carver | ||||
| Star:
Zeta Orionis
Date & Time: 11/27/98 0130 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: 5.1-5.3 <Limiting magnitude> Telescope: 6" Maksutov Magnification: 95x, 190x |
The mag 10 C star is easily split, but I am unable to see the mag 5.5 star at 2.6" from the primary. . | |||
| Paolo Morini | ||||
| Star:
Zeta Orionis
Date & Time: 07 Dec 1998, approx 23 UTC Seeing: 8 <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 eyepiece) Star: Zeta Orionis
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Very fine.
B component is tangent to the diffraction ring of A, clearly visible. No
registered coloration.
Seen all the three components,
but with the bad seeing conditions the two narrowest were somewhat hard.
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| Penny Fisher | ||||
| Star:
Zeta Orionis
Date & Time: 12/11/98 Seeing: 6 <1-10 Seeing Scale (10 best)> Location of site: Englishtown NJ, 40.25 N 74.333 W Site classification: Suburban Sky darkness: 4 <Limiting magnitude> Telescope: 8 inch Dob Magnification: 47x Star: Zeta Orionis Date & Time: January 14th 8 p.m. ET Seeing: 5 <1-10 Seeing Scale (10 best)> Location of site: Englishtown NJ, 40.25 N 74.333 W Site classification: Suburban Sky darkness: 4.0 <Limiting magnitude> Temperature: 10*F Telescope: 8 inch Dob Magnification: 80x (15mm Televue Plossl) |
This was a beautiful double.
The primary star was glowing at 2nd magnitude (it's another of the belt
stars) and was a nice dull white.
The secondary star was several magnitudes fainter, and practically faded out by the much brighter primary. Even through its faintness, I could see it as a very deep blue. Tiny companion star appeared
to occasionally pop out of the diffraction rings of the primary, although
at this magnification and in these windy conditions it was hard to tell.
Maybe I will revisit another night. The stars were both blue, and Alnitak
appears much bluer in the scope views than
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| Dominik Elsässer | ||||
| Star:
Zeta Orionis (Alnitak)
Date: 05.01.99, 21.12-22.05 UT Seeing: 9 Sky Darkness: 4.5 (moonlight) Location: Kleinkahl, Germany Site Classification: Rural Telescope: Vixen 102M Magnification: 250x |
The dim star at 56" was
absolutely no problem. The close companion to the main component is a bit
tricky, because it seldom seems to "break free" from the diffraction rings
of the brighter star. However, today the air was steady enough to allow
for a clean split. The main component appeared to be plain white and
the second star showed a bluish colour in comparison. |
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| Chuck Layton | ||||
| Star:
Zeta Orionis
Date of Observation: Jan. 11, 1999 Time of Observation: 0800 UT Seeing (1 - 10, 10 best): 5 Site classification: Suburban Limiting Mag. (naked eye): 4.8 Instrument Used: 20cm f/6 Eq. Newtonian Magnifications Used: 244X |
Observed Colorations of
Components: All components are bright white.
Other comments: Brilliant white, close AB pair. Difficult to separate due to brightness of primary and magnitude difference. Finally split at 244X. The 10th magnitude C component is easily seen. |
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| Dave Mitsky | ||||
| Star:
Zeta Orionis
Date & Time: 1/27/99 06:20 UT Seeing: 6 <1-10 Seeing Scale (10 best)>. Transparency: ~ 6 Location of site: ASH Naylor Observatory (http://www.msd.org/obs.htm) near Lewisberry, PA Site classification: Rural Sky darkness: < 5.0 <Limiting magnitude> moonlight Telescope: 17" f/15 classical Cassegrain Magnification: 118x, 202x, 259x |
Alnitak, the southeastern
star in Orion's Belt, is a triple with stars of significantly different
magnitudes (2, 5.5, and 10). The close (2.6") AB pair was elongated
but not resolved at 202x as well as 259x. The very wide (57.6") AC pair
was easily split.
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| Orlon Petterson, Marilyn Head, Giles Reid and David Downing | ||||
| Star:
Zeta 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: 208x
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This one I really loved
to see. At 208x I was able to see the primary, the faint companion
off to the north and to my surprise a bright dot in the airy disc of Zeta
Ori. Just outside/on the first ring of the airy disc to the SE was
the other companion! I almost couldn't believe my eyes, this was
a really good challenge for a small refractor.
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| Ilario Melandri | ||||
| Star:
Zeta
Orionis
Date & Time: 6/Dec/1999 – 22.39 UTC Seeing: 5 <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: -0.5C Telescope: 150 mm f/15 achromatic refractor Magnification: 140 x (eyepiece Plossl Clavé 16 mm) |
 |
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| Tomás Vazquez | ||||
| Star:
Zeta Orionis
Date & Time: December, 15, 1999 23:35:10 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: 6 seconds Software used (reading/treatment): Lucas 1.1 / Laia 3.1g Image Position: North up, East left In this image we can observe the main component shining at magnitude 2.0 and the secondary with magnitude 4.1, really easy to split. From the image, we can infere that AP is about 10 degrees. Both components have spectral class O9 - B0 and are located 1,140 light years from us.
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| Richard Harshaw | ||||
| Star:
Zeta Orionis [50 Ori; Alnitak, "the girdle"; STF 774; ADS 4263]
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): 0450 on 12/31/99 Site classification: suburban Sky conditions: seeing-- 6 out of 10 transparency-- 8 out of 10 limiting visual magnitude-- 5 Temperature: 36 F Telescope: Celestron C-8 Eyepiece: 10mm w/ 2.48x Barlow (496x)
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This pair is
too close to measure with my illuminated reticule Micro-Guide so I can
only report visual impressions.
At 496x, I could not pick the companion out of the glare and Airy disk of the primary so I put my hexagonal diffraction mask over the SCT's corrector plate and, abra-cadabra! The companion popped out like a beautiful little gem! This pair is thought to be about 820 light years away, which would make the system as bright as 12,750 Suns. (It seems like everything about Orion boggles the mind!) The German Kunowsky discovered this pair in 1819. (William Herschel missed it!) The pair is probably about 1,280 AU apart. The orbital period may be 1,509 years (Hopmann, 1967). The A star has 18 solar masses and is ejecting mass at 1,800 km/sec; B has 6 solar masses. The diameter of A has been determined by interferometer: 0.00047". Both stars are spectroscopic
binaries, and the B star is an infra-red source.
Measurements from 1990:
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| Rik Hill | ||||
| Star:
Zeta Orionis
Date & Time: UT, 2000-01-05~0700 Seeing: 7-8 (2-3") <1-10 Seeing Scale (10 best)> Location of Site: Location: Jim Loudon Observatory Longitude:110.77554 deg. W or 110 deg. 46' 31.9" Latitude: 32.18006 deg. N or 32 deg. 10' 48.2" Height above sealevel: 2875 ft. see: http://www.lpl.arizona.edu/~rhill/jlobs.html Site Classification: Suburban/Rural Sky darkness: 5.5-6 <Limiting magnitude> Telescope: C11 Magnification: 152x
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Separation
(Clear or Toughing): very clear
Magnitude Comment: Both stars easily seen and 13.7 glimpsed. Color Comment: Primary bl.wht., sec. grey, tertiary too faint for color. General Comment: Similar in appearance to Delta but fainter sec. Some haziness seen esp to east.
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| Patrick J. Anway | ||||
| Star:
Zeta Orionis
Date & Time: January, 7, 2000 04:00 UT Seeing: 5 <1-10 Seeing Scale (10 best)> Location of Site: Munising Michigan USA Site Classification: Rural Sky darkness: 5.8 limiting magnitude Sky condition: No moon. Orion was peaking in and out of clouds Temperature: 15*F -9.4*C Telescope: Zeiss Telementor 63mm, f/13.3 on equatorial mount Magnification: 140X, 210X (Vixen 6mm & 4mm orthoscopics) |
Description:
at 140X they split but not clearly; sometimes appearing
joined together (could have been the tear in my eye from cold). At 210X they split cleanly and were a lovely pair differing in appearance but not color. I thought I would start with
a star that was easy to find; a stud in the
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| Steve Ott | ||||
| Star:
Zeta Orionis
Location of site: Millersburg, KY Date of observations: Jan 9, 2:30 - 4 UT Site classification: Suburban Sky darness: ~ 5.5 <limiting magitude> Seeing: 5 (scale 1-10) Telescope: 94 mm f/7 apo refractor Magnification: 220x |
Fairly easy
at 220X, but ugly image! (discs moving, rings broken) Colors: white
and dirty-yellow.
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| Orlon Petterson | ||||
| Star:
Zeta
Orionis
Date & Time: 12/01/2000, From ~10hr UTC to 11:30 Seeing: 4-7, improved as the evening progressed <1-10 Seeing Scale (10 best)> Location of site: Christchurch, New Zealand Site classification: Suburban Sky darkness: <Limiting magnitude> Telescope: C102HD f/10 refractor Magnification: 28x 50x 100x 208x |
All 3 stars
are visible only at the highest power, with the closer of the 2 companions
being in the first diffraction ring. The closer one was more
easily seen when the scope was stopped down.
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| Bill Becker | ||||
| Star:
Zeta Orionis
Location of site: Casper, Wyoming Elev. 5200' Date of observations: Jan 15th 6:15 UT Site classification: Suburban Seeing: 4 Limiting manitude: 4.5 Telescope: Quantum 4 Maksutov Magnification: 170x |
Saw both companions
this time. Primary seen as white. Close companion's color could not be
determined as primary's brilliance washed out any color it has.Fainter
companion seen as blue. Used 170x
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| Philippe de Jocas | ||||
| Star:
Zeta
Orionis
Date & Time: January 22, 1h00-7h300 UT Seeing: 3-4 <1-10 Seeing Scale (10 best)>. Location of site: Ottawa/Hull, Canada Site classification: Suburban Sky darkness: 4.5 <Limiting magnitude> Temperature: -25C Telescope: 6" f5 newtonian Magnification: 260x |
Ori required all the tools in my arsenal to tackle properly: hexagonal mask, high power (260x, the maximun practical that night), deep breathing and holding very, very steady. But it worked. | |||
| Jordi Viver | ||||
| Star:
Zeta Orionis
Date & Time: 23/01/2000, 23:30 UT Seeing: 7 <1-10 Seeing Scale (10 best)> Location of Site: Vic (Spain) 41º55’N, 2º19’E Elev. 570m Site Classification: Suburban Sky darkness: 5.09 <Limiting magnitude> Temperature: -3ºC Telescope: 200mm self-made Newton, Dobsonian Magnification: 48x |
Separation:
I can see two components, A and C.
Catalog data: Guide 7.0, vM 1.9, 5.5, 9.94. D(A-B)2.6”, D(A-C)58”, PA(A-C)9.7º. General coments: Easy localization. Dificult to separe.
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| John M. Ryan | ||||
| Star:
Zeta
Orionis
Date of Observation: 24/1/00 23:00UT Location of Observation: Ciudad Rodrigo, Salamanca, Spain 40º 36' N, 6º 32'W, Elev. 800 Meters Seeing: 5 (1 - 10, 10 best) Site classification: Urban Limiting Mag. (naked eye): 4 Instrument: TeleVue 101 Apo refractor Magnification: 60x, 180x |
Separation (Clear or Touching):Clear
Magnitude Comment: Observed magnitudes in acordance with the data Color Comment: All components tend to be ovserved as white. General Comment:The wide component is very dim which should be the mag 10 star. Zeta is very bright but I could see the close component the mag 5.5 star apearing and disapearing with the seeing. At 180X the close component was more apparent and stayed in sight more. The rule about close pairs of different magnitues being more difficult to split and observe is apparent in Zeta and its close component. |
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| Jim Brownfield | ||||
| Star:
Zeta
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 Star: Zeta Orionis
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split 9.9 mag star at 47x,
but failed to split 4.0 mag star at any power up to 200x
found 9.9 mag star at 45x, then could make it out at 28x. 4.0 mag star was unresolved up to 187x |
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| Tom Teague | ||||
| Star:
Zeta
Orionis
Date & Time: 2000 January 25-26, 2120UT Seeing: 7 <1-10 Seeing Scale (10 best)>. Location of site: Chester, England (53 11 08N; 02 51 39W) Site classification: Suburban Sky darkness: 4.5 <Limiting magnitude> Telescope: 63mm Zeiss Telementor refractor Magnification: x252 |
Cleanly split, but only
just - in contact during moments of poor seeing. Both stars seem
yellow. PA estimated at 160 degrees. There is a faint third
star in estimated PA 10 degrees. A lovely pair.
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| Richard Bise | ||||
| Star:
Zeta
Orionis
Date & Time: January/29/2000, 8:30 to 10 PM MST Seeing: 6-7 <1-10 Seeing Scale (10 best)> Location of site: 20 miles NW of Tucson Az 32.884N -110.979W Site classification: Suburban Sky darkness: 4 <Limiting magnitude> Telescope: 10 inch Meade Dobsonian Magnification: 49x, 125x (25mm Meade and 9.7mm Plössls) |
This one was easier than
I thought it would be. The companion is far enough removed from the 1.9
magnitude primary to avoid being lost in the glare.
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| Bill Reinehr | ||||
| Star:
Zeta
Orionis
Date & Time: February 4, 2000, 03:30 UTC Seeing: 8 <1-10 Seeing Scale (10 best)> Location of site: Pflugerville, Texas, USA (30 degrees N.) Site classification: Suburban Sky darkness: 4 <Limiting magnitude> Temperature: 64 F. Telescope: Vixen 80mm Fluorite, f/8 on Custom D altaz mount Magnification: 91x, 183x, 256x |
Somewhat clean
but usually touching at 183x. A better split at 256x. 256x was a little
over the top for the viewing conditions, but a clean split was occasionally
observed during moments of better seeing. In addition to better than average
seeing conditions, reading the observation reports of others helped immensely
in pinpointing the location of the cozy component (Thanks!).
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| John Clemmer | ||||
| Star:
Zeta Orionis
Date & Time: Feb 7/200, 2100 EST Seeing: 6, a bit bouncy <1-10 Seeing Scale (10 best)> Location of site: Priceville, Ontario, Canada W80 41'41" N44 10' 40" Site classification: Rural Sky darkness: didn't check lowest vis. magnitude. best would be circa 6.2 <Limiting magnitude> Temperature: -15C Telescope: 4.5" f26 Kutter Schiefspiegler Magnification: 107x (26mm eyepiece) |
107x/clean | |||
| Jay Zimmerman | ||||
| Star:
Zeta Orionis
Date & Time: 02/08/2000, 0445 UT Seeing: 8 <1-10 Seeing Scale (10 best)> Location of Site: Carbondale, IL, USA Site Classification: Suburban/near rural Temperature: 30°F (-1.11°C) Sky darkness: 5.3 <Limiting magnitude> Telescope: 97mm, f7 apo Magnification: 80x, 160x, 192x
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The AC separation
is wide enough for very low power, provided that C (mag. 10) can be seen
at all. I started at 80x where C was clearly visible. Probably could
have gone lower. The AB split required 160x and was much cleaner
and prettier at 192x (8mm EP + barlow). Colors: A and B = white;
C = pale blue.
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| Karl Fabian | ||||
| Star:
Zeta Orionis
Date & Time: Feb17 0300hrs Seeing: 6 to 7 (ALPO scale): . Location of site: Hickory Hills, IL USA 41.7N, 87.8W Site classification: Suburban Sky darkness: 4 <Limiting magnitude> Telescope: 90mm F/11 Achromatic (Meade) Magnification: 200x, 250x |
Very difficult double requiring
good seeing with aperture employed (90mm).
Seen as blip or thickening in diffraction ring during all but the steadiest of moments, when the 4.2 magnitude comes would briefly make an appearance as a seperate component in the correct position angle (without prior knowledge). Seen only with 200x and 250x. Eta Orionis is much easier target.
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| Tim Leese | ||||
| Star:
Zeta Orionis
Date & Time: 19-Feb-2000, 1900-2330 UT. Seeing: 5/6 <1-10 Seeing Scale (10 best)> Location of site: Cheshire. UK 53° 15' N –2º 33' W Site classification: Suburban Sky darkness: 3 <Limiting magnitude> Conditions: High haze, very cold and frosty, sky clearing later but full moon. Telescope: 200mm f/6 Newtonian scope mounted over a Vixen GP mount (manual slow motion). Magnification: x120, x240 Star: Zeta Orionis
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Unable to split
close secondary ( suspect it may lie in the diffraction spikes from the
secondary mirror support). Mag 10 companion observed OK.
At x120, in moments of steady
seeing, the close companion was observed.
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| G.E.O.D.A Group | ||||
| Star:
Zeta Orionis
Date & Time: 10-III-2000, 19:00-21:00 UT Seeing: 7.5 <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 <Limiting magnitude> Telescope: Meade 10" LX-200 SCT Magnification: 200x |
Published measures
are the mean of two observations made from two different observers.
d = 3.8-71.7; PA = 163-12
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