| William L. Schart | ||||
| Star:
Eta Orionis
Date & Time: November, 11th, 1998 - 12:08 am 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 <Limiting magnitude> Telescope: Orion 6" Dob. Magnification: 48x, 72x, 120x Star: Eta Orionis
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This star is
barely visible naked-eye and thus easily found. The primary is a blue-white
while the secondary too faint for color.
Like the list says, easy
to fing but hard to split. Elongated only at 240X.
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| Chuck Layton | ||||
| Star:
Eta Orionis
Date & Time: Dec.20, 1998, 06:00 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: 271x |
Observed Colorations of
Components: Both components appeared blue white.
Other comments: A strong, icy wind made this very close triple tough to separate. I had to wait for lulls. The C component is quite distant from the A/B pair. |
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| Paolo Morini | ||||
| Star:
Eta Orionis
Date & Time: 15 Jan 1999, 21:30 UTC Seeing: 7 <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) Star: Eta Orionis
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Clearly split,
2nd component over the diffraction ring of the main one.
Splitting this star was rather
difficult because of the poor seeing
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| Dave Mitsky | ||||
| Star:
Eta Orionis
Date & Time: 1/19/99 03:55 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, 249x, 381x |
Resolved sporadically at 249x this very close pair (1.5") of 4th and 5th magnitude stars had an almost east-west orientation (77 degree position angle). The primary is a blue-white B0 star. | |||
| Orlon Peterson, Marilyn Head, Giles Reid and David Downing | ||||
| Star:
Eta 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 |
At 208x I was just able to split these 2, with a sliver of black between them. This was another pleasing double to observe with the airy discs around the 2 stars. | |||
| Bill Geertsen | ||||
| Star:
Eta Orionis
Date & Time: December 4,1999 Seeing: 8 Location: Steppingstone Museum parking lot, Bel Air, Maryland. Reasonably dark sky site Instrument: 4" f/9.8 achromatic refractor on a motorized GEM Sky darkness: 5.5 Magnification: 350x |
Description: Both appeared off white, obvious magnitude difference, almost touching, comes inside first diffraction ring. | |||
| Ilario Melandri | ||||
| Star:
Eta
Orionis
Date & Time: 6/Dec/1999 – 19.16 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: --- Telescope: 150 mm f/15 achromatic refractor Magnification: 140 x (eyepiece Plossl Clavé 16 mm) |
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| Richard Harshaw | ||||
| Star:
Eta Orionis [28 Ori; Saif; Dawes 5; AC = H VI 67; ADS 4002; SAO 132071]
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) |
A beautiful
pair! I noted colors of White (B0IV+B2e spectroscopic binary, with
7.9841 day period), deep blue and maybe white??
The system may be 900 light
years away, which would mean the system is as bright as 2750 Suns.
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| Randall Heckman | ||||
| Star:
Eta Orionis
Date & Time: 12/30/99 at 2:25 UT Seeing: 6 Location of Site: Heckman Observatory 40 37' 10" N and 99 03' 50" W Site Classification: Rural Sky Darkness (Limiting Magnitude): 3 Telescope: 8" Orion Dob with 6" aperture mask Magnification: 120x |
Separation (Clear or Toughing):
Clear
Magnitude Comment: Secondary slightly dimmer Color Comment: Colorless General Comment: The sky had become slightly hazy and the seeing improved dramatically. Eta would be difficult to split with the kind of seeing we frequently have in south central Nebraska.
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| Thad Robosson | ||||
| Star:
Eta Orionis
Date & Time: 12-30-99, 3:00 to 6:30 UT (12-31-99 UT) Seeing: 4-5 <1-10 Seeing Scale (10 best)> Location of Site: Carbondale, IL, USA Site Classification: Suburban/near rural Sky darkness: 4.7 using "stars counted in the area of" method, (Taurus) <Limiting magnitude> Telescope: 8" f/6 Newt on Dob mount (soon to be split ring :-) Magnification: 174x |
A stunning
double white pair. Split/notched at 174x
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| Allen Ginzburg | ||||
| Star:
Eta Orionis
Date & Time: 01/03/2000, 04:27 UTC Seeing: 8 <1-10 Seeing Scale (10 best)> Location of Site: Aptos, CA (USA) Site Classification: Suburban Sky darkness: 4 <Limiting magnitude> Telescope: Televue 85mm Magnification: 240x
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The stars overlapped,
but were clearly visible as a double. The primary was blue/white
in color, the secondary yellowish. I was amazed that this was visible
in an 85mm scope, being that the separation is below the limit for this
aperture. I verified the approximate PA later, just to make sure
it wasn't just a visual artifact, and it wasn't. I was surprised
that the color of the secondary was evident.
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| Jay Zimmerman | ||||
| Star:
Eta Orionis
Date & Time: 2300 01/05/2000 CST; 0500 01/06/2000 UT Seeing: 8 to 9 <1-10 Seeing Scale (10 best)> Location of Site: Carbondale, IL, USA Site Classification: Suburban/near rural Sky darkness: ~5 <Limiting magnitude> Telescope: 97mm, f7 apo Magnification: 256x, 384x
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Comments:
At 256x the star was clearly peanut-shaped (smaller nut to the east).
A narrow black strip of sky developed between A and B for a second or two
at a time as the star drifted across the field, attesting to good but less-than-perfect
seeing conditions. Much the same occurred at 384x (on and off clear separation)
but images were degraded (fuzzier) owing to very high magnification for
the aperture. Estimated PA: 80 degrees (actual: 77 degrees). Colors: A
= white; B seemed very slightly yellow, but this may have been an illusion.
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| Giuseppe Bandini | ||||
| Star:
Eta
Orionis
Date & Time: 5/Jan/2000 - 21.10 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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| Steve Ott | ||||
| Star:
Eta Orionis
Location of site: Millersburg, KY Date of observations: Jan 9, 2:30 - 4 UT Site classification: Suburban Sky darness: ~ 5.5 <limiting magnitude> Seeing: 5 (scale 1-10) Telescope: 94 mm f/7 apo refractor Magnification: 220x |
Pretty easy
at 220X. Space between them not always well-defined. Primary white,
secondary pale orange (reminded me for all the world of vanilla and orange
sherbet ice cream).
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| Orlon Petterson | ||||
| Star:
Eta
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 |
Just split
at 208x and most definite when observed at 416x. Most of the
time appeared peanut shaped before being split. Secondary noticibly
fainter.
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| John M. Ryan | ||||
| Star:
Eta
Orionis
Date of Observation: 24/1/00 22:00UT 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: 30x, 60x, 180x |
Separation (Clear or Touching):
Clear
Magnitude Comment: Primary about 2 1/2 times brighter than secondary as noted in the data listed. Color Comment:Both components appeared white General Comment: I was surprised that I could split this close double at 30X. At 60X it was clearer. At 180X it was too dark and not very clear which shows that there are optimum magnifications for each double which is something that I am learning. A very nice double.
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| Jim Brownfield | ||||
| Star:
Eta
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: 200x |
split at 200x with mask, dim star following the brighter | |||
| Tom Teague | ||||
| Star:
Eta
Orionis
Date & Time: 2000 January 25-26, 2100UT 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: x140, x252 |
A magnificent sight x252.
Two discs that seem to overlap, with the fainter one appearing to protrude
from behind the primary as a broad crescent (this is, of course, an illusion).
x140, the secondary appears as a faint extension on the primary, making
it look pear-shaped in estimated PA 80 degrees. No colours (companion
seems greyish). Best view x252.
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| Bill Becker | ||||
| Star:
Eta Orionis
Location of site: Casper, Wyoming Elev. 5200' Date of observations: Jan 31 3:05 UT Site classification: Suburban Sky conditions: Seeing: 4 Darkness: 5 Telescope: Quantum 4 Maksutov Magnification: 85x, 149x |
Looking at
this star at 85x, I couldn't be sure if I saw elongation; boosting the
power to 149x and, yes, during steadier moments, I could detect the peanut
shape to it. The small bulge seemed to point fairly close to 90*. White
dominated the coloring of this double.
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| John Clemmer | ||||
| Star:
Eta
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: 160x, 17mm eyepiece. |
160x/ seen in diffraction ring | |||
| Karl Fabian | ||||
| Star:
Eta
Orionis
Date & Time: Feb 17,2000, 0350hrs 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: 143x, 200x, 250x |
This double was just perceived
at 143x. Lower powers would not show it with certainty. At 200x the comes
was plainly seen, although still very close. During steady moments 250x
gave excellent views with dark sky between the components. PA of 80 deg
correctly determined from view witout prior knowledge.
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| Bill Reinehr | ||||
| Star:
Eta
Orionis
Date & Time: February 26, 2000, 02:30 UTC Seeing: 8 (pretty still) <1-10 Seeing Scale (10 best)> Location of site: Pflugerville, Texas, USA (30 degrees N.) Site classification: Suburban Sky darkness: 4 <Limiting magnitude> Temperature: 67 F. Telescope: Vixen 80mm Fluorite, f/8 on Custom D altaz mount Magnification: : 29x, 91x, 183x, 256x. |
Possible elongation
at 91x but cannot confirm. At 183x two components were very clearly visible
and barely touching. Conditions were beginning to fluctuate and would not
support 256x.
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| G.E.O.D.A Group | ||||
| Star:
Eta 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 = 2.7; PA = 77
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| William L. Schart | ||||
| Star:
Eta
Orionis
Date & Time: 2/24/01 9:37 pm CST Seeing: 6 <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: Celestar 8” SCT Magnification: 78x, 120x, 203x |
I got an elongation
on this. The best view seemed to be at the lower power, where it appeared
peanut shaped and bright blue. Perhaps withm better seeing I could get
a clean split.
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| Otto Piechowski | ||||
| Star:
Eta
Orionis
Date & Time: Sunday, February 25, 2001 8 to 10 pm EST Seeing: 7 <1-10 Seeing Scale (10 best)> Location of site: Lexington, Kentucky, USA Site classification: Suburban Sky darkness: <Limiting magnitude> Conditions: Clear, deep sky, still, fairly steady sky Telescope: 150 mm mak-cass Magnification: 257X, 360X (7 and 5 mm orthoscopic eyepieces) |
Easily resolved
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