HN 40

Richard Harshaw
Star: HN 40
Date & Time: Late 1980's
Seeing: 7 <1-10 Seeing Scale (10 best)>. 
Transparency: 7/10 
Location of site: Columbia, USA 
39º 30m N,  ~ 90º W
Site classification: Suburban
Sky darkness:  <Limiting magnitude> 
Telescope: Celestron C8 SCT 
Eyepieces: --
Magnification: --
Historical observation. Not from the official period for this project. 

A nice triple (the C star is cataloged as H N 6), located at 1802-2302.  The primary (O7 giant) is 7.2m and was seen at 207x as white.  The B star is 10.7m and is 5" away in PA 22.  It was too faint to get a color.  The C star is 8.7m and is 11" away in PA 210 and was seen as white.  (There is also a faint companion to C, listed as "c"; it is 10.7m and is only 2" from C and PA 281.  I saw it but could not get a color estimate on it.)  The A-B pair shares common proper motion.  Distance is unknown.  I rated it 2 on my scale.
 
 
 

 


 
Eddy O'connor
Star: HN 40
Date & Time: July 18th  2001, 7.30 -9p.m local; UT +9
Seeing: 7 <1-10 Seeing Scale (10 best)>. 
Transparency: 7/10 
Location of site: Terara, New South Wales, Australia
Long.150º.38 ; Dec. S 34º.52. 
Temperature. 7ºC
Site classification: Suburban
Sky darkness:  <Limiting magnitude> 
Telescope: 8" Newt. F9 
Eyepieces: 25mm K, 12.5 mm ortho
Magnification: 73x, 146x
Harshaw Scale: 1 <1-5; 1 best>
Mag. 7/8/10.5, Sep10.6"/5.4". This is the easiest and most rewarding triple star in Sagittarius. It holds the Dress Circle position in the famous Trifed Nebula(M20) and dominated this field. The Primary star is a Pearly White and it is flanked by a Light Blue star SW and deeper and fainter third companion  NE all in a row in a darkened sliver of sky. The mottled curtain-like nebulosity of the Trifed enfolds the area making this a magnificent view at low power. Hartung has observed a fourth star in the group with a 20cm mirror and a fifth star with 30 cm. HS1

Ambience: This was another wonderful night of observing with light wind which only increased as I finished. A late departing skein of swans passed overhead, their plaintive cry in strange contrast to the totally quiet landscape under the glowing Milky Way.  I noticed a slight change in Uranus's position and Neptune surprised me by presenting a delightful and contrasting wide double of 4" separation with Upsilon Capricorn which it is passing during the coming days. 

 
 
Luis Argüelles
Star: HN 40
Date & Time: 24th, July, 2001. 21:45 UT
Seeing: 5.5 <1-10 Seeing Scale (10 best)>
Transparency: 5-6 <0:worst -10:best >
Location of site: Quintueles, Gijón, Spain.  43º 32N, 5º 55W. Altitude: 20 m.
Site classification: Suburban
Sky darkness: 3.5 <Limiting magnitude> 
Temperature: about 19º C
Conditions: A lot of haze and moisture. Seeing is not bad at all, but haze actuates like a light diffusor and that makes difficult observe stars fainter that 10
magnitude.
Humidity: about 90%
Telescope: Vixen 102 4" achromatic refractor
Eyepieces: Eudiascopic 35mm, Zeiss Ortho 10mm
Magnification: 28x, 100x
Harschaw Scale: 3 <From 1 to 5. 1 = Great, 5 = poor interest>
   
With the observing conditions this is not a remarkable double. At only 28x, but with difficulty, the "first" split is appreciable. Going up to 100x it's clearly identified as a triple system, converting M20 in a Nebula with surprise!