| Richard Harshaw | ||||
| Star:
Alpha Leo [Regulus; 32 Leo; SII 6; Holden 127; ADS 7654]
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): 0500, 01-13-00 LT: 2300, 01-12-00 Site classification: suburban Sky conditions: seeing-- 6 out of 10 transparency-- 5 out of 10 limiting visual magnitude-- 4 Temperature: 28 F Telescope: Celestron C-8 Eyepiece: Micro-Guide (160x) |
Measurements from 1989--
Primary, 1.4 mag, B7V Companion B, 7.7 mag, K1V; 175" at PA 308 (both appear to be fixed) Companion C, 8.5 mag; 81" at PA 163 I made five pairs of separation and PA measures using the Micro-Guide and got an average of 179" at 308 PA. AB first measured in 1836 (177" @ 307); 1960 (178" @ 307). BC first measured in 1835 (81" @ 163). This is an easy triple, with white Regulus ruling over two yellowish companions. C, being fainter than B and closer to Regulus, was difficult to spot, though. Regulus is 5 times the diameter of the Sun and has a surface temperature of 13,000 Kelvins. Its angular diameter is 0.00134". It is also an infra-red source. The orbit with its B companion takes about 2,000 years. Regulus itself is also a spectroscopic binary and spins like the Tasmanian Devil-- 329 kps! This must give it a distinct ellipsoidal shape. Regulus and B make an interesting study in Main Sequence stars. Regulus
is a B7 class while B is a K1. A K1 star would have a surface temperature
of only about 4000 Kelvins (less than a third that of Regulus). B
stars are strong in Helium; K strong in heavy metals.
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| Tom Teague | ||||
| Star:
Alfa Leonis (Regulus)
Date & Time: 2000 February 6-7 (2115 UT) Seeing: 5 <1-10 Seeing Scale (10 best)>. Location of site: Chester, England (53 11 08N; 02 51 39W) Site classification: Suburban Sky darkness: 4 <Limiting magnitude> Telescope: 63mm Zeiss Telementor refractor Magnification: x34, x84, x140, x210 |
Companion easy at all powers. Primary is yellow. No colour for companion
(suspect bluish??).
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| Tim Leese | ||||
| Star:
Alfa Leonis (Regulus)
Date & Time: 25-Feb-2000, 1930-2350 UT Seeing: 4-5 <1-10 Seeing Scale (10 best)> Location of site: Cheshire. UK 53° 15' N –2º 33' W Site classification: Suburban Sky darkness: 3-4 <Limiting magnitude> Conditions: High haze, slight breeze Telescope: 200mm f/6 Newtonian scope mounted over a Vixen GP mount (manual slow motion). Magnification: x96 |
A white blue star observed with mag 8 companion
seen at PA 310 (estimated).
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| Mike Nebelsick | ||||
| Star: Alfa
Leonis (Regulus)
Date & Time: 2000 March 06 (0215 UT) 2000 March 05 (2015 CST) Location of Site: Naperville, IL USA (41d 47m North; 88d 15m West) Site classification: Suburban Temperature: 45 F Seeing: 7 <1-10 Seeing Scale (10 best)> Sky darkness: 4 <Limiting magnitude> Transparency: 5/10 Telescope: Meade ETX90 (90mm Mak-Cas) Magnification: 48x (26mm Super Plossl) |
Very easily wide pair at 48X.
Primary bright white / pure white. Companion much dimmer and appears blue-ish. PA Estimated to be 305. (not measured)
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| Jay Zimmerman | ||||
| Star: Alfa
Leonis (Regulus)
Date & Time: 03/08/00, 0415 UT Seeing: 7-8 <1-10 Seeing Scale (10 best)> Location of Site: Carbondale, IL, USA Site Classification: Suburban/near rural Sky darkness: 5.3 <Limiting magnitude> Temperature: 47°F (8.3°C) Telescope: 97mm, f7 apo Magnification: 13.3x
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Very wide. Amount of separation precludes problems due
to glare or magnitude difference. A = B = blue white.
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| Philippe de Jocas | ||||
| Star:
Alfa Leonis (Regulus)
Date & Time: March 18, 2000 Seeing: 8 <1-10 Seeing Scale (10 best)>. Location of site: Ottawa/Hull, Canada Site classification: Suburban Sky darkness: 4.2-4.3 <Limiting magnitude> Temperature: -10C Telescope: 6" f5 newtonian Magnification: 10x, 40x |
After 1417 and 1413 a relief, best seen at lowest magnification, 40x, and I could even catch it all in my finder at 10x (inspired by Sky and Telescope, I made it from a half of a pair of binoculars). What I found striking was the briliant blue of Regulus itself; by contrast the cpn. appeared a dull yellowish/gey to my eyes. | |||
| William L. Schart | ||||
| Star: Alfa
Leonis (Regulus)
Date & Time: 3/23/2000 7:38 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: Orion 6" Dob. Magnification: 48x, 98x |
Very wide spaced double. The primary was a brilliant blue-white,
but I couldn't tell much about the secondary, as it was over-powered by
Regulus itself. I got a separation of 170', a little short of published
figures, and a PA of 305d, just short of the published 307d.
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| Ilario Melandri | ||||
| Star:
Alpha Leonis (Regulus)
Date & Time: 30 Mar 2000 – 19.04 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: 6 <Limiting magnitude> Temperature: +8C Telescope: 150 mm f/15 achromatic refractor (lens by Romano Zen, Venice) Magnification: 140 x (eyepiece Plossl Clavé 16 mm) |
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| Penny Fisher | ||||
| Star:
Alpha Leonis (Regulus)
Date & Time: 4/1/00 8:30 EDT Seeing: 6 <1-10 Seeing Scale (10 best)> Location of site: Jackson, New Jersey,USA Site classification: Rural Sky darkness: 5.5 <Limiting magnitude> Telescope: Orion 8" Dob. Magnification: 48x |
This was easily split as a double. The primary was a beautiful
clean blue white, with diffraction spikes. The B star was widely
spaced and many magnitudes dimmer (8 or 9?) from the A star. In the same
F.O.V., companion appears grayish-blue.
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| John M. Ryan | ||||
| Star:
Alpha Leonis (Regulus)
Date of Observation: 4/05/00 22:30UT Location of Observation: Ciudad Rodrigo, Salamanca, Spain 40º 36' N, 6º 32'W, Elev. 800 Meters Seeing: 5 to 6 (1 - 10, 10 best) Site classification: Urban Limiting Mag. (naked eye): 5 Instrument: Meade 8"SCT Magnification: 80X |
Separation (Clear or Touching):Clear
Magnitude Comment: Secondary much dimmer in accordance with the data. Color Comment: Alpha Bluish White, secondary dim tending to greyish General Comment: After the beautiful appearance of Algieba, Regulus was a bit of a let down with the very wide separation and dim secondary. However the Bluish white color of Regulus (spec B8) made up for the lack of color to me of the Algieba double. The secondary being dim seemed greyish. Because of the wide separation (177") easy split at 80X. After setting my directions carefully I estimated a PA of 310º which is close to the 307º listed. The practice of estimating the PA as carefully as I can will be good practice when I start using the Celestron Microquide for more precise measurements.
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| Bill Reinehr | ||||
| Star:
Alpha Leonis (Regulus)
Date & Time: April 07, 2000 04:00 UTC Seeing: 6+ (occasional gusts) <1-10 Seeing Scale (10 best)> Location of site: Pflugerville, Texas, USA (30 degrees N.) Site classification: Suburban Sky darkness: 4.0 <Limiting magnitude> Temperature: 65F Telescope: Vixen 80mm Fluorite, f/8 on Custom D altaz mount Magnification: 29x |
Separation: Clear
Comment: Very easy and wide split at 29x. No color noted.
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| Eddy O'Connor | ||||
| Star: Alpha
Leonis (Regulus)
Date & Time: : April 9th 2000, 10 -10.20 p.m. local time.(GMT +10) Seeing: 6 <1-10 Seeing Scale (10 best)> Location of Site: Long.150E; 34 52' S, Australia Site Classification: Suburban Sky darkness: 5 <Limiting magnitude> Instruments: 25X100 binocs, 102mm Vixen Refractor, 8" Dobsonian, 16" uncoated mirror. Magnification: |
Primary and wide secondary seen in all instruments; no
sign of third comes.
Colours: In all instruments, primary appeared greenish white, while secondary was pinkish yellow in 8" only. In other instruments, companion's colour grayish. In Vixen, primary looked like a dazzling Uranus. Ambience: Summer Moon at low altitude obscured by willow tree which
will soon have to be- yet again- severly pruned. Heavy dew a problem. Coal
Sack barely visible and Northern sky glows slightly. Catconfused at I move
from front lawn to back several times testing various
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| Bill Becker | ||||
| Star: Alpha
Leonis (Regulus)
Location of site: Casper, Wyoming Elev. 5200' Date of observations: 12/4/2000 4:05 UT Site classification: Suburban Sky conditions: Seeing: 3 (atmosphere very turbulent) <1-10 Seeing Scale (10 best)> Darkness: 3.5 (Lots of moonlight) <Limiting magnitude> Telescope: Vixen 102 FL Magnification: 51x (Radian 18mm) |
At 51x, Regulus(Spect B7) was of course an easy double
to split. Colour wise, I find Regulus, also known as ADS 7654 ;^), to be
pure white. No colouration was noted in the comes.
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| Rafaello Braga | ||||
| Star: Alpha
Leonis (Regulus)
Date & Time: 22.04.2000, 22.15 UT Seeing: 3 (bad) <1-10 Seeing Scale (10 best)> Location of Site: Corsico, Italy Site Classification: suburban Sky darkness: about 3.5, windy <limiting magnitude> Telescope: 75mm (3") f/6.7 Pentax apo refractor Magnification: 20x (Plossl 25 mm) |
Very easy (176.9 arcsec) at 20x. A yellowish, B pale bluish
(pale purple, following Smith's description). Nice field.
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| Patrick J. Anway | ||||
| Star: Alpha
Leonis (Regulus)
Date & Time: April, 23, 2000 02:00 UT Seeing: 8 <1-10 Seeing Scale (10 best)> Location of Site: Munising Michigan USA Site Classification: Rural Sky darkness: 6 <limiting magnitude> Sky condition: No moon - just below horizon; no clouds Temperature: 28*F -2*C Telescope: Zeiss Telementor 63mm, f/13.3 on equatorial mount Magnification: 34x, 168X (Vixen 25mm and 5mm orthoscopics) |
Easily split at 34X with primary being a brilliant white
and the secondary an off-white, almost gray. According to Olcott in his
book "Star Lore of All ages" Regulus has been known as "Star Royal" or
"the Kingly Star". Fittingly it is Leo the lion, the most royal of constellations
in the Zodiac. In his book "In Starland with a Three-Inch Scope" Olcott
quotes Agnes Clerk as saying the companion is "seemingly steeped in indigo".
I looked carefully to see any blue, but could not. An interesting comment
in his "Field Book of the Skies" states that the companion is "a difficult
object for a 3 inch scope." I had no trouble viewing it with a 2.5". Love
those modern coatings!
Split cleanly at 168X with both stars being golden in color; the primary showing more yellow. A truly beautiful pair which might rate Louis' award of the same color. Struve called it "the finest double in the northern sky" and who is going to argue with him! |
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| Alessandro Bertoglio | ||||
| Star: Alpha
Leonis (Regulus)
Date & Time: April, 25, 2000, 19.53 UT Seeing: 8 (Pickering A) Location of Site: Turin - Italy Site Classification: urban Sky darkness: 4 - 4.5 <limiting magnitude> Telescope: 120mm, f=1800mm achromatic refractor Magnification: 185x (Meade PL 9.7 mm) |
Very easy double star with high magnitude difference.
Regulus A presents a strange slightly yellowish colour and not a bluish white tone as reported by some authors. Presents 2 strong rings and the typical bluish halo due to secondary spectrum of my refractor. The second ring is complete but in movement. Regulus B has a well visible first ring. The other star “C” is not visible (Turin light and pollution are the cause of this fact). Estimated PA = 305°
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