Four double stars in Crux
by Magda Streicher
Site and telescope details.
Site: Pietersburg SA – Long: 29°28’ East – Lat: 23o54’ South – Altitude 1311 meters.
Site: Alldays SA – Long: 20°07’ East – Lat: 22o30’ South – Altitude 767 meters.
Telescope: 16 inch Schmidt-Cassegrain – Focal Length 4064mm (f10)
Eyepiece: 2” – Ultra Wide 40mm – 102x – 31.7arc min. FOV
Eyepiece: 2” – Ultra Wide 32mm – 127x – 26arc min. FOV
Eyepiece: 2” – Ultra Wide 14mm – 290x – 17.4arc min. FOV
Eyepiece: 2” – Ultra Wide 8.8mm – 462x – 10.9arc min. FOV
Site: Alldays SA – Long: 20°07’ East – Lat: 22o30’ South – Altitude 767 meters.
Telescope: 12 inch Schmidt-Cassegrain – Focal Length 3048mm (f/10)
Eyepiece: 2” – Ultra Wide 40mm – 76x – 52.8arc min. FOV
Eyepiece: 2” – Ultra Wide 14mm – 218x – 23.1arc min. FOV
Eyepiece: 2” – Ultra Wide 8.8mm – 346x – 14.6arc min. FOV
ADD: 16-inch – 1 division with metric eyepiece calculate for the 16-inch is 6.3” using a 1 ¾ eyepiece
A 117 – Double star – Crux
RA: 12h04m08s – DEC: -62o00’
Magnitude of stars: 7.7 and 8.1 and C 10.2 – 1918 last observe
Separation: 23” and C 25” – Position Angle: 149 – 18
Telescope: 12” Schmidt-Cassegrain 3048mm f/10 – Date: 09.05.2006
Eyepiece: 2” – 32mm Super wide: – 95X – Eyepiece: 2” – 14mm Ultra Wide: – 218X
The primary displays a subtle grey in contrast to the dirty yellow. The C companion looks a dirty white. Very busy star-field.
Revisit:
Telescope: 16 inch Schmidt-Cassegrain – Focal Length 4064mm (f10) – Date: 24.03.2014
Eyepiece: 2” – Ultra Wide 40mm – 102X – Eyepiece: 2” – Ultra Wide 14mm – 290X
Eyepiece: 1 ¾ – 5mm – 812X – plus the use of a Metric Eyepiece – 1 segment on 16-inch Tel: = 6.3”
The lovely pair with the indicted magnitudes is easy to spot. The secondary shines in a deep yellow color. The difference between them (4 divisions – 25”). The C component with the estimate of 10+ magnitude is perhaps change slightly to a PA 325 as measure in line from the primary and against the stars in the field which I pay much attention too. A faint star more or less 13 magnitude was spotted in a PA 130 (9 divisions – 56”) more or less, as measure from the primary. It was difficult to hold the star which indicates a very faint star.
**
BrsO 8 – Double star – Crux
RA: 12h24m08s – DEC: -58o07’
Magnitude of stars: 7.6 and 7.9 – Separation: 5.3” – Position Angle: 335 – 1943 last observe
Telescope: 12” Schmidt-Cassegrain 3048mm f/10 – Date: 09.05.2006
Eyepiece: 2” – 32mm Super wide: – 95X – 14mm Ultra Wide: – 218X – 2” – 8mm Ultra Wide: – 346X
Two very close pairs, the primary a dark yellow to orange with the companion a grey white. Faint stars dotted the west of the star-field.
Revisit:
Telescope: 16 inch Schmidt-Cassegrain – Focal Length 4064mm (f10) – Date: 24.03.2014
Eyepiece: 2” – Ultra Wide 40mm – 102X – Eyepiece: 2” – Ultra Wide 14mm – 290X
Eyepiece: 1 ¾ – 5mm – 812X – plus the use of a Metric Eyepiece – 1 segment on 16-inch Tel: = 6.3”
No change, measure against the star field, show a PA of 338 more or less, but it is so little perhaps same as indicated PA. The primary is a very dark yellow show a hint of orange with a yellow companion. The separation of the two stars as measure with the metric eyepiece is close to 1 division. What I appreciate here is the cluster NGC 4337 which is a lovely open cluster with various magnitude stars in a sort of arrow shape pointing west.
**
h 4548 – Double star – Crux
RA: 12h46m04s – DEC: -56o29’
Magnitude of stars: 4.7 and 9 – Separation: 52.6” Position angle:169 – 1913 last observe
Telescope: 12” Schmidt-Cassegrain 3048mm f/10 – Date: 09.05.2006
Eyepiece: 2” – 40mm Super Wide: – 76X – Eyepiece: 2” – 32mm Super wide: – 95X
Both shine white. A string of four faint stars north-east in the field of view.
Revisit:
Telescope: 16 inch Schmidt-Cassegrain – Focal Length 4064mm (f10) – Date: 24.03.2014
Eyepiece: 2” – Ultra Wide 40mm – 102X – Eyepiece: 2” – Ultra Wide 14mm – 290X
Eyepiece: 1 ¾ – 5mm – 812X – plus the use of a Metric Eyepiece – 1 segment on 16-inch Tel: = 6.3”
The pair quite outstanding , I found however that the primary is much more yellow in color with the estimate companion in a yellow-white color. It amaze me to discovered the change in color (will go back to this one to confirm the color . The PA seems to be correct. A third star 9 magnitude to the west but I pick up a double star estimate around 12.5 to 13 magnitude in a PA of 165 about 160” away.
**
HdO 221 – Crux
RA: 12h55m09s – DEC: -56o50’
Magnitude of stars: 5.3 and 10.3
Separation: 29.1” – Position Angle: 315 – 1913 last observe
Telescope: 12” Schmidt-Cassegrain 3048mm f/10 – Date: 09.05.2006
Eyepiece: 2” – 40mm Super Wide: – 76X – Eyepiece: 2” – 32mm Super wide: – 95X
Eyepiece: 2” – 14mm Ultra Wide: – 218Xx
Just 22arc min. to the north of M1 and 2 the HdO 221 double can be seen. This primary displays a dirty blue with a white companion. Just west outside the field of view a triangle of seven 8 mnitudeag. stars point towards the double.
Revisit:
Telescope: 16 inch Schmidt-Cassegrain – Focal Length 4064mm (f10) – Date: 24.03.2014
Eyepiece: 2” – Ultra Wide 40mm – 102X – Eyepiece: 2” – Ultra Wide 14mm – 290X
Eyepiece: 1 ¾ – 5mm – 812X – plus the use of a Metric Eyepiece – 1 segment on 16-inch Tel: = 6.3”
Very busy star-field, no change as PA and color concern.
**