Few bazooka stats. I need to remember these during future observations.
Celestron StarHopper 6 Dobsonian
Aperture: 6 inches / ~15 cm / 150 mm
Focal Length: 1219 mm (F/8)
Celestron Plossl Eyepiece: 32mm, 15mm, 6mm and 2x Barlow.
Apparent Field of View (AFOV): 52 deg for all. 44 deg for 32mm
Eye Relief: ?????
Magnification: Telescope focal length / Eyepiece focal length
Eyepiece 32 mm : 38x (1219mm/32mm)
Eyepiece 25 mm : 48x (1219mm/25mm)
Eyepiece 12.5 mm : 97x (1219mm/12.5mm)
Exit Pupil: Telescope aperture / Magnification
Eyepiece 32 mm : 3.9 mm (150mm/38x)
Eyepiece 25 mm : 3.1 mm (150mm/48x)
Eyepiece 12.5 mm : 1.5 mm (150mm/97x)
True field of view (TFOV): Apparent field of view (AFOV)/ Magnification
Eyepiece 32 mm : 1.16 deg (44deg/38x)
Eyepiece 25 mm : 1.08 deg (52deg/48x)
Eyepiece 12.5 mm : 0.54 deg (52deg/97x)
Maximum that can be supported on this telescope:
Max Exit Pupil : ~6 mm : Mag 25x (150mm/6mm) : Focal Length 48mm (1219mm/25x)
Min Exit Pupil : ~0.5 mm : Mag 300x (150mm/0.5mm) : Focal Length 4mm (1219mm/300x)
Best Exit Pupil : 2 mm : Mag 75x (150mm/2mm) : Focal Length 16mm (1219mm/75x)
Nikon 10x50 Binocular:
Field of View: 6.64 deg : 114m at 1000m
Exit Pupil: 5.0
Eye Relief: 17.2
Wednesday, March 19, 2008
Thursday, March 13, 2008
India Trip - 26th Jan 2008
During my India Trip, after landing at bombay airport, while driving from Bombay to Pune at 5:30 am, I saw an amazing pair of two bright stars (?) in eastern sky.. At that time I wasn't aware what I was looking at.. Near the constellation of scorpio, these two stars (?) around 5 deg apart, were the brightest in the sky. I was guessing who they were.. and it tuned out to be.. Jupiter and Venus in conjunction... marvelous event to witness..
This celestial event indeed marked the beginning of my India Trip :)
(Photo credit: APOD - 2nd Feb 2008)
This celestial event indeed marked the beginning of my India Trip :)
(Photo credit: APOD - 2nd Feb 2008)
Saturday, March 8, 2008
SD Home - 8th March 2008
Date: 8th March 2008, Saturday
Observation Time : 7pm to 8:05pm (1:05 hrs)
Location : Home Patio, SD CA
Seeing : Okay
Transparency : Okay
Cloud Cover : Somewhat
Instrument : My 6' dob
Highlight of the night: M42 - Great Orion Nebula
I took out my dob today, probably after 5 months. Until now, because of bad weather in SD, I really didn't get a chance to observe anything... but today, finally, I made my first observation of this year.
It was somewhat cloudy. From my patio, only SW sky is visible.. so some part of Orion and whole Canis Major was visible. so obviously the first choice was M42.
Its first time I observed M42 from my dob., since I bought it. Being the brightest nebula in the sky, I had high hopes.... and indeed..it didn't disappoint me. Observed through 35mm and 2x barlow eyepiece .
Initially M42 looked like a cloud, but more my eyes set on it, the true shape was visible. The dish structure - "wings" are truly awesome.. The "fish mouth" was dark and pretty big than I expected. 3 bright stars on SE are parallel to "fish moth". The Trapezium cluster at the top of the "fish mouth" is striking. I was easily able to resolve stars A,C,D, B .. From my 10x50 binocs, I guess I have seen only C star (not sure abt D) , but with the 6" dob, without any mistake the trapezium was visible. On SW of "fish mouth" another protruding dark tower is visible (don't know the name)..somewhat perpendicular to "fish mouth"and 1/3 rd in size. At SE of this tower there is bright a star hanging.
(Photo credit:.. from net somewhere.. the "visual" image is somewhat similar to what I saw, but I had clear and zoomed view..)
Had some focusing problem with the dob.. Stars weren't visible as precise points.. probably some parallax.. need to do some alignment.
Missed M43, at NE corner of M42... next time !!
Sirius was beautiful... like a big diamond.. because of clouds (or probably optics), there was some diffraction of light, causing visual of rays spreading out from Sirius.. it indeed gave me a feeling of "Tanishque / Jared" diamond... simply fabulous :) .... I wasn't aware that Sirius is a double star, but difficult to resolve... still.. will try it next time !!
M41 open cluster in Canis Major was easy catch. Its around 5 deg south of Sirius. Seems like it has ~50 stars, with lots of them in pairs. Wasn't able to resolve their colors.. but some of them seem to be reddish.. not sure.. In order to remember it, I tried to visualize some shape in the star cluster... Bright stars in the cluster seemed like forming a shape "E" with central line extended backwards, like a 3 pronged fork.. or its like a small "Trishul".
Any way... didn't spend much time today.. only 45 mins.. but surely a good start for year 2008... was planning for Messier Marathon at TDS today.. but weather sort of disappointed me..
Interesting Links:
- M42 at SEDS
- M42 sketches It looked somewhat similar from my 6" dob.
- Trapezium Cluster
- M42 Regional map
Observation Time : 7pm to 8:05pm (1:05 hrs)
Location : Home Patio, SD CA
Seeing : Okay
Transparency : Okay
Cloud Cover : Somewhat
Instrument : My 6' dob
Highlight of the night: M42 - Great Orion Nebula
I took out my dob today, probably after 5 months. Until now, because of bad weather in SD, I really didn't get a chance to observe anything... but today, finally, I made my first observation of this year.
It was somewhat cloudy. From my patio, only SW sky is visible.. so some part of Orion and whole Canis Major was visible. so obviously the first choice was M42.
Its first time I observed M42 from my dob., since I bought it. Being the brightest nebula in the sky, I had high hopes.... and indeed..it didn't disappoint me. Observed through 35mm and 2x barlow eyepiece .
Initially M42 looked like a cloud, but more my eyes set on it, the true shape was visible. The dish structure - "wings" are truly awesome.. The "fish mouth" was dark and pretty big than I expected. 3 bright stars on SE are parallel to "fish moth". The Trapezium cluster at the top of the "fish mouth" is striking. I was easily able to resolve stars A,C,D, B .. From my 10x50 binocs, I guess I have seen only C star (not sure abt D) , but with the 6" dob, without any mistake the trapezium was visible. On SW of "fish mouth" another protruding dark tower is visible (don't know the name)..somewhat perpendicular to "fish mouth"and 1/3 rd in size. At SE of this tower there is bright a star hanging.(Photo credit:.. from net somewhere.. the "visual" image is somewhat similar to what I saw, but I had clear and zoomed view..)
Had some focusing problem with the dob.. Stars weren't visible as precise points.. probably some parallax.. need to do some alignment.
Missed M43, at NE corner of M42... next time !!
Sirius was beautiful... like a big diamond.. because of clouds (or probably optics), there was some diffraction of light, causing visual of rays spreading out from Sirius.. it indeed gave me a feeling of "Tanishque / Jared" diamond... simply fabulous :) .... I wasn't aware that Sirius is a double star, but difficult to resolve... still.. will try it next time !!
M41 open cluster in Canis Major was easy catch. Its around 5 deg south of Sirius. Seems like it has ~50 stars, with lots of them in pairs. Wasn't able to resolve their colors.. but some of them seem to be reddish.. not sure.. In order to remember it, I tried to visualize some shape in the star cluster... Bright stars in the cluster seemed like forming a shape "E" with central line extended backwards, like a 3 pronged fork.. or its like a small "Trishul".
Any way... didn't spend much time today.. only 45 mins.. but surely a good start for year 2008... was planning for Messier Marathon at TDS today.. but weather sort of disappointed me..
Interesting Links:
- M42 at SEDS
- M42 sketches It looked somewhat similar from my 6" dob.
- Trapezium Cluster
- M42 Regional map
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