Quote:
Originally Posted by leinad
Seeing 8/10
Centaurus
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NGC 5129 (Omega Centauri)
Definately a favourite starter for the night.
Clear pins of light. Large ball of star luminance
NGC 5128 (Centaurus A)
Took a little while to find. Using Telrad I was able to find it 8degrees left of NGC 5129, and 8degrees above Mu Centauri.
Three times was able to locate Cent A successfully.
Using averted vision was able to see the dark lane between the galaxy glow, slighty elongated.
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Hi,
Nice report. Sounds like you had a fun nights observing.
I can appreciate you are only learning so I have a couple of tips which may help you for future observing sessions.
1) Omega Centauri = NGC 5139
You mention above, "you found Centaurus A 8 degrees left of Omega Centauri". NGC 5128 (Centaurus A) is in fact 4.5 degrees "NORTH" of NGC 5139 (Omega Centauri).
This raises two things you need to focus on as you learn the sky.
1) Left, Right, Up and Down are poor terms to use for orientation. This becomes particularly critical as you get closer to the Celestial Poles. The closer to the pole, the faster things change orientation. For instance at 10:00pm something may be "left", but at 1:00am it is "up". Even with a constellation like Centaurus which is near the Celestial Equator, the orientation of left to right changes as Centaurus crosses the Meridian. In respect of the 2 targets you refer to, if you look at their positions at 6 am, you will find that Centaurus A is to the right of Omega Centauri, not to its left like it is earlier in the evening. You should try to learn the north, south, east and west orientations in the sky as these remain static, irrespective of time. They take a little understanding to begin with, but persevere.
2) You mention a separation of "8" degrees between the 2 targets when in fact it is 4.5 degrees. You need to check your finderscope/telrad scales and your sky estimates to get this a little more accurate as it will allow you to find the targets a lot quicker and with a lot less frustration. There is nothing worse than spending all night under beautiful dark sky conditions, having trouble finding things. A good rule of thumb for measuring sky distances is:-
With arm extended to its normal full extension:-
Closed fist = about 10 degrees
Middle 3 fingers = about 5 degrees
Index finger = 1 degree.
Of course people have different sized hands and different arm lengths but the above is a "reasonable" guesstimate.
Keep up the good work !!
Cheers,
John B