How to observe the Cone Nebula?
Posted 12 October 2013 - 08:05 PM
How much magnification is needed? And is a filter necessary? If so, what kind?
Thanks in advance for any advice,
Roy in Taos
Posted 12 October 2013 - 10:53 PM
At such low surface brightness and contrast, you may need to have the feature you desire to see subtend several degrees on the retina in order to detect it. Find out the Cone's width, then calculate the magnification required to bring it up to, oh, 5 degrees. If we take a width of 4 arcminutes, to subtend 5 degrees requires a magnification of 75X. If a narrow band filter is employed, the exit pupil should be at least 4mm, implying an aperture of at least 300mm (at 75X.)
Posted 13 October 2013 - 12:45 PM
And with binoculars, it´s possible?
No, it is somewhat small in scale and too faint to be seen in most binoculars (unless maybe you are using a pair of large Newtonian telescopes in some sort of "binocular" configuration). I have seen it (barely) in a 10 inch Newtonian on a superb night when using a narrow-band nebula filter (Lumicon UHC), but it was still pretty marginal. In my 14 inch Newtonian, I have seen it a few more times, but it still is more of a vague darkening of the sky background extending to the south from a faint pair of stars than anything else. In larger apertures, the H-beta filter may provide a bit more contrast than the narrow-band filters will, but the "cone" is still a very difficult target visually (notably harder to see than the Horsehead is). Clear skies to you.
Posted 14 October 2013 - 05:31 AM
I would like to know if it is possible to obtain a good visual observation of the Cone Nebula, which is part of NGC2264, the "Christmas Tree" cluster in Monoceros.
I agree with others here that this is an extremely difficult object to observe. I have never obtained a view that really satisfied me.
For the record, the Cone is technically the dark indentation on the south side of the bright nebula. The bright nebula is huge, and seems almost hopeless to detect in its entirety since it is mixed with a rich Milky Way field on the northwest.
Posted 14 October 2013 - 05:57 AM
Posted 14 October 2013 - 02:57 PM