Starship Asterisk*

Double, double toil and trouble - Gimmi Ratto and Davide Bardini had to suffer a lot of toil and trouble to collect enough light to produce this very fine picture of the Witch Head Nebula. Congratulations on having your picture chosen as a well-deserved Astronomy Picture of the Day!

Ann+

My guess is that this nebula will be very hard to observe.

Since the nebula is a reflection nebula, it reflects much of the light that hits it more or less equally. Admittedly it reflects blue light far better than red light. That still leaves a broad range of wavelengths that are reflected by this nebula. You may try to use an OIII or an H beta filter, which will let through some of the blue-green light from the nebula and block a lot of the background light, but you will still miss a lot of the light from the nebula this way.

A wide wavelength blue filter might be the best, if there are any such filters. But a problem is that many of the stars in the vicinity are blue themselves, and the blue filter will let through most of their light. So the light from the stars will overwhelm the light of the nebula, which is fairly faint anyway.

Ann

neufer wrote:

KCM wrote:
So if the nebula is reflecting blue light, what type of filter would be helpful to observe the Nebula? Or is any necessary?

You want to let light in NOT reduce it.

So why would a filter be necessary (or even desired)?

(Unless, of course, your name is Ann and you don't want to risk the possibility of seeing any red. )

You've got it, Art!

Ann

The nose of the witch is the bluest protrusion pointing down in the middle of the picture. To the left of the nose is a "wavy line" which is the upper lip, the open mouth and the lower lip of the witch. (The witch has a large yellow "pimple", a bright yellow star, on her upper lip.) At lower left if the witch's chin. Her forehead and hat are presumably at upper right.

Ann