H beta

[JJDOBBER79]

Hi gang,
I just read that the rosette nebula has a large H 2 concentration. Are they referring to hydrogen beta? As in a hbeta filter will help on this target.? I am really just trying to justify buying one. Is the hbeta filter really just a one trick pony? Was that a pun?????.

[astro744]

Here's a list of some other H-Beta targets:

http://www.cloudynights.com/topic/h-beta-objects-listing?reply=374815349529377344

Same list also at http://jaysastronomyobservingblog.blogspot .com.au/2010/07/david-kniselys-useful-targets-for-h.html

See also http://www.lumicon.com/pdf/3filterspec_prnt.pdf

[JJDOBBER79]

Thanks again astro,
I think I will get one of these. mainly for the horsehead but I didnt want to get one just for that. Seems like there is quite a few targets that will benefit somewhat from one of these. I guess people are always looking for them for the horsehead anyway so I can resell when Im done with it.

[Merlin66]

Other that the variation caused by dust absorption the emission line at Hb is 50% of the Ha emission......
For visual I think they're selling the filter based on the sensitivity of the eye being greater at the yellow/ green compared with the red.
This is not strictly true either when you consider a dark adapted eye - rods and cones etc.

[Terry B]

The rosette will have Hb emission but that isn't what is meant by H2 or more correctly H II.
This is just astronomer speak for ionised Hydrogen meaning single H atoms that are also ionised rather than H2 which is the form of hydrogen we have commonly on earth.
The level of ionisation determines the emission frequency. As Ken stated, Hb is usually about 50% as strong as Ha.
see http://en.wikipedia.org/wiki/H_II_region

[JJDOBBER79]

thank you