Thanks for the link.

"...while elliptical galaxies are almost devoid of them." Keyword: "almost". Just for kicks and giggles I will try to search HST for any. Perhaps some of these targets are within the grasp of amateur equipment.

That would be great!

I would be very interested in giving that a try myself, although it would have to be bright object.

To cut through the light pollution I have to contend with.

Cheers

Jo

It took a while, but it just dawned on my that in my collection of images there is one of M31 with M32 and M110 on the same image where I combined Halpha with LRGB. So, I have imaged at least 2 elliptical galaxies in Halpha and as Wouter was already surmising, there is very little structure (i.e. none to my eye) visible in the Halpha band.

Yes, I think Wouter is correct. I've worked my way through 20 Type-E galaxies at the Hubble Legacy Archive. No H-II regions but I did find something interesting: NGC 4589 and NGC 2768 have infrared filaments in orbit around the nucleus. From what I've read, supernovae are responsible. I examined the Hubble images in various wideband filters. I plan on imaging NGC 4589 with a standard blue filter which should give good contrast. I'll let you know how it goes!

Yeah, Andromeda is really full of them, but the other 2 galaxies in this field, not so much.

These two scientific papers may be interesting. I haven’t read them though so they may not be related to this discussion at all!

www.osti.gov/biblio/5198716-ionized-gas-...orbidden-ii-emission

adsabs.harvard.edu/abs/1986AJ.....91.1062P


Enjoy the read!

Wouter

Very, very interesting. Thanks, Wouter!