![](http://astro.hal1.se/wp-content/uploads/2023/03/IC_405_63min_LPfilter_PS_small-1024x684.jpg)
An emission nebula is a nebula formed of ionized gases that emit light of various wavelengths. The most common source of ionization is high-energy ultraviolet photons emitted from a nearby hot star. Among the several different types of emission nebulae are H II regions, in which star formation is taking place and young, massive stars are the source of the ionizing photons; and planetary nebulae, in which a dying star has thrown off its outer layers, with the exposed hot core then ionizing them.
Click on the pictures below for more information and additional photos.
![IC 59 and IC 63 Gamma Cassiopeia Nebula](https://astro.hal1.se/wp-content/uploads/2023/06/ic_59_120min_filter_xtrm_ps-1024x679.jpg)
![IC 405, Flaming star nebula](https://astro.hal1.se/wp-content/uploads/2023/03/ic405_54min_lrgb-1024x819.jpg)
![Sadr (Gamma Cygni) and IC 1318](https://astro.hal1.se/wp-content/uploads/2023/04/gamma_cygni_90min_filter_nd1_ps-1024x437.jpg)
![IC 1396 Elephant trunk](https://astro.hal1.se/wp-content/uploads/2023/08/ic1396_75min_lhargb_ps-1024x819.jpg)
![IC1805, Heart nebula](https://astro.hal1.se/wp-content/uploads/2023/04/ic_1805_162min_lpfilter_ps-1024x684.jpg)
![IC 1848, Soul nebula](https://astro.hal1.se/wp-content/uploads/2023/04/ic_1848_144min_lpfilter_ps-684x1024.jpg)
![IC 2177, Seagull Nebula](https://astro.hal1.se/wp-content/uploads/2023/06/ic_2177_78min_nbfilter_ps-1024x684.jpg)
![IC 5070 Pelican Nebula](https://astro.hal1.se/wp-content/uploads/2023/08/ic_5070_80min_nbfilter_2_ps-684x1024.jpg)
![IC 5146, Cocoon Nebula](https://astro.hal1.se/wp-content/uploads/2023/10/ic5146_97min_lhargb-1024x754.jpg)
![M42, Orion Nebula](https://astro.hal1.se/wp-content/uploads/2023/03/m42_34min_ps-665x1024.jpg)
![NGC 281 Pacman nebula](https://astro.hal1.se/wp-content/uploads/2023/06/ngc_281_48min_filter_ps-1024x698.jpg)
![NGC 896](https://astro.hal1.se/wp-content/uploads/2023/08/ngc_896_hasiioii_80min_ps-1024x811.jpg)
![NGC 1499 California Nebula](https://astro.hal1.se/wp-content/uploads/2023/08/ngc_1499_150min_filter_nb1_ps-1024x684.jpg)
![NGC 2174, NGC 2175 and IC 2159](http://astro.hal1.se/wp-content/uploads/2023/08/ngc_2175_54min_lpfilter_ps-1024x684.jpg)
![NGC 2237 Rosette nebula](https://astro.hal1.se/wp-content/uploads/2023/04/ngc_2244_60min_ps-1024x684.jpg)
![NGC 2359, Thor's Helmet](https://astro.hal1.se/wp-content/uploads/2023/06/ngc2359_66min_hared_54min_oiiiblue_ps-1024x811.jpg)
![NGC 6888, Crescent nebula](https://astro.hal1.se/wp-content/uploads/2023/04/ngc_6888_120mi_filter_xtrm_ps-1024x684.jpg)
![NGC 7000, North America Nebula](https://astro.hal1.se/wp-content/uploads/2023/03/ngc_7000_75min_filter_nb1_ps-1024x682.jpg)
![NGC 7635, Bubble Nebula](https://astro.hal1.se/wp-content/uploads/2023/06/ic_7635_80min_hargb_ps-1024x821.jpg)
![NGC 7822](https://astro.hal1.se/wp-content/uploads/2023/10/ngc_7822_140min_nb1_ps-756x1024.jpg)
![Sh2-155, Cave Nebula](https://astro.hal1.se/wp-content/uploads/2023/10/sh2-155_249min_nb1_ps_cropped-1024x667.jpg)
![Lower's Menula, LBN 863, Sh 2-261](https://astro.hal1.se/wp-content/uploads/2024/02/lbn863_183min_ps-1024x684.jpg)