The California Nebula is an emission nebula in the constellation Perseus (NGC 1499/Sh2-220) that was first discovered by E. E. in 1884. Its name refers to how it appears in long exposure photos like the outline of the US State of California. It spans about 2.5° of the sky, however, due to its exceedingly dim surface brightness, it is quite challenging to view visually. A rich-field telescope with a dark sky can be viewed using a Hα filter (which isolates the Hα line at 486 nm or 656 nm). It is around 1,000 light years away from Earth. Its fluorescence is caused by the nearby extraordinarily active O7 star Xi Persei, which excites the nebula's Hβ line.
This nebula spans around 100 light-years across and resides in the constellation of Perseus, on the Orion arm of our galaxy along with multiple other objects which reside close to us (M42, M45 and several open clusters)
This nebula spans around 100 light-years across and resides in the constellation of Perseus, on the Orion arm of our galaxy along with multiple other objects which reside close to us (M42, M45 and several open clusters)
This target is fairly large, not the biggest but using my equipment it would need a 2/3-panel mosaic to fit the whole nebula in (another night project). This target was taken with a One Shot Colour style camera which takes RGB colours in one shot. a Nebula filter was used to narrow the colours down to Hydrogen and Oxygen (Hα and OIII) to bring out the more prominent colours of the nebula
California Nebula is fairly close to Orion, residing above Pleiades in the night sky. This make this target hard to photograph at certain times of the month due to the Moon also following the same path (depending where you live) as well as it being a seasonal target with it being extremely low, or under the horizon from April to October, with the best times to photograph this target being in December.
The equipment used to take this was the following:
- Scope – Celestron RASA 8
- Mount - Skywatcher EQ6 R Pro
- Guide scope – ZWO 30mm
- Guide Camera – ZWO ASI 120mm mini
- Main Camera – ZWO Asi 533mc Pro
- Control box – ZWO ASIAIR Pro
- Filter – IDAS NBZ Nebula Booster 2”
- Starizona Filter drawer next to the camera sensor
- Fox Halo 96k power bank
- Dew heater with its own power bank on the guide scope
- Main scope Celestron ring dew heater powered though the ASIAir
Above is a reprocessed version of old data collected in 2022. This has used new processing software which are plugins for Pixinsight. The overall results are much better and more controlled stars.
While the stars were removed to process the nebula, I used photometric Colour calibration to help get the correct colours for the stars. Overall these stars appear more natural and better looking than the original. The stars were collected with the nebula. If you have time, it is recommended to collect UV/IR stars (30-60 secs F4+ for 30-45mins, F2 - 5 secs for 20 mins and use these stars in place of the Narrowband stars.
While the stars were removed to process the nebula, I used photometric Colour calibration to help get the correct colours for the stars. Overall these stars appear more natural and better looking than the original. The stars were collected with the nebula. If you have time, it is recommended to collect UV/IR stars (30-60 secs F4+ for 30-45mins, F2 - 5 secs for 20 mins and use these stars in place of the Narrowband stars.
Processing this target was fairly easy and I'm sure multiple versions of this will eventually be made, including a Mosaic style picture covering the whole nebula which will most likely take 2-3 panels