Object Of The Week November 22, 2020 – NGC 1499, The California Nebula

[wvreeven]

NGC 1499, Sh2-220, The California Nebula

Emission Nebula

Constellation: Perseus

RA: 04 03 18.0
DEC: +36 25 18

Mag: about 6.0

Size: about 2.5º long

I was looking through the OOTW objects and then DeepSkyForum in general and was surprised to barely find any references to this challenging nebula! The California Nebula was discovered by E.E. Bernard in 1884 (according to Wikipedia) or 1885 (according to Atlas Of The Universe). Unfortunately that is all I could discover about its discovery.

california-nebula-astrophotography.jpg
Source: https://astrobackyard.com/california-nebula/

It lies in the Milky Way's Orion Arm which the Sun is part of as well. The hydrogen in this cloud glows because of excitation by the nearby bright O7 star Xi Persei or Menkib. This is one of the exemplary nebulae for which UHC and especially OIII filters don't work. Instead a H-Beta filter is needed to observe this nebula visually. The nebula emits more light in H-Alpha but due to the poor response of human eyes to that wavelength, H-Beta filters work better. Due to its size and low surface brightness, very dark skies and large exit pupils are needed as well.

I am sure many of us have observed it at least once and I am curious to your observations. This APOD picture shows that the emission actually is much larger than generally seen in images and I wonder to what extend this is visible.

NGC1499_mosaic.jpg
Source: https://apod.nasa.gov/apod/ap190823.html

I have seen the nebula in telescopes as small as 60 mm and I suspect that it may be visible with small binoculars or possibly the naked eye as well. I have one observation logged with my good old 15 cm Newton telescope from the Netherlands. I used a 40 mm Plössl eye piece so the field of view was about 2º:

"At 25x I see a large glow when I move my telescope just north of Xi Persei. It is 2 to 3 fields of view in size and curves towards the south east. The south east end is surprisingly bright. The glow is split in two just north of Xi Persei. Some parts of the nebula are brighter than the rest. The glow is pretty faint, comparable to or slightly fainter than the Milky Way in Gemini."

Also don't forget to check out this galaxy behind the California Nebula:

http://www.deepskyforum.com/showthre...ifornia-Nebula


As always,

"Give it a go and let us know!
Good luck and great viewing!"