Campbell’s Hydrogen Star (PK 64+5.1, PN G 64.7+05.0, Hen 2-438, BD +30 3639)

„Red“ Planetary Nebula

Cygnus

Size: 6“
Mag: 11,3 (CS)

RA 19 34 45
DEC +30 30 59

Cambell’s Hydrogen Star is a very unusual WR star, which has very strong hydrogen lines and missing green oxygen lines.

The star itself was cataloged through the visual Bonner Durchmusterung (that’s why BN) as the usual star BD +30 3638. Williamina Fleming discovered the unusual spectrum of this star 1890. Three years later William Campbell reported again about the bright H-alpha emission lines. He also detected a nebulous character with his Spectrometer.


The visual interesting detail is the 5” nebula around the central star and the color.

The halo itself can be seen with telescopes from the 12”-14” range. Under good to very good seeing the halo could be resolved as a very small ring with better defined and brighter SE and NW ring parts. Hß filters help to resolve the halo from bright and disturbing CS (10,3mag). UHC and [OIII] doesn’t help.
Also very interesting and exciting is the color of the PN. It is one of the few Deep-Sky-Objects from what we can observe visually its red characteristic. Most people with mid range telescopes reported a red or orange CS. But the color itself is formed from the halo. My own experience with 27” showed a white CS and a red to orange halo/ring. There are other reports and observations which confirm this.

What do you see?

"GIVE IT A GO AND LET US KNOW"

GOOD LUCK AND GREAT VIEWING!

sketch, 16", 697x, Seeing II, fst 6m5+ (home)
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Subaru Telescope, National Astronomical Observatory of Japan (NAOJ)
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