BA Sidewalk Astronomer

Observing the Caldwells

Caldwell 15, NGC 6826: "Blinking Planetary"

Locate the 4th magnitude stars Kappa, Iota and Theta Cygni. They are approximately 6 degrees north of Delta Cygni, the northwestern member of the crossbar of the Northern Cross.
Place Theta Cygni near the southern edge of a low-power eyepiece.
NGC 6828 lies 2 fields east.

Why the "Blinking Planetary?"
Through telescopes of 6-10 inch aperture, the small planetary is easily visible with averted vision. When directly viewing the central star, however, the nebula is invisible. So, when your eye moves first on then off the star, the planetary nebula appears to blink off and on. An intriguing effect.

Eyepiece Impressions:

• 8 inch SCT, f/10; 107x & 147x: "Some mottling w/averted; LPR no help, contrast improved w/UHC & OIII; still only mottled." AB
• 10 inch, LX200, 98x: "Planetary appears to wink in and out. I can discern a central ring with hole, and a bright spot in the center." DL
• 12 inch, 188x & 230x: "Very small at 188x. At 230x, central star visible. Appears almost perfectly round." PH
• 12.5 inch, 250x: "OIII did not really help, disappearance would happen after viewing directly. Bright, bluish spread out with somewhat fuzzy edges." CK

In early August:
Mercury sits low above the eastern horizon 40 minutes before sunrise. Venus shines brilliantly in the west shortly after sunset. Mars rises before 3 am. Jupiter hides behind the sun. Saturn climbs above the eastern horizon before 11 pm.

Patience pays off. 🪐🤩

After weeks of monsoon clouds, .christopher finally caught a break in the weather and captured this incredible view of Saturn. From the cloud bands to the crisp rings—and even a storm at 54° south latitude—there's plenty to take in.

🔭 Celestron C14

Several prominent stars highlight summer’s evening skies. Arcturus is high in the west at nightfall, with slightly fainter Vega overhead. The Big Dipper is in the northwest, and Antares, the heart of the scorpion, hunkers low in the south.