English: Astrophotograph of the California Nebula (NGC 1499/Sh2-220) in the Constellation Perseus. The nebula is a cloud of hydrogen gas and dust approximately 100 light-years wide and situated about 1,200 light-years from Earth. In its denser regions, young stars are actively forming. The nebula is excited by the nearby O-type giant star Xi Persei (also known as Menkib), which appears above the nebula in the image. Xi Persei is roughly 30 times more massive than the Sun, five times hotter, and nearly 300,000 times more luminous—making it one of the hottest stars visible to the naked eye.

The California Nebula has a relatively low surface brightness, meaning it is extremely difficult to observe with the naked eye even under minimal light pollution. It was first discovered in 1884 by renowned American astronomer E. E. Barnard, who observed it using a 6-inch refractor telescope under exceptionally dark skies.

The nebula earned its nickname due to its resemblance to the shape of the state of California in long-exposure photographs. Interestingly, for observers located in central California, the nebula passes directly overhead at zenith during its daily transit.

This photograph was taken in early September 2024 from the town of Tõrva, Estonia.

Equipment Used:

• Telescope: Sharpstar 61EDPH III
• Mount: EQ6R-PRO
• Camera: ASI071MC Pro
• Accessories: Sharpstar 61EDPH focal reducer
• Filter: Optolong L-eNhance 2"

Exposure Time: 149 × 320 seconds (+50 flat frames, 50 dark flats, 50 darks)

Software: PHD2, N.I.N.A, PixInsight, Photoshop