Daniel Pasternak 10 Oct 2019 7d 6
The California Nebula (NGC 1499) is a vast cloud of glowing hydrogen about 2½° long and ¾° wide. It's known as the California Nebula because its shape, recorded on long-exposure photographs, is similar to that of the western state. Conventional wisdom has long held that the surface brightness of NGC 1499 is too low to be seen against the background sky visually in any telescope. Today the term low surface brightness (LSB) is used to describe large, diffuse objects such as the California Nebula. Their surface brightnesses are so close to that of the sky background that the observer can run his or her eye across the edge of the object without realizing the view has changed from sky to nebulosity. These objects are seen only when the sky is dark and transparent. A low magnification should be used so that the field of view shows plenty of sky to contrast with the object.
he California Nebula in Perseus is fainter but almost as large as the North American Nebula. The bright star below NGC 1499 is Xi Persei. North is up.
Daniel Pasternak 10 Oct 2019 7d 6
The California Nebula (NGC 1499) is a vast cloud of glowing hydrogen about 2½° long and ¾° wide. It's known as the California Nebula because its shape, recorded on long-exposure photographs, is similar to that of the western state. Conventional wisdom has long held that the surface brightness of NGC 1499 is too low to be seen against the background sky visually in any telescope. Today the term low surface brightness (LSB) is used to describe large, diffuse objects such as the California Nebula. Their surface brightnesses are so close to that of the sky background that the observer can run his or her eye across the edge of the object without realizing the view has changed from sky to nebulosity. These objects are seen only when the sky is dark and transparent. A low magnification should be used so that the field of view shows plenty of sky to contrast with the object.
he California Nebula in Perseus is fainter but almost as large as the North American Nebula. The bright star below NGC 1499 is Xi Persei. North is up.