A Warm Heart to get you through the Winter
Dear Lookout Observer,
Due to the frequent smoky California skies in the summer, ongoing concerns about the coronavirus, a lot of cloudy weather, and various family obligations, I have been unable to get to Lookout Observatory much this year. As a result I have had to resort to using the Observatory’s Southern Outpost (otherwise known as our backyard in Albany, CA) to get some pictures to send to you. The problem is that this Outpost is surrounded by major light pollution, which makes it impossible to see any but the brightest stars in the sky. Fortunately, modern science has developed a reasonably good solution – narrow-band filters. These filter out most light pollution and let only a few narrow wavelengths of light through, especially those wavelengths that are emitted by most galactic nebulae.
Image 1: If you live in a mid-northern latitude where there are dark, non-light-polluted skies, and you went out now on a clear night at about 9 PM, and you faced south and then looked up straight overhead, you would see a sky something like this image, except everything would be fainter (because this is a 25-minute time exposure, and your eyes can’t accumulate light over that much time). [This image was taken at Lookout Observatory.] Of course you wouldn’t see the green lines which I have added to make the constellations easier to find. But if you tilted your head back even further so you were looking a bit north of overhead, you could see the W-shaped constellation Cassiopeia (near the middle of this photo). Its 5 main stars that form the W are bright enough to be seen even in Albany with a lot of Bay Area light pollution. And just left of the W is a rectangular piece of sky marked with blue lines. This outlines the next picture.
Image 2: This approximately 5° x 7° piece of the sky contains two bright nebulae consisting mostly of glowing hydrogen gas, and each has one or more clusters of stars associated with it. Popularly known as the Heart and Soul Nebulae, each are regions of ongoing star formation. Previous generations of stars have exploded, spewing dust and gas into the region. Radiation and winds from current massive, hot stars cause the gasses to glow, and they create large cavities in the gas and dust, pushing outer regions together enough so that they begin condensing to form new generations of stars. The Soul Nebula on the left looks more like a fetus to me, but maybe that’s what souls look like? It is about 6, 500 light years away. The Heart Nebula is about 1000 light years beyond that. This picture is an hour and 40 minute exposure taken through a 200mm telephoto lens in our back yard.
Image 3: I rotated this close-up image so it looks more like a traditional heart shape. It is a seven-and-a- half-hour exposure taken through a telescope of 650mm focal length in our back yard. This heart of gas and dust is over 8 light years or about 50 trillion miles across. The hydrogen gas glows red when energized by the hot blue stars in the embedded cluster, and their blue light is scattered and reflected by the interspersed dust, the dark opaque parts of which have been carved into long columns and odd shapes by the intense radiation pressure from the existing stars.
I hope this heart brightens your long, dark winter nights, and I wish you Happy Holidays!
Keep looking up,
Carter, Resident Astronomer (rarely) of Lookout Observatory
Click on any image to get a closer look
