Comets

Dear Friends of Lookout Observatory,

My wife Anitra and I were at Lookout Observatory this morning (July 11), and we got up at 3:30AM to see Comet Neowise (Otherwise known as C/2020 F3). We set up chairs in the meadow and had cameras ready. From the time the comet rose in the Northeast above the distant trees just as early dawn was starting to the time when the brightening sky made the comet disappear seemed amazingly short. Anitra saw the comet first just peeking above the trees, and about half an hour later, after fussing with the camera to get it in focus with the right exposure, I got our best picture, attached below. As the comet faded in the brightening dawn, we heard a rooster crow, then a pack of coyotes squealing and howling for a couple of minutes over by the reservoir, then a surround sound of barking neighborhood dogs, and then silence except for the wakening birds. It was a lovely country morning, and we wanted to share with you an image of the brightest comet to come around in years.

Technical Data: Canon EOS Rebel XS camera, 200mm f/2.8 lens wide open, ISO1600, 1 sec. Exposure, July 11, 2020, 4:28 am PDT, Lookout, CA. Image cropped to about 85% of original.

Keep looking up,

Carter Mehl, (sometime) Resident Astronomer,

Lookout Observatory

Dear Friends,

There is a comet in the evening sky right now visible with the naked eye (barely) from a dark-sky location and visible with binoculars even in light-polluted urban areas. This is the 5^th comet discovered by Australian amateur astronomer Lovejoy in just a few years. It is designated C 2014 Q2 (Lovejoy). If you want to see it, you need to know where to look, so I have attached a chart showing its location throughout January. It just looks like a fuzzy star to the eye, but long exposure photos show its tail. If you don’t want to bother looking in the sky, but want to see how it anyway, I have attached a photo taken from Lookout Observatory about 9 PM PST on January 13. The long dimension covers about 8 degrees, and you can trace the tail over at least 6 degrees. (For comparison, the full moon is about ½ degree across.) This photo was taken over 35 minutes of time, and I tracked on the comet, so you can see how much the stars trailed in that time. This gives you an idea of how rapidly the comet moves relative to the background stars. The 3^rd and final attachment is a closer up photo taken through a 200mm lens rather than the 100mm lens used for the first photo. Even though it is twice the scale of the first photo, there is less movement relative to the stars because it was only 9 minutes long. However, it shows some of the detail (streaks) in the tail better. I hope you enjoy these pictures, and remember to keep looking up!

Carter Mehl,
(Sometime) Resident Astronomer,
Lookout Observatory

Greetings Lookout Observers,

There is currently a comet in your night sky that, though too faint to be seen with the naked eye, is visible as a little blob of light with a good pair of binoculars held steady. It is Comet Jacques (2014E2), named, as all comets are, after its discoverer. Because it is in the constellation of Cepheus, headed toward the constellation Cygnus, it is well placed for Northern Hemisphere observers, being somewhat North of straight overhead just after dark. In another week or two it will probably start fading from view. Last week at Lookout Observatory I observed the comet in binoculars and then photographed it with the 11-inch diameter telescope for a close up view. Comet’s tails are what usually makes them interesting, but I couldn’t see any tail in the binoculars, probably because the comet had already moved too far from the sun. The Manx is a kind of cat that doesn’t have a tail, so I thought it might be appropriate to call this comet a “Manx” comet. The first picture attached is a photo of Comet Jacques, but all that can be seen is it’s greenish head even though this is a 30 minute exposure (60 thirty second exposures stacked). The nearby stars are all streaked because I tracked on the comet, and it moved that much in 30 minutes. (To give you a sense of scale, the full moon would fill up this whole photo.) If there is any tail at all, it is very short and extends to the lower right of the head

Because a tailless comet is not so interesting, I am also including a second photo which I took the same night as the comet picture. It is of NGC 6781, a small planetary nebula in the constellation Aquila. Planetary nebulae get their name because when they were first being discovered, they looked like a planet looks in a small telescope. In reality they are many light years away, scattered across our Milky Way Galaxy. They result when many stars, as part of their evolution, blow off a massive shell of gas which then expands, usually in a sphere. It usually looks like a ring because the gas is dense at the sides where you are looking through lots of it, and thinner in the middle where you are looking straight through the spherical shell, and therefore there is less gas. This nebula is about 2 light years across (about 30,000 times the diameter of the Earth’s orbit around the sun), but because it is so far away (a couple of thousand light years), it looks very small in a telescope. This photo covers the same amount of sky that the comet photo does, so you can see it appears smaller than the comet. Please enlarge it to an inch or two across so you can see the full color beauty of it. When the image is blown up, you can see the small blue star in the very center that originally blew off the nebula. All the other stars are foreground or background stars. The blue in the nebula is caused by reflection of light from the blue central star, whereas the red in the nebula is caused by the emission of light from hydrogen gas that is energized by the radiation from the central star.

I hope you enjoy these celestial wonders and have had an enjoyable summer. And remember …

Keep looking up,

Carter,

Sometime Resident Amateur Astronomer,

Lookout Observatory