A couple of days ago, I had my last glimpse of the last visible comet in the sky. Comet Lovejoy transited past the handle on the Big Dipper (which is actually part of a larger constellation, Ursa Major…the Great Bear), and continued on through Canes Venatici (Hunting Dogs) and Boötes (Herdsmen) into Corona Borealis (Northern Crown). It’s next stop is the constellation Hercules. The comet is quickly tracking towards the horizon, from its prior premium spot high in the sky, but not directly overhead such that it was difficult to observe. Our first major winter storm of the year finally rolled in yesterday, and the day before, when I captured the photos I’ve shared here, the first fingers of those clouds obscured my view by around 4:30am. The storm is set to linger for another day or two, with temperatures in the negative Fahrenheit at night and patchy clouds for another week (I don’t mind the cold, but -5° at 4am is getting into frostbitingly cold territory even for me!)
By the time temperatures return to levels where I could endure the cold mornings, Comet Lovejoy will be well into morning twilight range, and even more difficult to spot. I am not sure exactly what the future holds for this comet, long term projections so far have seemed hard to come by. It will not be making a very close approach to the sun, and as such, I do not expect it to become a clear naked-eye visible object (like it’s predecessor, Comet Lovejoy C/2011 W3, the previous comet discovered by Terry Lovejoy.) Until it’s return to the dark night sky, these are the last photos I’ll be able to make of this interesting little green “star.”
In addition to Comet Lovejoy, and all the others like ISON and Encke, lately it has been a pretty good time for planets. From the time the sun sets till it rises, we have no less than five planets that appear in the sky. Early in the evening a half-phase Venus presents brightly, high above the horizon. The heart of the night is currently dominated by Jupiter, which glows offwhite, almost cream colored, at a magnitude around -2.5 (very bright). Mars is visible in the very early morning sky, bright reddish-orange, about 45° above the eastern horizon. Just before dawn, as astronomical twilight begins to creep over the horizon, Saturn and Mercury are visible low to the east. When it comes to planetary observing, the more focal length you have, the better, 2500mm is usually decent, 5000mm is great.
I can currently get some fairly decent observing with the 600mm f/4 lens and a 1.4x TC attached (840mm). The planet is still quite small, however it’s atmospheric bands are visible. I have also been able to identify as many as five moons on the best nights, and the four major moons, the “Galilean Satellites”: Io, Europa, Ganymede & Callisto. In the photo I have shared here, the Galilean moons are visible…I am not sure where the fifth moon is, however it is usually barely larger than a single pixel and quite faint. It may be behind the planet as well.
I have mentioned before in previous blogs that winter is the domain of Orion, the Giant Hunter of greek mythology. Orion contains many of the most interesting objects and nebula in the sky. One of the most iconic nebula is the Orion Nebula, which is one of the few nebula visible with the naked eye, the second (of three) fuzzy “star” of Orion’s sword. I have yet to capture a long exposure of this nebula, or any of the other intriguing objects in the Orion constellation, however I still enjoy photographing it with the equipment I have. Again, my 840mm lens combination allows me to get fairly close, and gather quite a bit of light, as seen in the photo I am sharing today. This is my first decent “stack” of photos for Orion’s Nebula. I started using a different technique than I was previously, which nearly eliminates noise and produces much better results than I was getting in the past (which were often so poor that I never bothered to share them.) I’ll probably post a Knowledge Center article covering how to apply this stacking technique, for those interested.
Finally, I have a couple of interesting moon photos. I photograph the moon a lot, and have shared it in it’s many phases many times before on my blog. I decided to take a couple of my recent random photos of the moon to show off something a little different. The first is an intriguing consequence of trying to photograph the dark part of the moon. While it generally appears black to us when the moon is in a non-full phase, the dark part of the moon is actually illuminated by the Earth itself. This phenomena is called “earthshine”, and is not generally visible to the naked eye due to the fact that the brightness of the light reaching from reflecting off the earth is significantly dimmer than the sun. It is possible to see earthshine with the naked eye when the moon is in a very early or very late crescent phase, when it is barely more than a sliver.
In the photo above, an interesting flare phenomena occurred. In order to photograph the dark part of the moon, one has to greatly increase the exposure of the light part, not only overexposing it, but also making the camera susceptible to flare and ghosting. The flare (light separated and blurred by artifacts in the lens’ glass and a phenomena of the aperture) is the circular glow around the light part, and the ghosting (light reflected off the inside of the lens and/or an internal lens element back down to the imaging sensor) is the purple crescent-shaped thing hanging above the dark part. This wasn’t exactly what I was going for, but the end result was rather interesting…so I decided to share it.
Out of the attempt to photograph the dark part of the moon above, a new idea came to me. To try to produce something along the lines of an “HDR” photo of the moon. Capturing a true HDR photo of the moon is quite difficult. The exposures for the dark part tend to be long, and the moon transits across the frame quite quickly, making it impossible to do HDR in any normal fashion. Instead, I captured the moon with seven different exposures, which were carefully aligned and blended in Photoshop to produce the image you see below, where both the light and dark parts of the moon can be seen together: