Comet C/2014 Q2 Lovejoy is still visible in the sky in the constellation Cassiopeia. It is not as bright as it was a few months ago but can still be seen with a pair of binoculars. It is probably best viewed in the evening as Cassiopeia moves lower in the sky overnight and in the early morning hours. This makes it more difficult to see as there is more atmospheric attenuation at these lower elevation angles.
Using my recently acquired iOptron Skytracker for tracking night sky objects I took numerous exposures totaling 14 minutes (9x60s@iso1600; 10x30s@iso3200). These were then stacked in Deep Sky Stacker (DSS), a very good and free program designed for astrophotography.
Here are a few recent images of the nearly-full moon rising above the San Francisco Peaks in northern Arizona. The day before the full moon is often the most photogenic time as the landscape is still bathed in sunset light while the moon has already climbed well above the horizon.
But if only it was that easy! Earlier in the day I had used The Photographers Ephemeris (TPE) to find a location. I decided that a position on SR64 north of Williams, Arizona, would work and at that distance the moon would appear quite large juxtaposed against the mountains. Unfortunately, when I arrived at my predetermined spot I was not able to see the mountains. Numerous cinder cones and small hills completely blocked my view. I wish TPE was more intelligent than this photographer and would let me know of obstructions.
With less than 15 minutes until moonrise and one-half hour until the moon would be above the peaks, I had to find a new location quickly. I backtracked south on SR64 and then east along Route 66 but hills and trees continued to block my view. When I did finally get a clear view I was too far south and the moon would rise south (right) of the peaks. I stayed around for a few minutes to get a few consolation images of the moonrise then headed east again. Arriving in Parks, Arizona, I turned north and kept looking for a location with the moon above the peaks and a clear view. Finally, I found this location.
Although these were not the images I thought I was going to get I’m still happy with the result.
Note: No speed limits were broken while trying to reposition!
As mentioned in a previous post, I now have a tracker mounted on my tripod (iOptron SkyTracker). With this gadget, I can take longer exposures of the night sky without star trails. Exposures of 30 to 120 seconds typically give me the best results. Shorter exposures don’t gather enough light and the longer exposures may show a hint of star trails.
There was an evening a bit over a week ago with mostly clear skies. Very thin cirrus clouds were moving across the area. I was unable to see them while photographing but inspection of satellite imagery at the time showed that there was some high-altitude moisture moving across the area. The result? The thin clouds produced a faint glow around the brighter stars in the constellation Orion. I like the result.
Comet C/2014 Q2 Lovejoy continues to be a fascinating object to photograph in the evening sky. It is now located high in the sky at sunset and sets in the northwest overnight. It is, however, growing fainter and this requires longer exposure times to bring out the details. As noted in a previous post, I have been photographing the comet without the aid of an equatorial mount and this has limited my exposures to a few seconds. That has changed as I now have a tracker mounted on my tripod (iOptron SkyTracker) and this allows much longer exposures. It takes a bit of practice to properly align the device but I’ve gotten pretty good with a few sessions. With good alignment, it is possible to take exposures of 5–10 minutes without getting star trails.
On another night, I was again taking a sequence of images when some high, thin clouds moved in. Rather than shutting down, I continued to capture images. The result of the high clouds was to create a colored area around the brighter stars.
Cloudy skies have returned to northern Arizona and that will be the end of comet photography for at least a few days.
Comet Lovejoy (known formally as C/2014 Q2) continues to put on an impressive show for sky watchers. In December it began to climb upwards from the southern horizon towards Orion, then passing to its west and climbing higher. In mid-January it was nearly overhead in the evening sky as it passed near Taurus and Pleiades. Many astrophotographers have taken advantage of this setting and there have been some beautiful photographs posted at various web sites.
To best capture the delicate details of the comet—and especially its tail—a tracking device is needed to guide your camera or telescope so that it matches the motion of the stars across the sky. This allows longer exposures without the stars streaking or creating star trails. Without a tracking device, exposure time is limited. This limitation can be partially overcome by taking numerous short exposure images and stacking them using any of the many applications available. Still, the laws of physics and the engineering of camera sensors will result in better images if you have, say, five 30-second exposures than thirty 5-second exposures—even though both are 150 seconds total exposure.
Are 100 x 1 minute and 10×10 minutes giving the same result? Yes when considering the SNR but definitely No when considering the final result. The difference between a 10-minutes exposure and a 1-minute exposure is that the SNR in the 10-minutes exposure is 3.16 higher than in 1-minute exposure.
Thus you will get the same SNR if you combine 10 light frames of 10 minutes or 100 light frames of 1 minute. However you will probably not have the same signal (the interesting part). Simply put you will only get a signal if your exposure is long enough to catch some photons on most of the light frames so that the signal is not considered as noise.
For example for a very faint nebula you might get a few photons every 10 minutes. If you are using 10 minutes exposures, you will have captured photons on each of your light frames and when combined the signal will be strong. If you are using 1 minute exposures you will capture photons only for some of your light frames and when combined the photons will be considered as noise since they are not in most of the light frames.
Since I don’t have a tracker (at least, not yet), I have no choice but to stack short-exposure images of the comet. Here are a few images of Comet C/2014 Q2 Lovejoy taken on several different nights. The quality of the images varies depending on how much light pollution was captured in the image, whether there was moonlight, and how clear the sky was.
There’s still plenty of time this winter to venture outside with a pair of binoculars and gaze at the comet. Here is a link to a sky chart provided by Sky and Telescope for the month of January. For February and beyond, try this chart hosted by UniverseToday.
A few days ago I headed down to Sedona to try getting another set of images of Comet C/2014 Q2 Lovejoy. Although I did get the images, I was unable to create a final product that showed the stars and the comet well. I suspect there was too much light pollution and it overwhelmed the delicate tail.
I also shot star trails with the camera pointed toward Cathedral Rock. The moon was still below the horizon when I started the sequence of images but rose above the horizon and illuminated the rock at the end. The result, after stacking and compositing the images was pretty good. But I was interested in trying out a popular technique of making the star trails look more like, well, comets. There is software available to do this but I was willing to do it the old-fashioned way using manual labor—at least this one time. The result came out well. If only the night sky actually looked like this!
It’s been an interesting fall around here with regards to precipitation. The December statistics for Flagstaff are interesting. Up through 12/29/2014, there had been 2.75″ of water equivalent (both rain and melted snow). Normal for this period is 1.60″. Snowfall, on the other hand, has been mighty scarce. There had been a total of 4.9 inches this fall/winter; normal should be closer to 26 inches. What a difference!
But all that changed dramatically with the arrival of a strong and cold winter storm on New Year’s Eve day and continuing into the New Year’s Day. Snow levels fell to very low elevations with this storm and photographers were flocking to their favorite locations to capture amazing images of the desert with snow. Even Phantom Ranch, at the bottom of the Grand Canyon, received some snow from this storm.
An interesting aspect of this event was the cold front that pushed southward across the Great Basin and brought frigid air to southern Utah and northern Arizona just before the storm arrived. Then, when the precipitation began it fell into very cold air—and did not melt—resulting in snow accumulations around the very low elevations of Lake Powell and Page. This location is well known for being highly photogenic and the addition of snow makes it even better.
Closer to home, significant snow fell in Flagstaff (16-20 inches), Oak Creek Canyon, and Sedona. In fact, folks suggest this may have been the most snow from a single storm in several decades with 8-10 inches decorating the famous Red Rock Country.
And it was an amazing sight when the sun finally broke through the clouds.
Comet C/2014 Q2 Lovejoy has been climbing northward and is now well above the horizon for easy viewing in the northern Hemisphere. Sky and Telescope magazine has a good article showing where the comet is located each night in the sky through January.
With inclement weather approaching and threatening to eliminate any chances of photographing comet C/2014 Q2 Lovejoy for the next week (or more), I took advantage of one last clear, chilly night. The comet was easily visible in 7×50 binoculars and faintly visible as a naked-eye object.
The first image shows the well-known Cathedral Rock in Sedona, Arizona, with the comet visible in the lower left. Shot with a wide-angle lens, the tail is barely distinguishable in this image. In the upper center of the image stands Orion.
(ISO 1600, 28mm, f/2.8, 15 seconds.)
The second image clearly shows the tail extending up and to the left. (ISO 1600, 85mm, f/1.8, 8 seconds.)
The third image is a composite of 100 images each of 8 seconds duration and stacked with Deep Sky Stacker and shows a much longer and more detailed tail. (ISO 1600, 85mm, f/1.8 100×8 seconds.)
All images were taken using a fixed tripod with no tracking. I would like to try a equatorial tracking device so that I might be able to take longer exposures without the stars developing trails. Perhaps that will be my next photo equipment purchase.
Widespread, dense fog covered portions of northern Arizona for more than a week in early December. The fog appeared at Winslow, Arizona (KINW), during the evening of December 3 and finally dissipated on the afternoon of December 12. Similar conditions were experienced in Flagstaff, Arizona (KFLG), with fog appearing on the afternoon of December 4 and finally dissipating in the evening of December 10. For some locations, including Flagstaff, the fog was episodic with periods of dense fog interspersed with clear conditions. Farther to the northeast, including places such as Winslow and the Chinle Valley, the fog was more persistent.
The fog was the result of a heavy rainfall event across northern Arizona December 2–4. Many locations received between 1 and 2 inches of rain. Following the rain, high pressure developed across the southwest and a strong thermal inversion developed. The inversion was finally removed when a trough moved across the region bringing strong southwest winds and steeper lapse rates.
It should be noted that thermal inversions are not rare. Quite the contrary. An inversion commonly occurs at night and during the winter when the angle of the sun is very low in the sky. After last years fog event in the Grand Canyon, some in the media declared that thermal inversions are rare and that the inversion was the cause of the fog. Not really. Both then and now the moisture evaporated out of the soils but was trapped near the ground by the inversion. And, slowly but surely, the moisture content of the lowest few hundred meters of the atmosphere became saturated and fog developed.
Well—enough of the meteorological explanation. What did it look like?
When these shallow fog events occur it is possible to find hills and mountains that are above the inversion so that an observer can look down on the fog. This often results in some amazing photographic opportunities. Anticipating that the fog would occur, I was ready to travel to the Grand Canyon to capture images of the fog filling the canyon. Well, it didn’t quite fill the canyon—at least, not like last year. But there were still photographic opportunities.
I also found myself on the lower slopes of the San Francisco Peaks north of Flagstaff and was able to capture images and video of the fog streaming across the pass between the San Francisco Peaks and O’Leary Peak as well as the sea of fog across the Little Colorado River Valley.
It’s been a dry autumn in northern Arizona but a recent storm brought moderate rainfall amounts to much of the area. This was greatly appreciated as the trails were becoming dry and dusty and wildfires were beginning to pop again.
But even more important—from the perspective of a photographer—was the possibility of fog across northern Arizona, especially in and near the Grand Canyon. Last year, a major rain event resulted in a moist boundary layer that persisted for many days and led to widespread fog and a very photogenic fog event in the Grand Canyon.
The possibility existed that this could happen again so early Friday morning I arose before dawn and checked the weather conditions. Everything looked good so I drove up to the South Rim of the Grand Canyon. The best fog was located in the Little Colorado River valley and to the east of the Grand Canyon. The fog was slowly pushing westward and then spilling over the edge of the canyon and evaporating as it descended.
Slowly the canyon began to develop fog within the depths that would at times race upwards to the rim. When these patches of fog were located directly opposite the direction of the sun, a Glory and Brocken Spectre would appear. I was shooting images with a 10 second interval and assembled these into a short video showing the fog spilling over the edge as well as the appearance and disappearance of the glory several times.
Low-level moisture remains plentiful across the region and with the development of a large area of high pressure aloft and a thermal inversion the chances of fog in the Grand Canyon will continue for the next few days.