A New Comet in the Sky

A recently discovered comet is now shining brightly in the morning sky. Comet C/2020 F3 (NEOWISE) was first spotted March 27, 2020, by NASA’s NEOWISE space-borne telescope. The comet passed inside Mercury’s orbit on 03 July 2020 and quickly brightened as it as heated by the intensity of the Sun.

Comet NEOWISE rises above Grand Canyon. Also visible are Venus, Hyades, and Pleiades.
Comet NEOWISE rises above Grand Canyon. Also visible are Venus, Hyades, and Pleiades.

The comet has been rising around the start of Astronomical Twilight when the eastern horizon is just beginning to brighten. Within about 45 minutes to an hour—or shortly after the start of Nautical Twilight—the morning sky has become bright enough to make observation difficult.

The image above was taken as the comet rose above Grand Canyon. Also visible in the image are the planet Venus, the bright star Aldebaran, and the Hyades and Pleiades star clusters.

Comet NEOWISE rises above the eastern horizon on 06 July 2020.
Comet NEOWISE rises above the eastern horizon on 06 July 2020.
Comet NEOWISE on 06 July 2020.
Comet NEOWISE on 06 July 2020.
Comet NEOWISE on 07 July 2020.
Comet NEOWISE on 07 July 2020.

By the third week middle of July the comet will shift from the morning sky into the evening twilight sky. Again, there will be a short window of time in which it is easily observed but viewing the evening is far easier than the morning.

 

A Thin Crescent Moon Reflected in the Lake

Although it’s fun to photograph the Full Moon, I actually prefer photographing a thin crescent Moon, usually just a day or two after the New Moon. The thin crescent is brightly lit while the remainder is softly lit by light reflected by Earth, hence known as Earthshine. It’s also known as DaVinci Glow. As well, the Moon does not overwhelm the night sky so that stars can also be in the photograph.

A wide-angle view showing the crescent Moon just above the horizon with Venus shining brightly above. The stars of Orion, Pleiades, and Hyades are also visible.
A wide-angle view showing the crescent Moon just above the horizon with Venus shining brightly above. The stars of Orion, Pleiades, and Hyades are also visible.

During late Spring and into early Summer the crescent Moon sets in the west-northwest and this makes it a good target for shooting at Upper Lake Mary. The long and narrow lake is aligned WNW–ESE so that the Moon casts a brilliant reflection that can run the length of the lake.

I’ve shot this several times over the last few years but never tire of it. All it requires is enough of a gap in the clouds for the Moon to shine and for light winds so that the lake surface is relatively smooth.

A zoomed-in view of the crescent Moon with reflection on Lake Mary.
A zoomed-in view of the crescent Moon with reflection on Lake Mary.
As the Moon settles closer to the horizon a thin veil of high clouds adds some interesting texture to the scene.
As the Moon settles closer to the horizon a thin veil of high clouds adds some interesting texture to the scene.

Venus and Pleiades Conjunction—April 2020

During the first few days of April 2020 the planet Venus moved towards and then through the Pleiades star cluster. Venus and Pleiades have a conjunction every year but every eight years the conjunction is at its closest. This year, Venus moved right through the star cluster.

Conjunction of Venus and Pleiades
Conjunction of Venus and Pleiades

I shot images of Venus and Pleiades on three nights: 01 April, 03 April, and 05 April. Venus and Pleiades were closest on the night of 03 April. I then did a composite image of the three nights showing the progression of Venus past the star cluster. These were all shot at 8 seconds, Ć’/4, 180mm, and ISO 800.

Additionally, I overlaid another image taken 13 February 2020. This is a stacked composite with 11 images shot at 120 seconds, Ć’/4, 180mm, and ISO 1600. The images were stacked using Starry Sky Stacker. The stack was then post-processed using rnc_color_stretch. This composite image was used because it shows the nebulosity and color within the Pleiades better than the shorter exposures captured that show the motion of Venus.

Composite image of Venus and Pleiades.
Composite image of Venus and Pleiades.

The image above shows the composite from the three nights without the additional layer showing the nebulosity.

A New-to-Me lens for Astrophotography

I recently acquired a used lens that I plan to use for astrophotography. The Nikkor 180mm f/2.8 ED AI-S is well-known as an excellent lens for this purpose—assuming, of course, you get a good copy of the lens.

Pleiades (M45).
Pleiades (M45).

Jerry Lodriguss, over at AstroPix, has this to say about the lens:

The Nikon 180mm f/2.8 ED lens is a legendary lens, and with good reason. It’s performance for normal daytime photography is simply outstanding. And it is pretty darn good for astrophotography also…

I have been looking at used copies of this lens on-and-off for several years but have never actually been excited enough to purchase one. That is, until I saw one listed in MINT condition for an extraordinary price. The lens was offered by Tempe Camera and the store was close enough that I could drive down there in a few hours. Off I went…

And the lens really was in Mint condition. After a bit of checking and a few test shots I bought it. Now it was time for testing. On my first night my results weren’t that great but I attribute that to the fact that it was COLD and my fingers weren’t very good at getting sharp focus and it was windy causing the camera to shake resulting in blurry images.

So, I headed back out again the next night. I sought a location without wind and at a lower elevation hoping for warmer temperatures. Well, it wasn’t warmer but there was no wind.  And the results were pretty good. Comparing the results at various f/stops (f/2.8, f/4.0, and f/5.6) I could see how the image improved with smaller apertures. And a comparison with my very old Nikkor 80-200mm AI-S f/4 showed that the 180mm was better than the zoom lens at equivalent apertures.

I’m pretty happy with the quality of the lens and the price I paid. Now all I need is some clear skies to get out and do some more shooting.

 

Meteors and Comets

The past few nights have been interesting. On the evening of December 13–14 was the peak of the Geminid meteor shower. This year the expected peak was around 100–120 meteors per hour and various meteor counts appear to confirm that number.

At the same time, Comet 46P/Wirtanen has been getting a lot of attention. On December 16 it made its closest approach to Earth—only 11.5 million km away. That’s about 30 lunar distances for reference.

From SpaceWeather.com: “Although the comet is very close to Earth, it is not very bright. 46P/Wirtanen is a relatively small comet and, thus, barely visible to the unaided eye despite its proximity. It is nevertheless an easy target for digital cameras. Even a short exposure reveals the comet’s spherical form and emerald green hue.”

During the late evening of December 13, I traveled to Wupatki National Monument because of its dark skies. I shot a sequence of photos—each of 30 seconds duration—of the night sky hoping to catch a few meteors. One bright meteor blazed across the sky and I was able to catch part of it before it moved out of the frame of the camera. At the same time, the crescent Moon was setting in the west and gently illuminating Wukoki Pueblo. At the very top center of the photograph is Comet 46P/Wirtanen.

Geminid meteor, Comet 46P/Wirtanen and Wukoki Pueblo.
Geminid meteor, Comet 46P/Wirtanen and Wukoki Pueblo.

After about 1/2 hour of shooting meteors, I shot longer exposures of the comet. On this night, the comet formed a triangle with the Pleiades and Hyades star clusters. The image shown here is from ten 60-second images stacked using Deep Sky Stacker (DSS) and post-processed using  rnc-color-stretch.

Comet 46P/Wirtanen with the Pleiades and Hyades star clusters.
Comet 46P/Wirtanen with the Pleiades and Hyades star clusters.

A few nights later, the comet had moved so that it was between the Pleiades and Hyades clusters. Again, I shot a sequence of 60-second exposures totaling about one hour in duration—this time from the Mormon Lake overlook. The motion of the comet is quite apparent in this sequence of images. The first image shows the motion of the comet against the stars; the second is a time-lapse movie of the same sequence.

The motion of Comet 46P/Wirtanen is seen as a short streak in this one-hour composite image.
The motion of Comet 46P/Wirtanen is seen as a short streak in this one-hour composite image.

Time lapse movie showing the motion of Comet 46P/Wirtanen during a period of one hour.

Comet 46P/Wirtanen is now moving farther from Earth and will slowly dim in brightness but it will remain visible through binoculors, telescopes, and with digital cameras for many weeks or more. There is still plenty of time to see the comet if you haven’t already.