2024-02-26

South Plains Astronomy Club

Observing Under The Dark West Texas Skies

I’ve been photographing Comet Leonard since it emerged from the Sun’s brilliance into our evening skies. Since it is less than 10 degrees above the horizon, any cloud cover makes sighting the comet difficult, so the weather has only allowed four good nights of shooting.

As I write this on Dec 28, we have only a few more good days before the comet fades to obscurity. This week is probably the last chance to see or photograph Comet Leonard. Look low to the southwest (216 degrees on the compass) about 8 degrees above the horizon. You’ll need clear, dark skies to see it. A pair of binoculars will be your best bet now.

Comet Leonard position and predicted magnitude 12/28-01/22

Comet Leonard will curve back on itself in January and rapidly fade as it moves away from Earth:
12/28 – Mag 5.3 (naked eye visibility dark site*)
01/02 – Mag 5.8 (barely naked eye*)
01/07 – Mag 6.2 (not naked eye visible*)
01/12 – Mag 6.7
01/17 – Mag 7.3
01/22 – Mag 7.8

* As a general rule, magnitude 6.5 stars are considered the limit for the naked eye, but comets have this brightness spread out over a wider surface area and are therefore dimmer than a star of the same magnitude rating. To see stars and comets near the limit of your vision, you’ll need to let your eyes adapt to the dark (no white light) for at least 15 minutes.
– Magnitude is a logarithmic scale where the lower number is brighter by about 2.5. That means a mag 5.3 star is twice as bright as a mag 6.3 star.

My Photographs

My first photograph, on Dec 18 was in early twilight, but fortunately, the comet was nestled inside four magnitude 4 stars near bright Venus, making it very easy to find. It was as bright as these stars:

Comet Leonard by Tom Heisey on Dec 18, 2021, all rights reserved.
Comet Leonard barely visible on Dec 18 in bright twilight at Caprock Canyons State Park.

The next clear evening was Dec. 20. It had been a windy and dusty day, but fortunately had no clouds, so I had a chance to shoot it over an abandoned farm near Littlefield, Texas. As the comet rapidly moved away from sunset, it also got higher in the sky, making it much easier to see:

Comet Leonard by Tom Heisey on Dec 20, 2021, all rights reserved.
Dec 20, Littlefield, Texas

Fortune smiled on me again the next night and the overcast had an opening to the southwest. I finally got to an opening about 40 miles south of Lubbock near Lamesa, Texas. Since it was cotton harvest time, it was easy to find a nice foreground object:

Comet Leonard by Tom Heisey on Dec 21, 2021, all rights reserved.
Dec 21, Lamesa, Texas

The next opportunity to shoot the comet was Dec 23rd. Again, I had an opening to my southwest as a front pushed the clouds over Lubbock. I had to drive about 70 miles from Lubbock to get to an opening near Seagraves, Texas, not far from the New Mexico border. I picked a pivot irrigation system as my foreground and got a few shots:

Comet Leonard by Tom Heisey on Dec 23, 2021, all rights reserved.
Comet Leonard, Dec 23, Seagraves, TX

Unfortunately for me, just after that shot, the skies hit the dewpoint and the clouds covered the comet. Since it was still fairly high and I had clear skies under the comet, I drove southwest to try for a better shot. By the time I got 15 or 20 miles, Venus was setting into the dusty lower atmosphere, and I knew I had little time to try for the comet. I found it in my binoculars and heard a pump jack screech to life but couldn’t see it. I had just enough time to clamp my camera onto my window with my 180mm telephoto lens and snap a few shots as I aligned the long lens with the nearly invisible comet. It was worth the effort:

Comet Leonard by Tom Heisey on Dec 23, 2021, all rights reserved.
Comet Leonard, Dec 23, Seagraves, TX

I had stopped in a very lucky position! These two pumpjacks were the only ones I could hear in this pasture, and I had managed to stop for a perfect alignment with them! I had no time to reposition the car because the comet quickly hit the dusty lower atmosphere and faded to obscurity in just a few minutes. I didn’t even have time to adjust the camera for a shorter exposure to avoid star trails, but I am very glad I took the extra effort to get a longer shot of the comet!