dark skies – The Amazing Sky

May 17, 2015May 17, 2015

Scenes at the Texas Star Party

The stars at night shine big and bright, deep in the heart of Texas.

Last week several hundred stargazers gathered under the dark skies of West Texas to revel in the wonders of the night sky. I was able to attend the annual Texas Star Party, a legendary event and a mecca for amateur astronomers held at the Prude Ranch near Fort Davis, Texas.

Some nights were plagued by clouds and thunderstorms. but here are some scenes from a clear night, with several hundred avid observers under the stars and Milky Way. Many stargazers used giant Dobsonian reflector telescopes to explore the faintest of deep-sky objects in and beyond the Milky Way.

A 360° panorama of the upper field of the Texas Star Party at the Prde Ranch near Fort Davis, TX, May 13, 2015, taken once the sky got astronomically dark. The panorama shows the field of telescopes and observers enjoying a night of deep-sky viewing and imaging. Venus is the bright object at right of centre and Jupiter is above it. The Zodiacal Light stretches up from the horizon and continues left across the sky in the Zodiacal Band to brighten in the east (left of centre) as the Gegeneschein. I shot this with a 14mm lens, oriented vertically, with each segment 60 seconds at f/2.8 and with the Canon 5D MkII at ISO 3200. The panorama is made of 8 segements at 45° spacings. The segments were stitched with PTGui software. — A 360° panorama of the upper field of the Texas Star Party at the Prde Ranch near Fort Davis, TX, May 13, 2015, taken once the sky got astronomically dark. The panorama shows the field of telescopes and observers enjoying a night of deep-sky viewing and imaging. Venus is the bright object at right of centre and Jupiter is above it. The Zodiacal Light stretches up from the horizon and continues left across the sky in the Zodiacal Band to brighten in the east (left of centre) as the Gegeneschein.
I shot this with a 14mm lens, oriented vertically, with each segment 60 seconds at f/2.8 and with the Canon 5D MkII at ISO 3200. The panorama is made of 8 segements at 45° spacings. The segments were stitched with PTGui software.

Observers at the Texas Star Party explore the wonders of the deep sky under the rising Milky Way, in May 2015. Sagittarius and Scorpius are in the background, with the centre of the Galaxy rising in the southeast. This is a single 30-second exposure at f/2 with the 24mm lens and Canon 5D MkII at ISO 4000.

Expert deep-sky observers Larry Mitchell and Barbara Wilson gaze skyward with Larry’s giant 36-inch Dobsonian telescope at the Texas Star Party, May 2015. This is a single 60-second exposure with the 14mm lens at f/2.8 and Canon 5D MkII at ISO 3200.

A deep-sky observer at the top of a tall ladder looking through a tall and large Dobsonian telescope, at the Texas Star Party, May 2015. Scorpius is rising in the background; Saturn is in the head of Scorpius as the bright star above centre. Anatares is just below Saturn. This is a single 30-second exposure at f/2.5 with the 24mm lens and Canon 5D MkII at ISO 6400.

Circumpolar star trails over the upper field of the Texas Star Party, May 13, 2015. The star party attracts hundreds of avid stargazers to the Prude Ranch near Fort Davis, Texas each year to enjoy the dark skies. The three observing fields are filled with telescopes from the basic to sophisticated rigs for astrophotography. I aimed the camera to look north over the field to capture the stars circling around Polaris in circumpolar trails over about 1 hour. Some cloud and haze obscured parts of the sky. Lights from cities to the north add the sky glow at right. The streaks at top are from the stars of the Big Dipper. This is a stack of 55 exposures, each 1 minute long, at f/2.8 with the 14mm lens and Canon 5D MkII at ISO 3200. The foreground comes from a single image in the series, masked and layered in Photoshop. The images were stacked using the Long Trails tapering effect with the Advanced Stacker Actions from Star Circle Academy. — Circumpolar star trails over the upper field of the Texas Star Party, May 13, 2015. I aimed the camera to look north over the field to capture the stars circling around Polaris in circumpolar trails over about 1 hour. Some cloud and haze obscured parts of the sky. Lights from cities to the north add the sky glow at right. The streaks at top are from the stars of the Big Dipper.
This is a stack of 55 exposures, each 1 minute long, at f/2.8 with the 14mm lens and Canon 5D MkII at ISO 3200. The foreground comes from a single image in the series, masked and layered in Photoshop. The images were stacked using the Long Trails tapering effect with the Advanced Stacker Actions from Star Circle Academy.

I extend my thanks to the organizers for the great event, and for the opportunity to speak to the group as one of the featured evening speakers. It was great fun!

March 15, 2015

The Ghostly Glows of a Truly Dark Sky

A truly dark sky isn’t dark. It is filled with glows both subtle and spectacular.

Last night, March 10, I drove up into the heart of the Gila Wilderness in southern New Mexico, to a viewpoint at 7,900 feet in altitude. I was in search of the darkest skies in the area. I found them! There was not a light in sight.

The featured image is a 180° panorama showing:

– the Zodiacal Light (at right in the west)
– the Milky Way (up from the centre, in the south, to the upper right)
– the Zodiacal Band (faintly visible running from right to left across the frame at top)
– the Gegenschein (a brightening of the Zodiacal Band at left of frame, in the east in Leo)

The Zodiacal Light, Zodiacal Band, and the Gegenschein are all part of the same phenomenon, glows along the ecliptic path – the plane of the solar system – caused by sunlight reflecting off cometary and meteoric dust in the inner solar system.

The Gegenschein, or “counterglow,” can be seen with the naked eye as a large and diffuse brightening of the sky at the spot exactly opposite the Sun. It is caused by sunlight reflecting directly back from comet dust, the scattering effect greatest at the point opposite the Sun.

The Zodiacal Light requires reasonably dark skies to see, but the fainter Zodiacal Band and Gegenschein require very dark skies.

Now is prime season for all of them, with the Moon out of the way, and the Zodiacal Light angled up high in the western as twilight ends. In March, the Gegenschein is now located in a relatively blank area of sky in southern Leo.

The Milky Way is much more obvious. Along the northern winter Milky Way here you can see dark lanes of interstellar dust, particularly in Taurus above and to the right of Orion. Red nebulas of glowing gas also lie along the Milky Way, such as Barnard’s Loop around Orion.

– Orion is at centre, in the south, with Canis Major and the bright star Sirius below and to the left of Orion. Canopus is just setting on the southern horizon at centre. It barely clears the horizon from 32° North latitude.

– To the right of Orion is Taurus and the Pleiades star cluster at the top of the Zodiacal Light pyramid.

– Venus is the bright object in the Zodiacal Light at right, in the west, while fainter Mars is below Venus.

– At far right, in the northwest, is the Andromeda Galaxy, M31.

– Jupiter is the bright object at upper left, in the east, in the Zodiacal Band, and near the Beehive star cluster.

– The Zodiacal Light, Band and Gegenschein all lie along the ecliptic, as do Mars, Venus and Jupiter.

Glows on the horizon are from distant SIlver City, Las Cruces and El Paso. The brighter sky at right is from the last vestiges of evening twilight. Some green and red airglow bands also permeate the sky.

I shot this March 10, 2015 from the summit of Highway 15, The Trail of the Mountain Spirits, that twists and winds through the Gila Wilderness.

It was a stunning night, clear, calm, and silent. Just me under the ghostly glows of a truly dark sky.

NOTE: I first published this March 11 but had to republish this blog March 15 after WordPress deleted the original post in a software bug. Thanks WordPress!

July 30, 2014

Mt Kobau Milky Way

The Milky Way towers over the pine trees and sagebrush of Mt. Kobau in the South Okanagan, BC.

It’s been a fine two nights renewing friendships and seeing stars at the summit of Mount Kobau near Osoyoos. I’ve not been here for a dozen years but the timing worked out this year for me to visit the annual Mt. Kobau Star Party, the first star party I attended back in the 1980s.

It’s a rough road to the summit but the reward is a beautiful landscape and skyscape.

The main image above is from Monday night and takes in the Milky Way from horizon to zenith, from Sagittarius to Cygnus. I used a 15mm lens and Canon 5D MkII riding on a new Sky-Watcher Star Adventurer tracking unit, which worked beautifully.

This image, similar to one I took a few nights ago at the Table Mountain Star Party, is a 360° panorama of the land and sky at the Kobau summit. It is a stitch of 8 segments, each 45-second exposures at ISO 6400 with the Canon 6D and 14mm Rokinon lens.

Unfortunately, it shows the light pollution glows from Osoyoos and Oliver that have grown over the last 3 decades and now impinge upon the Kobau skies.

This image is a tracked closeup of the Cygnus and Lyra area of the Milky Way, taken with a 50mm lens and the 5D Mark II riding on the Star Adventurer for a stack of five 10-minute exposures. It is rich in the red nebulosity of the Cygnus spiral arm and takes in the field that the Kepler satellite stared at for 4 years looking for alien planets.

I’m heading home but the star party continues all week, building to the weekend when most people will be attending, under prospects of clear skies and warm weather.

July 27, 2014July 27, 2014

Panoramas of the Summer Milky Way

The Milky Way spans the sky on a summer night at a dark-sky star party.

What a fabulous weekend! For the last few nights I’ve enjoyed the skies and hospitality of the Table Mountain Star Party in northern Washington state, near Oroville, just south of the Canada-US border. The site is the Eden Valley Guest Ranch, under superbly dark skies.

About 300 people, mostly from Washington, enjoyed getting under the Milky Way.

As I wandered around the telescope field I heard all kinds of excited comments in the dark: “Wow, look at that!” “Hey, take a look at the Swan Nebula!” “Want to see the Veil Nebula?”

I was impressed with the great mix of ages and demographics at the TMSP – it wasn’t just “old timers.” There were young families, couples, teens, even a pair of grannies pulled in for a look at the starry sky!

The summer Milky Way arches across the sky in these 360-degree “pans.”

But the other main feature is the green fingers of airglow rising out of the east (at left in the circular image above). Only the camera picked these up – the sky looked very dark to the eye. There’s even a faint magenta glow on the northern horizon (at top in the circular image) from aurora.

Both images capture the entire sky, in a panorama set I took using a 14mm Rokinon lens, shooting vertically for 8 segments at 45° spacings. Each frame was a 45-second exposure at f/2.8 and ISO 6400, on a standard tripod, no tracking.

I used PTGui software to stitch and blend the images, then Photoshop CC 2014 to finish them off.

The top image uses “equirectangular” projection; the bottom image “stereographic” projection for a fish-eye effect. Both take in the entire sky from horizon to horizon, plus a lot of ground, filled with red-lighted and happy observers.