Astrophoto – Stephens Memorial Observatory

Our active Sun

September 10, 2021StephensAstroLeave a comment

The Sun, showing several sunspots/active regions. This image was made at 3:43 PM EDT/7:43 PM UTC on September 10, 2021 using the photographer’s personal reflecting telescope with safe solar filter, and DSLR camera body. Credit: James Guilford

After a long period of quiet during our Sun’s fairly predictable 11-year activity cycle, things have been happening. What was a bright, clear disk has become speckled with sunspots of late. The increased activity brings with it the chance of Earth-directed coronal mass ejections, or CMEs, which result in solar storms when they collide with our home planet’s magnetic field. Auroras, or “northern lights” for us, are one potential result of solar storms. The less pleasant effects can include disruption of radio communications and satellite operation, all the way to electrical grid failures at the extreme!

Several recent CMEs have missed Earth but one is headed in our direction as this blog entry is being written. According to SpaceWeather.com, “{A} CME is on the way following an explosion in the magnetic canopy of sunspot AR2864 on Sept. 8th. NOAA analysts believe Earth could experience a glancing blow or near miss late on Sept. 11th.” Those favored with clear skies and a good view to the north may want to be on the lookout for aurora, but the odds aren’t favorable … this time!

Here are two photos of Sun, shot by Stephens’ Director James Guilford, at 3:43 PM EDT (7:43 PM UTC). The first image shows the full solar disk. Notice not only the dark sunspots but also the lighter-colored “splotches” of additional active solar regions, most visible near the edges of the disk.

The second image is cropped to show the major concentration of the day’s sunspots with their official numerical designations. Both images have been color tinted.

A tightly-cropped portion of the day’s full-disk image shows three sunspot groups: AR 2866, AR 2868, and AR 2869. Sunspots only appear to be dark because they are significantly “cooler” than the surrounding solar atmosphere; they are actually quite hot. Sun’s shining photosphere has a temperature of 5,800 degrees Kelvin while sunspots have temperatures of around 3,800ºK (6,380℉). Nearly all of the dark features seen here are larger than planet Earth. Credit: James Guilford

Centaurus A captured by the Dark Energy Camera

August 31, 2021StephensAstroLeave a comment

The galaxy Centaurus A, which lies over 12 million light-years away in the direction of the southern-hemisphere constellation Centaurus (The Centaur), is the leading light of this striking image. This image provides a spectacular view of the luminous glow of stars and dark tendrils of dust that hide the bright center of the galaxy. This dust is the result of a past galactic collision, in which a giant elliptical galaxy merged with a smaller spiral galaxy. As well as large amounts of gas and dust, Centaurus A’s dust lane contains widespread star formation, as indicated by the red clouds of hydrogen and by the large numbers of faint blue stars visible at each end of the dust lane.

Credit: CTIO/NOIRLab/DOE/NSF/AURA

A stellar butterfly

July 30, 2020StephensAstro1 Comment

This highly detailed image of the fantastic NGC 2899 planetary nebula was captured using the FORS instrument on ESO’s Very Large Telescope in northern Chile. This object has never before been imaged in such striking detail, with even the faint outer edges of the planetary nebula glowing over the background stars. Credit: ESO

Resembling a butterfly with its symmetrical structure, beautiful colors, and intricate patterns, this striking bubble of gas — known as NGC 2899 — appears to float and flutter across the sky in this new picture from the European Southern Observatory’s Very Large Telescope (VLT). This object has never before been imaged in such striking detail, with even the faint outer edges of the planetary nebula glowing over the background stars.

NGC 2899’s vast swathes of gas extend up to a maximum of two light-years from its center, glowing brightly in front of the stars of the Milky Way as the gas reaches temperatures upwards of ten thousand degrees. The high temperatures are due to the large amount of radiation from the nebula’s parent star, which causes the hydrogen gas in the nebula to glow in a reddish halo around the oxygen gas, in blue.

This object, located between 3000 and 6500 light-years away in the Southern constellation of Vela (The Sails), has two central stars, which are believed to give it its nearly symmetric appearance. After one star reached the end of its life and cast off its outer layers, the other star now interferes with the flow of gas, forming the two-lobed shape seen here. Only about 10–20% of planetary nebulae [1] display this type of bipolar shape.

Astronomers were able to capture this highly detailed image of NGC 2899 using the FORS instrument installed on UT1 (Antu), one of the four 8.2-meter telescopes that make up ESO’s VLT in Chile. Standing for FOcal Reducer and low dispersion Spectrograph, this high-resolution instrument was one of the first to be installed on ESO’s VLT and is behind numerous beautiful images and discoveries from ESO. FORS has contributed to observations of light from a gravitational wave source, has researched the first known interstellar asteroid, and has been used to study in depth the physics behind the formation of complex planetary nebulae.

This image was created under the ESO Cosmic Gems program, an outreach initiative to produce images of interesting, intriguing or visually attractive objects using ESO telescopes, for the purposes of education and public outreach. The program makes use of telescope time that cannot be used for science observations. All data collected may also be suitable for scientific purposes, and are made available to astronomers through ESO’s science archive.

Excitement surrounds comet C/2020 F3 (NEOWISE)

July 16, 2020StephensAstroLeave a comment

Purity and Pollution. Comet C/2020 F3 NEOWISE floats serenely among stars above clouds glowing brightly from light pollution. Photo by James Guilford.

Comet C/2020 F3 (NEOWISE) was, for us in North America, a predawn object requiring exceptional dedication for observing. In the second week of July, the comet had moved enough in its orbit to become visible in the evening sky — from late twilight to about 11 p.m. Unfortunately, cloudy nights have been the rule lately so opportunities have been few.

On Wednesday night, July 15, the sky forecast was a bit shaky but it turned out the sky cleared enough to allow C/2020 F3 to be seen. I raced off to an observing site some 25 minutes away from home, popular with sunset watchers and, occasionally, comet spotters. Arriving at the site I found the place mobbed, the parking lot nearly full, by scores of would-be comet viewers. Unfortunately, the comet was pretty much at the low end of naked-eye visibility. Light pollution reduced contrast between comet and background sky to make the object nearly invisible — binoculars were needed. It’s likely most of those in attendance never saw the comet.

Entitled “Purity and Pollution,” this picture (a single exposure of 8 seconds) shows a pristine wonder of the night sky floating serenely amongst the stars, clouds glowing brightly below illuminated by artificial light pollution. If we were only more careful with our artificial light, we’d save plentiful energy (and money) and gain back our starry skies as a bonus!

C/2020 F3 (NEOWISE) will be gracing our night skies for the next week or so and I hope to have more than one opportunity to record the event before it is gone. The next apparition of this comet is expected in about 6,800 years.

July Fourth weekend brought sky events great and small

July 6, 2020July 9, 2020StephensAstroLeave a comment

Little difference can be seen between an earlier stage and the maximum eclipse state of the July 4 - 5, 2020 penumbral lunar eclipse. Photos by James Guilford. — Little difference can be seen between an earlier stage and the maximum eclipse state of the July 4 – 5, 2020 penumbral lunar eclipse. The images were made with identical camera and Photoshop settings. Photos by James Guilford.

There was much ballyhoo surrounding the penumbral lunar eclipse that would take place the night of July 4 – 5, 2020. We joined in just to explain a little about what was going on and what might be expected. Penumbral lunar eclipses take place when the Moon passes through the thin outer shadow Earth casts out into space; they are often very subtle, slight, and in this case, nearly undetectable. Just witness the photo above that shows the Full Buck Moon about one-half hour before maximum eclipse and the Moon at maximum. Casual observers saw no change across the entire event and it’s hard for us to see the difference even in photos that can be made to emphasize features! So we apologize if you waited up to see what we called the “subtle” eclipse but, if you did, you saw a beautiful Full Moon!

Then there was the much-less-promoted Sunday night, July 5, conjunction of Earth’s Moon, with planets Jupiter and Saturn… a lovely sight! We went out to photograph it an hour after moonrise and spied a brilliant orange Moon lighting up the scattered clouds with Jupiter shining through and Saturn making a somewhat dimmer appearance. A conjunction is when two or more celestial objects appear close together in our skies — emphasis on appear since Moon, Jupiter, and Saturn are separated by hundreds of millions of miles. We were surprised to see, in the photo below, that even Jupiter’s four Galilean Moons can be seen. The stars and planets appear oblong or as short streaks due to Earth’s rotation and the length of the camera exposure.

Conjunction of Earth's Moon, with planets Jupiter (bright dot above), and Saturn (less bright dot to the left at the edge of a cloud), the night of July 5, 2020. Photo by James Guilford. — Conjunction of Earth’s Moon, with planets Jupiter (bright dot above), and Saturn (less bright dot to the left at the edge of a cloud), the night of July 5, 2020. Photo by James Guilford.

Recalling an outburst: Comet 17P/Holmes

May 7, 2020StephensAstroLeave a comment

Photo: Comet 17P/Holmes by James Guilford — Comet Redux. Reprocessing old images shot through the Stephens Observatory telescope shows Comet 17P/Holmes as it appeared October 28, 2007. The two dots are bright stars shining through the comet’s coma. Photo by James Guilford.

Back in 2007 astronomers were excited by a comet known as 17P/Holmes. What was so exciting was that the seemingly ordinary visitor from distant parts of the Solar System suddenly put on a great show. In October, the usually dim 17P/Holmes changed from an unremarkable telescopic object to become visible to the unaided eye, appearing as a yellow “star” in constellation Perseus. It was briefly the largest object in the Solar System. The outburst was believed to be similar to one that took place in 1892 making it visible to amateur astronomer Edwin Holmes, credited with its discovery on November 6 of that year. The reason for the sudden brightening or outbursts remains unknown.

I used my little Canon Rebel XT digital camera attached to the vintage Cooley Telescope at Stephens and attempted to capture images of the comet. The effort and the camera were pretty primitive compared with what we can do now but I got some images and they were the best I could manage at the time. Comet 17P/Holmes faded from visibility over the next several weeks. The somewhat odd appearance of the comet — no classic head and tail — is the result of our perspective: looking straight down its tail instead of from the side.

Recently I viewed a television show about comets and the strange behavior of 17P/Holmes was discussed. That program reminded me of the 2007 apparition and to look at my old images. There wasn’t much image data to work with but I reprocessed what I have and produced a new image a bit better than my first try; that image, shot through our old telescope, appears above.

The “P” in the comet’s designation stands for periodic, meaning after a period of time 17P will return to loop, once again, around Sun. In March 2014 (a seven-year period) the loop was made without an outburst. The next close approach to our Sun, perihelion, will take place on February 19, 2021. Will we be treated to another show?

— James Guilford

Celebrating the 30th anniversary of the Hubble Space Telescope

April 25, 2020StephensAstroLeave a comment

This image is one of the most photogenic examples of the many turbulent stellar nurseries the NASA/ESA Hubble Space Telescope has observed during its 30-year lifetime. The portrait features the giant nebula NGC 2014 and its neighbor NGC 2020 which together form part of a vast star-forming region in the Large Magellanic Cloud, a satellite galaxy of the Milky Way, approximately 163,000 light-years away.

We appreciate you, Luna

October 7, 2019October 7, 2019StephensAstroLeave a comment

Photo: First Quarter Moon, October 5, 2019. — Our First-Quarter Moon on International Observe the Moon Night, as seen through the Stephens telescope at 9:04 PM EDT. iPhone SE at eyepiece.

Our October 5 Open Night was the local event of the International Observe the Moon Night — an annual occurrence meant that encourages observation, appreciation, and understanding of our Moon and its connection to planetary science and exploration. Over the course of the night at Stephens Memorial Observatory some 34 enthusiastic and inquisitive visitors attended and were treated to beautiful and unusual views of Earth’s Moon and planet Saturn.

Unusual? The earliest visitors arrived just as the telescope was set to go … with the sky still bright with twilight. The Moon appeared light and against a power-blue sky background instead of the usual darkness of space. Saturn, invisible to the eye in the bright sky, was also viewed through the telescope in surprising detail.

Zooming in on the previous image: That dot in the center of dark-floored crater Alphonsus is its central peak. Over the course of two hours sun rose over that pinnacle making it brighter, and other features began to emerge as we watched. Alphonsus slightly overlaps the crater Ptolemaeus.

After darkness fell enthusiastic visitors took turns looking at a crater and watching a mountain peak become illuminated at sunrise on the Moon! It was a fine night appreciating a sight too often ignored: the wonder of Luna, our nearest neighbor in space.

Peaking this weekend: Orionid meteors aplenty!

October 20, 2017October 20, 2017StephensAstroLeave a comment

Photo: Fireball Meteor, Oct. 20, 2017. Credit: NASA/All-Sky Fireball Network — A Grand Orionid Fireball Meteor Imaged over Hiram Friday, October 20. Credit: NASA/All-Sky Fireball Network

Earth is entering a stream of debris from Halley’s Comet, source of the annual Orionid meteor shower. Thursday night, NASA’s network of all-sky meteor cameras detected 23 Orionid fireballs over the USA –meteors that flare brighter than the planet Venus shines– a result of comet dust hitting the atmosphere at speeds exceeding 65 km/s (145,000 mph). Among several fireballs recorded by the Fireball Network camera on the Hiram campus was the grand meteoric streak pictured above; that fireball was also recorded by the camera located at the Allegheny Observatory in Pittsburgh in the wee hours of Friday morning. Forecasters expect the shower to peak on Oct. 21-22 with as many as 25 meteors per hour. The meteor shower is called “Orionid” because the “falling stars” appear to originate from the vicinity of our sky occupied constellation Orion. Visit Spaceweather.com for observing tips and sky maps. — From a report by Spaceweather.com plus local contribution.

Weather conditions may be best for us overnight Friday as the Orionids shower builds towards its peak. https://www.accuweather.com/

Spectacular views of Earth’s Moon

October 1, 2017StephensAstroLeave a comment

Photo: Mare Imbrium region of Earth's Moon. Credit: James Guilford/Stephens Memorial Observatory — Mare Imbrium and Crater Copernicus. Credit: James Guilford/Stephens Memorial Observatory

We hosted our September Open Night as scheduled on the 30th with Earth’s Moon as our primary subject. The sky was (for once) completely clear of clouds and full of stars when we opened the dome for the 9:00 start. In all, 19 folks from small children to senior citizens attended and enjoyed spectacular views of our nearest neighbor in space. Two or three individuals attempted smart phone photography of the Moon with varying degrees of success. We also observed the Andromeda Galaxy and the Perseus Double Cluster. The image above was made just before we closed up and has been corrected for the telescope’s optical “flipping” of the image. Camera used was a Canon EOS 7D equipped with a 50mm lens and held to the telescope’s massive eyepiece. We will look at the Moon again October 28 when we celebrate the annual International Observe the Moon Night. See you then?