Ophiuchus Archives

September 17, 2015December 23, 2015 by Bob King

Amateur Astronomer Chases Down Barnard’s Star – You Can Too!

It now covers 9 years (9 animation frames) from 2007 to 2015 (July). Nothing much has changed but for its location keeps moving north. For those looking to find it visually the arrowhead asterism to the south seen in the full frame image which is about a half degree wide and a third of a degree high. so fits a medium power telescope field of view. The galaxy near the bottom of the image is CGCG 056-003, a 15.6 magnitude galaxy some 360 million light-years distant and 85,000 light-years across. Credit: Rick Johnson

Tucked away in northern Ophiuchus and well-placed for observing from spring through fall is one of the most remarkable objects in the sky — Barnard’s Star. A magnitude +9.5 red dwarf wouldn’t normally catch our attention were it not for the fact that it speeds across the sky faster than any other star known.

Incredibly, you can actually see its motion with a small telescope simply by dropping by once a year for 2-3 years and taking note of its position against the background stars. For one amateur astronomer, recording its wandering ways became a 9-year mission.

This map shows the sky facing southeast around 10:30 p.m. local time in early June. Barnard's Star is located 1° NW of the 4.8-magnitude star 66 Ophiuchi on the northern fringe of the loose open cluster Melotte 186. Source: Stellarium — This map shows the sky facing south-southwest around 9 o’clock local time in late September. Barnard’s Star is located 1° NW of the 4.8-magnitude star 66 Ophiuchi on the northern fringe of the loose open cluster Melotte 186. Use the more detailed map below to pinpoint the star’s location. Source: Stellarium

Located just 6 light years from Earth, making it the closest star beyond the Sun except for the Alpha Centauri system, Barnard’s Star dashes along at 10.3 arc seconds a year. OK, that doesn’t sound like much, but over the course of a human lifetime it moves a quarter of a degree or half a Full Moon, a distance large enough to be easily perceived with the naked eye.

Barnard's Star would be an undistinguished red dwarf in Ophiuchus were it not for its rapid motion across the sky. It measures 1.9 times Jupiter's diameter and lies only 6 light-years from Eart — Barnard’s Star is a very low mass red dwarf star 1.9 times Jupiter’s diameter only 6 light-years from Earth in the direction of the constellation Ophiuchus the Serpent Bearer. Credit: Wikipedia with additions by the author

This fleet-footed luminary was first spotted by the American astronomer E.E. Barnard in 1916. With a proper motion even greater than the triple star Alpha Centauri, we’ve since learned that the star’s speed is truly phenomenal; it zips along at 86 miles a second (139 km/sec) relative to the Sun. As the stellar dwarf moves north, it’s simultaneously headed in our direction.

Based on its high velocity and low “metal” content, Barnard’s Star is believed to be a member of the galactic bulge, a fastness of ancient stars formed early on in the Milky Way galaxy’s evolution. Metals in astronomy refer to elements heavier than hydrogen and helium, the fundamental building blocks of stars. That’s pretty much all that was around when the first generation of suns formed about 100 million years after the Big Bang.

Generally, the lower a star’s metal content, the more ancient it is as earlier generations only had the simplest elements on hand. More complex elements like lithium, carbon, oxygen and all the rest had to be cooked up the earliest stars’ interiors and then released in supernovae explosions where they later became incorporated in metal-rich stars like our Sun.

All this to say that Barnard’s Star is an interloper, a visitor from another realm of the galaxy here to take us on a journey across the years. It certainly got the attention of Lincoln, Nebraska amateur Rick Johnson, who first learned of the famous dwarf in 1957.

Close-up map showing Barnard's Star's northward march every 5 years from 2015 to 2030. Your guide star, 66 Ophiuchi, is at lower left. Stars are numbered with magnitudes and a 15? scale bar is at lower right. North is up. The line through the two 12th-magnitude stars will help you gauge Barnard's movement. Click for larger map. — Close-up map showing Barnard’s Star’s position every 5 years from 2015 to 2030. Your guide star, 66 Ophiuchi, also shown on the first map, is at lower left. Stars are numbered with magnitudes and a 15 arc minute scale bar is at lower right. North is up. The line through the two 12th-magnitude stars will help you gauge Barnard’s movement in the coming few years. Click for a larger map.

“One of the first things I imaged was Barnard’s Star on the off chance I could see its motion,” wrote Johnson, who used a cheap 400mm lens on a homemade tracking mount. “Taking it a couple months later didn’t show any obvious motion, though I thought I saw it move slightly. So I took another image the following year and the motion was obvious.”

Many years later in 2005, Johnson moved to very dark skies, upgraded his equipment and purchased a good digital camera. Barnard’s Star continued to tug at his mind.

“Again one of my first thoughts was Barnard’s Star. The idea of an animation however didn’t hit until later, so my exposure times were all over the map. This made the first frames hard to match.” Later, he standardized the exposures and then assembled the individual images into a color animation.

This diagram illustrates the locations of the star systems closest to the sun. The year when the distance to each system was determined is listed after the system's name. NASA's Wide-field Infrared Survey Explorer, or WISE, found two of the four closest systems: the binary brown dwarf WISE 1049-5319 and the brown dwarf WISE J085510.83-071442.5. NASA's Spitzer Space Telescope helped pin down the location of the latter object. The closest system to the sun is a trio of stars that consists of Alpha Centauri, a close companion to it and Proxima Centauri. Credit: NASA / Penn State — This diagram illustrates the locations of the star systems closest to the Sun along with the dates of discovery. NASA’s Wide-field Infrared Survey Explorer, or WISE, found two of the four closest systems: the binary brown dwarf WISE 1049-5319 and the brown dwarf WISE J085510.83-071442.5. The closest system to the Sun is a trio of stars that consists of Alpha Centauri, a close companion to it and Proxima Centauri. Credit: NASA / Penn State

“Now the system is programed to take it each July,” he added. I’m automated, so its all automatic now.” Johnson said the Barnard video is his most popular of many he’s made over the years including short animations of the eye-catching Comet C/2006 M4 SWAN and Near-Earth asteroid 2005 YU55.

With Johnson’s wonderful animation in your mind’s eye, I encourage you to use the maps provided to track down the star yourself the next clear night. To find it, first locate 66 Ophiuchi (mag. 4.8) just above the little triangle of 4th magnitude stars a short distance east or left of Beta Ophiuchi. Then use the detailed map to star hop ~1° to the northwest to Barnard’s Star.

Barnard's Star is one of our galaxy's ancient ones with age of somewhere between 7 and 12 billion years — Barnard’s Star, a red dwarf low in metals, is very ancient with an age between 7 and 12 billion years. Like people, older stars slow down and Barnard’s is no exception with a rotation rate of 150 days. Heading in the Sun’s direction, the star will come closest to our Solar System around the year 11,800 A.D. at a distance of just 3.75 light years. Credit: NASA

It’s easily visible in a 3-inch or larger telescope. Use as high a magnification as conditions will allow to make a sketch of the star’s current position, showing it in relation to nearby field stars. Or take a photograph. Next summer, when you return to the field, sketch it again. If you’ve taken the time to accurately note the star’s position, you might see motion in just a year. If not, be patient and return the following year.

Most stars are too far away for us to detect motion either with the naked eye or telescope in our lifetime. Barnard’s presents a rare opportunity to witness the grand cycling of stars around the galaxy otherwise denied our short lives. Chase it.

November 28, 2014December 23, 2015 by David Dickinson

Here’s Your Sign: Are You an Ophiuchian?

It happens to all lovers of astronomy sooner or later.

I once had a friend who was excited about an upcoming conjunction of Saturn and Venus. They were passing closer than the apparent diameter of the Full Moon in the dawn sky, and you could fit ‘em both in the same telescopic field of view. I invited said friend to stop by at 5 AM the next morning to check this out. I was excited to see this conjunction as well, but not for the same reasons.

Said friend was into astrology, and I’m sure that the conjunction held a deep significance in their world view. Sure, I could have easily told them that ‘astrology is bunk,’ and the skies care not for our terrestrial woes… or I could carefully help guide this ‘at risk friend’ towards the true wonders of the cosmos if they were willing to listen.

We bring this up because this weekend, the Sun enters the constellation Ophiuchus, one of 13 modern constellations that it can appear in from our Earthly vantage point.

If you’re born from November 30^th to December 18^th, you could consider yourself an “Ophiuchian,” or being born under the sign of Ophiuchus the Serpent Bearer. But I’ll leave it up to you to decide what they might be like.

Seen at the Albany Park Zoo: Herpetology, or a modern day “serpent bearer?” Photo by author.

You might remember how the “controversy” of the 13^th sign made its news rounds a few years back. Hey, it was cool to at least see an obscure and hard to pronounce constellation trending on Twitter. Of course, this wasn’t news to space enthusiasts, and to modern astronomers, a ‘house’ is merely where you live, and a ‘sign’ is what you follow to get there.

The modern 88 constellations we use were formalized by the International Astronomical Union in 1922. Like political boundaries, they’re imaginary constructs we use to organize reality. Star patterns slowly change with time due to our solar system’s motion — and that of neighboring stars —about the galactic center.

Astrologers will, of course, counter that their craft follows a tropical scheme versus a sidereal cosmology. In the tropical system, ecliptic longitude 0 starts from the equinoctial point marking the beginning of spring in the northern hemisphere, and the zodiac is demarcated by 12 ‘houses’ 30 degrees on a side.

This neatly ignores the reality of our friend, the precession of the equinoxes. The Earth’s poles do a slow wobble like a top, taking about 26,000 years to make one turn. This means that in the sidereal scheme of things, our vantage point of the Sun’s position along the zodiac against the background stars if reference to our Gregorian calendar is slowly changing: live out a 72 year lifespan, and the constellations along the zodiac with respect to the Sun will have shifted about one degree due to precession.

Our changing pole star. Credit: Starry Night Education Software.

Likewise, the direction of the North and South Pole is changing as well. Though Polaris makes a good pole star now, it’ll become increasingly less so as our north rotational pole begins to pull away from it after 2100 A.D. To the ancient Egyptians, Thuban (Alpha Draconis) was the pole star.

Credit: Wikimedia Commons — Precession over time. Credit: Tfr000 under Wikimedia Creative Commons 3.0 license.

Astrology and astronomy also have an intimate and hoary history, as many astronomers up until the time of Kepler financed their astronomical studies by casting royal horoscopes. And we still use terms such as appulse, conjunction and occultation, which have roots in astrology.

But the science of astronomy has matured beyond considering whether Mercury in retrograde has any connection with earthly woes. Perhaps you feel that you’re unlucky in love and have a vast untapped potential… sure, me too. We all do, and that just speaks to the universal state of the human condition. Astrology was an early attempt by humanity to find a coherent narrative, a place in the cosmos.

But the rise of the Ophiuchians isn’t nigh. Astrology relented to astronomy because of the latter’s true predictive power. “Look here, in the sky,” said mathematician Urbain Le Verrier, “and you’ll spy a new planet tugging on Uranus,” and blam, Neptune was discovered. If the planets had any true influence on us, why didn’t astrologers manage to predict the same?

Combating woo such as astrology is never simple. In the internet era, we often find tribes of the like-minded folks polarized around electronic camp fires. For example, writing ‘astrology is woo’ for an esteemed audience of science-minded readers such as Universe Today will no doubt find a largely agreeable reception. We have on occasion, however, written the same for a general audience to a much more hostile reception. Often, it’s just a matter of being that lone but patient voice of rationalism in the woods that ultimately sinks in.

So, what’s the harm? Folks can believe whatever they want, and astrology’s no different, right? Well, the harm comes when people base life decisions on astrology. The harm comes when world leaders make critical decisions after consulting astrologers. Remember, Nancy and President Ronald Reagan conferred with astrologers for world affairs. It’s an irony of the modern age that, while writing a take down on astrology, there will likely be ads promoting astrology running right next to this very page. And while professional astronomers spend years in grad school, you can get a “PhD in Astrology” of dubious value online for a pittance. And nearly every general news site has a astrology page. Think of the space missions that could be launched if we threw as much money at exploration as we do at astrology as a society. Or perhaps astronomers should revert back to the dark side and resume casting horoscopes once again?

But to quote Spiderman, “with great power comes great responsibility,” and we promise to only use our astronomical powers for good.

What astronomers want you to know is that we’re not separate from the universe above us, and that the cosmos does indeed influence our everyday lives. And we’re not talking about finding your car keys or selling your house. We’re thinking big. The Sun energizes and drives the drama of life on Earth. The atoms that make you the unique individual that you are were forged in the hearts of stars. The ice that chills our drink may well have been delivered here via comet. And speaking of which, a comet headed our way could spell a very bad day for the Earth.

P_20130928_083416 — Don’t leave home without one… a travelling “pocket planetarium” circa 16th century seen at the Tampa Bay History Center. Photo by author.

All of these are real things that astronomy tells us about our place in the cosmos, whether you’re an Ophiuchian or a Capricorn. To paraphrase Shakespeare, the heavens may (seem to) blaze forth for the death of princes, but the fault lies not in the heavens, but ourselves. Don’t forget that, as James Randi says, “you’re a member of a proud species,” one loves to look skyward, and ultimately knows when to discard fantasy for reality.

January 25, 2014December 23, 2015 by Bob King

Lovejoy and X1 LINEAR: How to See Comets That Will Warm Up Your Mid-Winter Mornings

Comet Lovejoy still shows both an ion tail (blue) and dust tail in this photo taken Jan. 12 from Stixendorf, Austria. Credit: Michael Jaeger

My hands are still cold from the experience, but there’s no denying the pleasure I felt at seeing C/2013 R1 Lovejoy and C/2012 X1 LINEAR through the telescope this morning. Some comets fizzle, others fall apart, but these vaporous hunks have hung in there for months like steadfast friends that stick with you through hard times and good.While no longer visible with the naked eye, 50mm binoculars easily show it as a magnitude 7 fuzzy glow with a short, faint tail pointing up and away to the northwest. I had no difficulty seeing it even with a last quarter moon glaring in the south.

Comets Lovejoy and X1 LINEAR are both moving across northern Ophiuchus. This map shows the sky facing east about 1 hour 45 minutes before sunrise shortly before the start of morning twilight. Detailed map below. Stellarium — Comets Lovejoy and X1 LINEAR are neighbors in northern Ophiuchus this month and next. This map shows the sky facing east about 1 hour 45 minutes before sunrise shortly before the start of morning twilight. Tick marks show the comets’ position every 5 days. Click to enlarge. Detailed map below. Created with Chris Marriott’s SkyMap software.

Rising around 3 a.m., Lovejoy is best placed for viewing just before the start of dawn when it climbs to about 30 degrees altitude in Ophiuchus. Lucky for us, Lovejoy will spend the next few mornings very close to the easy naked eye star 72 Ophiuchi, located 3 fists held at arm’s length to the lower right of brilliant Vega. It’s not often that a fairly bright comet passes this close to a helpful guide star. Don’t miss this easy catch. Soon the moon won’t be any trouble either as it skedaddles eastward and dwindles to a crescent in the coming mornings.

This deeper map shows stars to about magnitude 8. Although both comets appear to be getting lower every morning, the seasonal drift of the star to the west will keep them in good view for the next few months. Stellarium — This deeper map shows stars to about magnitude 8. Although both comets appear to be getting lower every morning, the westward seasonal drift of the stars will keep them in good view for the next few months. Click to enlarge. Created with Chris Marriott’s SkyMap software

Telescopic views of Lovejoy show a much diminished coma and tail compared to its heyday in early December. Still, the nucleus remains bright and very condensed within the 3′ diameter gauzy coma; a faint and silky tail 2/3 of a degree long flowed across the field of view of my 15-inch (37-cm) reflector like a bride’s train. According to the excellent Weekly Information about Bright Comets site maintained by Seiichi Yoshida, Lovejoy should glow brighter than magnitude 8, what I consider the “bright” comet cutoff, through early February. Given that Lovejoy remains the brightest predicted comet visible till summer, show it some love the next clear night.

Comet C/2012 X1 LINEAR shows a green coma from fluorescing gases and a short tail in this photo made on Jan. 15, 2014. Credit: Rolando Ligustri

If Lovejoy’s a fading celebrity, X1 LINEAR suffered a mid-life crisis and snapped out of it with a whole new attitude. Like Comet Holmes in 2007, it catapulted in brightness overnight in last October, blossoming from a 14th magnitude blip into a bright, expanding puffball briefly visible in ordinary binoculars. As expected, the comet soon faded. But on its return to obscurity, X1 surprised again, re-brightening and growing a short tail. Now it’s humming along at 9th magnitude thank you very much. You’ll find it gliding across northern Ophiuchus not far from Lovejoy (more about that in a minute).

Very different appearance of C/2012 X1 LINEAR during outburst on Oct. 21, 2013. Credit: Ernesto Guido, Martino Nicolini & Nick Howes

My binoculars won’t show the comet but a 6-inch telescope will do the trick. Overall weaker in appearance than Lovejoy, X1 LINEAR has a slightly larger, more diffuse coma, brighter core and a short, faint tail pointing to the northwest. The comet will remain a fine target for smaller scopes through early March when it’s predicted to glow between magnitude 8 and 9.

Comets Lovejoy and X1 LINEAR will be closest together on the morning of Feb. 6 CST. Notice that they'll be in the company of numerous deep sky objects. Looks like a morning's worth of observing to me! Created with Chris Marriott's SkyMap software — Comets Lovejoy and X1 LINEAR will be closest together on the morning of Feb. 6 CST. A plethora of deep sky objects near them will make for a complete morning’s worth of sky watching! Click to enlarge. Created with Chris Marriott’s SkyMap software

Looking at the maps, you’ll see that our two comets’ paths intersect. While they won’t overlap on the same morning, Lovejoy and X1 LINEAR will be in conjunction on Feb. 6 when they’ll be just 2 degrees apart. Get that camera ready! Guided telephoto and wide-field telescopes will be perfect for catching this unusual duet.

Before I sign off, don’t forget all the other good morning stuff: Mars hovers above Spica high in the south-southwestern sky, Saturn invites inspection in the southeast and Venus is back in view in the east-southeast 45 minutes before sunup. A delicate crescent moon shines near Venus on Jan. 28 and 29. Such riches.

January 24, 2011January 19, 2016 by Nancy Atkinson

The Real News about Ophiuchus: There’s a Runaway Star Plowing Through It

The blue star near the center of this image is Zeta Ophiuchi, a runaway star plowing through the constellation Ophiuchus. Credit: NASA/JPL-Caltech/UCLA

Lots of folks seem to be up in arms about the “new” sign in the zodiac, Ophiuchus, and the news that all the star signs are no longer in sync with the actual constellations. Of course, *most* of us already knew that news is centuries old, and that the zodiac has no effect whatsoever on our lives and it never has (most readers of Universe Today, anyway!) Now for some real news about Ophiuchus: NASA’s Wide-field Infrared Survey Explorer, or WISE has found a massive, runaway star, called Zeta Ophiuchi that is plowing through a cloud of space dust in Ophiuchus. The result is a brilliant bow shock, seen here as a yellow arc in this stunning new image.
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