David Dickinson, Author at Universe Today

September 3, 2014December 23, 2015 by David Dickinson

Get Set for the Super (or Do You Say Harvest?) Full Moon 3 of 3 for 2014

Last month's supermoon within 24 hours of perigee. Credit: Blobrana

Time to dust off those ‘what is a perigee Full Moon’ explainer posts… the supermoon once again cometh this weekend to a sky near you.

Yes. One. More. Time.

We’ve written many, many times — as have many astronomy writers — about the meme that just won’t die. The supermoon really brings ‘em out, just like werewolves of yore… some will groan, some will bemoan the use of a modernized term inserted into the common astronomical vernacular that was wrought by an astrologer, while others will exclaim that this will indeed be the largest Full Moon EVER…

But hey, it’s a great chance to explain the weird and wonderful motion of our nearest natural neighbor in space. Thanks to the Moon, those astronomers of yore had some great lessons in celestial mechanics 101. Without the Moon, it would’ve been much tougher to unravel the rules of gravity that we take for granted when we fling a probe spaceward.

The Moon reaches Full on Tuesday, September 9^that 1:38 Universal Time (UT), which is 9:38 PM EDT on the evening of the 8^th. The Moon reaches perigee at less than 24 hours prior on September 8^th at 3:30 UT — 22 hours and 8 minutes earlier, to be precise — at a distance 358,387 kilometres distant. This is less than 2,000 kilometres from the closest perigee than can occur, and 1,491 kilometres farther away than last month’s closest perigee of the year, which occurred 27 minutes prior to Full Moon.

A Proxigean or Perigee Full “Supermoon” as reckoned by our preferred handy definition of “a Full Moon occurring within 24 hours of perigee” generally occurs annually in a cycle of three over two lunar synodic periods, and moves slowly forward by just shy of a month through the Gregorian calendar per year. The next cycle of “supermoons” starts on August 30^th, 2015, and you can see our entire list of cycles out through 2020 here.

What’s the upshot of all this? Well, aside from cluttering inboxes and social media with tales of the impending supermoon this weekend, the rising Moon will appear 33.5’ arc minutes in diameter as opposed to its usually quoted average of 30’ in size. And remember, that’s in apparent size as seen from our Earthly vantage point… can you spy a difference from one Full Moon to the next? Fun fact: the rising Moon is actually farther away from you to the tune of about one Earth radius than when it’s directly overhead at the zenith.

Fed up with supermoon-mania? The September Full Moon also has a more pedestrian name: The Harvest Moon. Actually, this is the Full Moon that falls nearest to the September Equinox, marking the start of the astronomical season of Fall in the northern hemisphere and Spring in the southern. In the current first half of the 21st century, the September Equinox falls on the 22^nd or 23^rd, meaning that the closest Full Moon (and thus the Harvest Moon) can sometimes fall in October, as last happened in 2009 and will occur again in 2017. In this instance, the September Full Moon would then be referred to as the Corn Moon as reckoned by the Algonquins, and is occasionally referred to as the Drying Grass Moon by Sioux tribes. In 2014, the Harvest Full Moon “misses” falling in October by about 32 hours!

The waning gibbous Moon of July 14th, 2014- shortly after the first supermoon of the year. Credit: Blobrana.

So, why is it known as the Harvest Moon? Well, in the age before artificial lighting (and artificial light pollution) the rising of the Full Moon as the Sun sets allowed for a few hours of extra illumination to bring in crops. In October, the same phenomenon gave hunters a few extra hours to track game by the light of the Full Hunters Moon, both essential survival activities before the onset of the long winter.

And that Full Harvest Moon seems to “stick around” on successive evenings. This is due to the relatively shallow angle of the evening ecliptic to the eastern horizon as seen from mid-northern latitudes in September.

The rising Full Moon on the evening of September 8th as seen from latitude 40 degrees north. Note the shallow angle of the ecliptic. Created using Stellarium.

Here’s a sample of rising times for the Moon this month as seen from Baltimore, Maryland at 39.3 degrees north latitude:

Saturday, September 6^th: 5:43 PM EDT

Sunday, September 7^th: 6:23 PM EDT

Monday, September 8^th: 7:05 PM EDT

Tuesday, September 9^th: 7:44 PM EDT

Wednesday, September 10^th: 8:22 PM EDT

Note the Moon rises only ~40 minutes later on each successive evening.

The Full Harvest Moon of 2013 plus aircraft. Credit: Stephen Rahn.

We’re also headed towards a “shallow year” in 2015, as the Moon bottoms out relative to the ecliptic and only ventures 18 degrees 20’ north and south of the celestial equator at shallow minimum. This is due to what’s known as the Precession of the Line of Apsides as the gravitational pull of the Sun slowly drags the orbit of the Moon round the earth once every 8.85 years. The nodes where the ecliptic and path of the Moon meet — and solar and lunar eclipses occur — also move slowly in an opposite direction of the Moon’s motion, taking just over twice as long as the Precession of the Line of Apsides to complete one revolution around the ecliptic at 18.6 years. This is one of the more bizarre facts about the motion of the Moon: its orbital tilt of 5.1 degrees is actually fixed with respect to the ecliptic as traced out by the Earth’s orbit about the Sun, not our rotational axis. Native American and ancient Northern European knew of this, and the next “Long Night’s Moon” also called a “Lunar Standstill” when the Moon rides high in the northern hemisphere sky is due through 2024-2025.

The footprint of the September 11th occultation of Uranus. Credit: Occult 4.0.

And to top it off, the Moon occults Uranus just two days after Full on September 11^th as seen from northeastern North America, Greenland, Iceland and northern Scandinavia. We’re in a cycle of occultations of Uranus by the Moon from late 2014 through 2015, and this will set the ice giant up for a spectacular close pass, and a rare occultation of the planet for a remote region in the Arctic during the October 8^th total lunar eclipse…

More to come!

September 2, 2014December 23, 2015 by David Dickinson

Hunting for “Minimoons” Orbiting Earth

It’s an engaging thought experiment.

What if Earth had multiple moons? Our world has one large natural satellite, just over a quarter the diameter, 1/50th the volume, and less than 1/80th the mass of our fair world. In fact, the Earth-Moon system has sometimes been referred to as a “binary planet,” and our Moon stands as the largest natural satellite of any planet — that is, if you subscribe to bouncing Pluto and Charon out of “the club” — in contrast to its primary of any moon in our solar system.

But what if we had two or more moons? And are there any tiny “moonlet” candidates lurking out there, awaiting discovery and perhaps exploration?

While historical searches for tiny secondary moons of the Earth — and even “moons of our Moon” — have turned up naught, the Earth does indeed capture asteroids as temporary moons and eject them back into solar orbit from time to time.

Now, a recent paper out of the University of Hawaii written in partnership with the SETI Institute and the Department of Physics at the University of Helsinki has looked at the possible prospects for the population of captured Near-Earth asteroids, and the feasibility of detecting these with existing and future systems about to come online.

The hunt for spurious moons of the Earth has a fascinating and largely untold history. Arthur Upgren’s outstanding book Many Skies devotes an entire chapter to the possible ramifications of an Earth with multiple moons… sure, more moons would be a bane for astrophotographers, but hey, eclipses and transits of the Sun would be more common, a definite plus.

In 1846, astronomer Frederic Petit announced the discovery of a tiny Earth-orbiting moon from Toulouse observatory. “Petit’s Moon” was said to orbit the Earth once every 2 hours and 44 minutes and reach an apogee of 3,570 kilometres and a perigee of just 11.4 (!) kilometres, placing it well inside the Earth’s atmosphere on closest approach.

A slightly more believable claim came from astronomer Georg Waltemath in 1898 for a moon 700 kilometres in size — he claimed it was, of course, a very dark body and not very easily visible — orbiting the Earth at about 2.5 times the distance of the Moon. Waltemath even made an announcement of his discovery, and claimed to have found a third moon of the Earth for good measure.

And a much more dubious claim came from the astrologer Walter Gornold in 1918 of a secondary moon, dubbed Lilith. Apparently, then (as now) astrologers never actually bothered to look at the skies…

Turns out, our large Moon makes a pretty good goaltender, ejecting —and sometimes taking a beating from — any tiny second moon hopeful. Of course, you can’t blame those astronomers of yore entirely. Though none of these spurious moons survived the test of observational verification, these discoveries often stemmed from early efforts to accurately predict the precise motion of the Moon. Astronomers therefore felt they were on the right track, looking for an unseen perturbing body.

Fast forward to the 21^st century. Quasi-moons of the Earth, such as 3753 Cruithne, have horseshoe-shaped orbits and seem to approach and recede from our planet as both orbit the Sun. Similar quasi-moons of Venus have also been discovered.

And even returning space junk can masquerade as a moon of Earth, as was the case of J002E3 and 2010 QW1, which turned out to be boosters from Apollo 12 and the Chinese Chang’e-2 missions, respectively.

What modern researchers are looking for are termed Temporarily Captured Orbiters, or TCOs. The study notes that perhaps an average of a few dozen asteroids up to 1 to 2 metres in size are in a “steady state” population that may be orbiting the Earth at any given time on an enter, orbit, and eject sort of conveyor belt. Estimates suggest that a large 5 to 10 metre asteroid is captured every decade so, and a 100 metre or larger TCO is temporarily captured by the Earth every 100,000 years. The study also estimates that about 1% occasionally hit the Earth. And though it wasn’t a TCO, the ability to detect an Earthbound asteroid before impact was demonstrated in 2008 with the discovery of 2008 TC3, less than 24 hours prior to striking in the Sudanese desert.

“There are currently no projects that are solely looking for minimoons at this time,” lead researcher Bryce Bolin of the University of Hawaii told Universe Today. “There are several surveys, such as PanSTARRS, the Catalina Sky Survey and the Palomar Transit Factory that are currently in operation that have the capability of discovering minimoons.”

We’re getting better at this hazardous asteroid detection business, that’s for sure. The researchers modeled paths and orbits for TCOs in the study, and also noted that collections may “clump” at the anti-sunward L2 opposition point, and the L1 sunward point, with smaller distributions located at the east and west quadrature points located 90 degrees on either side of the Earth. The L2 point in particular might make a good place to start the search.

Ironically, systems such as LINEAR and PanSTARRS may have already captured a TCO in their data and disregarded them in their quest for traditional Near Earth Objects.

“Surveys such as PanSTARRS/LINEAR utilize a filtration process to remove artifacts and false positives in the data as it gets processed through the data pipeline,” Researcher Bryce Bolin told Universe Today. “A common method is to apply a rate of motion cut… this is effective in eliminating many artifacts (which) tend to have a rate of motion as measured by the pipeline which is very high.”

Such systems aren’t always looking for fast movers near Earth orbit that can produce a trail or streak which may reassemble space junk or become lost in the gaps over multiple detection devices. And speaking of which, researchers note that Arecibo and the U.S. Air Force’s Space Surveillance System may be recruited in this effort as well. To date, one definite TCO, named 2006 RH120 has been documented orbiting and departing from the vicinity of the Earth, and such worldlets might make enticing targets for future manned missions due to their relatively low Delta-V for arrival and departure.

Future asteroid mission. Credit: NASA — An artist’s concept of a possible future asteroid mission near Earth. Credit: NASA.

PanSTARRS-2 saw first light last year in 2013, and is slated to go online for full science operations by the end of 2014. Eventually, the PanSTARRS system will employ four telescopes, and may find a bevy of TCOs. The researchers estimate in the study that a telescope such as Subaru stands a 90% chance of nabbing a TCO after only five nights of dedicated sweeps of the sky.

Finally, the study also notes that evidence miniature moonlets orbiting Earth may lurk in the all sky data gathered by automated cameras and amateur observers during meteor showers. Of course, we’re talking tiny, dust-to-pebble sized evidence, but there’s no lower limit as to what constitutes a moon…

And so, although moons such a “Lilith” and “Petit’s Moon” belong to the annuals of astronomical history, temporary “minimoons” of Earth are modern realities. And as events such as Chelyabinsk remind us, it’s always worthwhile to hunt for hazardous NEOs (and TCOs) that may be headed our way. Hey, to paraphrase science fiction author Larry Niven: unlike the dinosaurs, we have a space program!

Read more about the fascinating history of moons that never were and more in the classic book The Haunted Observatory.

August 28, 2014December 23, 2015 by David Dickinson

Observing Neptune: A Guide to the 2014 Opposition Season

Never seen Neptune? Now is a good time to try, as the outermost ice giant world reaches opposition this weekend at 14:00 Universal Time (UT) or 10:00 AM EDT on Friday, August 29^th. This means that the distant world lies “opposite” to the Sun as seen from our Earthly perspective and rises to the east as the Sun sets to the west, riding high in the sky across the local meridian near midnight.

2014 finds Neptune shining at magnitude +7.6 in the constellation of Aquarius. Unfortunately, the planet is too faint to be seen with the naked eye, but can be sighted using a good pair of binoculars if know exactly where to look for it. Though the telescope, Neptune exhibits a tiny blue-gray disk 2.4” across — 750 “Neptunes” would fit across the apparent diameter of the Full Moon — that’s barely discernible. Don’t be afraid to crank up the magnification in your quest. We’ve found Neptune on years previous by patently examining suspect stars one by one, looking for the one in the field that stubbornly refuses to focus to a star-like point. Make sure your optics are well collimated to attempt this trick. Neptune will exhibit a tiny fuzzy disk, much like a second-rate planetary nebula. In fact, this is where “planetaries” get their moniker, as the pesky deep sky objects resembled planets in those telescopes of yore…

Looking eastward — The position of Neptune, looking eastward on the night of opposition around an hour after sunset. Created using Stellarium.

The 1846 discovery of Neptune stood as a vindication of the (then) new-fangled theory of Newtonian gravitational dynamics. Uranus was discovered just decades before by Sir William Hershel in 1781, and it stubbornly refused to follow predictions concerning its position. French astronomer Urbain Le Verrier correctly assumed that an unseen body was tugging on Uranus, predicted the position of the suspect object in the sky, and the race was on. On the night of September 24th, Heinrich Louis d’Arrest and Johann Gottfried Galle observing from the Berlin observatory became the first humans to gaze upon the new world referring to it as such. Did you know: Galileo actually sketched Neptune near Jupiter in 1612? And those early 18^th century astronomers got a lucky break… had Neptune happened to have been opposite to Uranus in its orbit, it might’ve eluded discovery for decades to come!

It’s also sobering to think that Neptune has only recently completed a single orbit of the Sun in 2011 since its discovery. Opposition of Neptune occurs once every 368 days, meaning that opposition is slowly moving forward by about three days a year on our Gregorian calendar and will soon start occurring in northern hemisphere Fall.

Neptune and a one degree field (green) circle. Note that it passes the bright naked eye star Sigma Aquarii on September 15th. Created using Starry Night Education Software.

Now for the “wow factor” of what you’re actually seeing. Though tiny, Neptune is actually 24,622 kilometres in radius, and is 58 times as big as the Earth in volume and over 17 times as massive. Neptune is 29 A.U.s or 4.3 billion kilometres from Earth at opposition, meaning the light we see took almost four hours to transit from Neptune to your backyard.

Neptune is currently south of the equator, and won’t be north of it again until 2027.

Next month, keep an eye on Neptune as it passes less than half a degree north of the +4.8 magnitude star Sigma Aquarii through mid-September, making a great guide to find the planet…

Aug 29 — The orbit of Triton on the evening of August 29th, superimposed on a one arc minute field of view. Created using Starry Night Software.

Still not enough of a challenge? Try tracking down Neptune’s large moon, Triton. Orbiting the planet in a retrograde path once every 5.9 days, Triton is within reach of a large backyard scope at magnitude +14. Triton never strays more than 15” from the disk of Neptune, but opposition is a great time to cross this curious moon off of your observing life list. Neptune has 14 moons at last count.

And speaking of Triton, NASA recently released a new map of the moon. We’ve only gotten one good look at Triton, Neptune, and its retinue of moons back in 1989 when Voyager 2 conducted the only flyby of the planet to date. Will Pluto turn out to be Triton’s twin when New Horizons completes its historic flyby next summer?

The Moon also passes 4.3 degrees north of Neptune on September 8th on its way to “Supermoon 3 of 3” for 2014 on the night of September 8^th/9th. Fun fact: a cycle of occultations of Neptune by the Moon commences on June 2016.

When will we explore Neptune once more? Will a dedicated “Neptune orbiter” ever make its way to the planet in our lifetimes? All fun things to ponder as you check out the first planet discovered using scientific reasoning this weekend.

August 25, 2014December 23, 2015 by David Dickinson

Astronomy History and Future Come Together at the South Carolina State Museum

Seeking out science and astronomy in South Carolina? You’re in luck, as we’re pleased to report the South Carolina State Museum’s brand-spanking new planetarium and astronomical observatory opened to the public earlier this month. Part of a 75,000 square foot expansion project dubbed Windows to New Worlds, the renovation puts the museum on the cutting edge of STEM education and public outreach. And not only does the new expansion include one of the largest planetariums in the southeastern U.S., but it also features the only 4D theater in the state of South Carolina. The observatory, planetarium and brand new exhibits present a fascinating blend of the grandeur of astronomical history and modern technology.

“What we have built represents a quantum leap forward for South Carolina in the areas of cultural tourism, recreation and especially education,” said executive director of the South Carolina State Museum Willie Calloway in a recent press release. “Our new facility is building opportunity — opportunity for students to thrive, opportunity for our economy to grow and opportunity for our guests to be entertained in new ways.”

We first visited the South Carolina State Museum in 2012 when plans for the planetarium and observatory were just starting to come together. The large Alvan Clark refractor now in the observatory was on display in the main museum, but much of the telescopes in the museum’s collection of antique instruments and gear were yet to be seen by the public.

We firmly believe that a telescope out under the night sky is a happy telescope, and it’s great to see the old 12 3/8” Alvan Clark refractor in action once again!

The expansion also includes a new display for the Robert Ariail collection, a fascinating assortment of astronomical instruments dating back to 1730. A highlight of the display is a 5.6-inch refractor designed by American optician and telescope maker Henry Fitz in 1849 for Erskine College. This stands as the oldest surviving American manufactured telescope known. The Robert Ariail collection is one of the largest collections of antique refracting telescopes in the world. We were amazed at the array of old solar projectors and filters, including some that we could not immediately identify.

Just how did some of those astronomers of yore observe the Sun other than projection? In some cases, they used smoked glass… but often, we learned at our behind the scenes tour at the South Carolina State museum in Columbia that they observed the Sun through an adapter filled with dark oil. No, don’t try this inconsistent and incredibly dangerous method of solar observing at home! We also noted that several of the solar filters were cracked, which no doubt occurred while they were in use.

The Planetarium: The new planetarium is known officially as the BlueCross/BlueShield of South Carolina Planetarium, and the new 55-foot diameter digital dome seats 145 and is now running shows that cover art, science, history and — of course — astronomy. Laser light shows set to a modern rock soundtrack —cue pink Floyd’s Dark Side of the Moon, sides one and two — are also planned. And don’t miss the NASA gallery in the lobby to the planetarium which features artifacts from South Carolina hometown astronauts Frank Culbertson, Ron McNair, Charles Duke and Charles Bolden.

The Observatory: The Boeing Astronomical Observatory is now open for business and features the aforementioned Alvan Clark 12 3/8-inch refracting telescope. Built in 1926, this grand old refractor bespeaks of a bygone era when astronomers actually looked through telescopes, pipe in hand, atop some distant windswept mountain. Squint hard, and maybe you’ll spy a canal festooned Mars… OK, maybe that’s a stretch, but it’s amazing to look through one of these grand old instruments, in person. And the observatory is the only one of its kind in the United States (and perhaps the world) that will offer modern remote access to an antique telescope to classroom students.

The observatory also includes a classroom, outdoor viewing terrace, and a modern state-of-the-art computer control system that those old “astronomers of yore” only wish that they’d had, especially when they had to manually crank up the mechanical counterweights on their clock drives!

Not only is the observatory open for night viewing — and just in time for the upcoming October 8^th total lunar eclipse — but they’re also open to the public for daily solar observing sessions as well. And we promise they’re utilizing the very latest in solar safety technology… no overheating oil-filled filters allowed!

The 2017 total solar eclipse and the future: But there’s another reason to visit Columbia South Carolina about three years hence: the city and the South Carolina State Museum will once again be the center of astronomical action in less than three years time, when a total solar eclipse crosses the state from the northwest to the southeast on august 21^st, 2017. Towns across the United States are already preparing for this celestial spectacle, and Columbia is one of the largest cities along its path. It promises to be a great show!

Don’t miss these exciting goings on in Columbia, South Carolina… the new planetarium and observatory is truly “brighter than ever” and out of this world!

Follow the South Carolina State Museum as @SCStateMuseum and the hashtags #scsm and #BrighterThanEver.

August 20, 2014December 23, 2015 by David Dickinson

Remembering the “World War I Eclipse”

The paths of total solar eclipses care not for political borders or conflicts, often crossing over war-torn lands.

Such was the case a century ago this week on August 21^st, 1914 when a total solar eclipse crossed over Eastern Europe shortly after the outbreak of World War I.

Known as the “War to End All Wars,” — which, of course, it didn’t — World War I would introduce humanity to the horrors of modern warfare, including the introduction of armored tanks, aerial bombing and poison gas. And then there was the terror of trench warfare, with Allied and Central Powers slugging it out for years with little gain.

But ironically, the same early 20^th century science that was hard at work producing mustard gas and a better machine gun was also pushing back the bounds of astronomy. Einstein’s Annus Mirabilis or “miracle year” occurred less than a decade earlier on 1905. And just a decade later in 1924, Edwin Hubble would expand our universe a million-fold with the revelation that “spiral nebulae” were in fact, island universes or galaxies in their own right.

Indeed, it’s tough to imagine that many of these discoveries are less than a century in our past. It was against this backdrop that the total solar eclipse of August 21^st, 1914 crossed the eastern European front embroiled in conflict.

Solar eclipses have graced the field of battle before. An annular solar eclipse occurred during the Battle of Isandlwana in 1879 during the Zulu Wars, and a total solar eclipse in 585 B.C. during the Battle of Thales actually stopped the fighting between the Lydians and the Medes.

A photograph of an “eclipse camp” in the Crimea in 1914. Credit: University of Cambridge DSpace.

But unfortunately, no celestial spectacle, however grand, would save Europe from the conflagration war. In fact, several British eclipse expeditions were already en route to parts of Russia, the Baltic, and Crimea when the war broke out less than two months prior to the eclipse with the assassination of Archduke Ferdinand on June 28^th, 1914. Teams arrived to a Russia already mobilized for war, and Britain followed suit on August 4^th, 1914 and entered the war when Germany invaded Belgium.

You can see an ominous depiction of the path of totality from a newspaper of the day, provided from the collection of Michael Zeiler:

1914_August_22_TSE_The_Graphic_1 — An illustration of the 1914 total solar eclipse “scorching” a war-ravaged Europe. Credit: From the collection of Michael Zeiler. Used with permission.

Note that the graphic depicts a Europe aflame and adds in the foreboding description of Omen faustum, inferring that the eclipse might be an “auspicious omen…” eclipses have never shaken their superstitious trappings in the eyes of man, which persists even with today’s fears of a “Blood Moon.”

A race was also afoot against the wartime backdrop to get an expedition to a solar eclipse to prove or disprove Einstein’s newly minted theory of general relativity. One testable prediction of this theory is that gravity bends light, and astronomers soon realized that the best time to catch this in action would be to measure the position of a star near the limb of the Sun — the most massive light bending object in our solar system — during a total solar eclipse. The advent of World War I would scrub attempts to observe this effect during the 1914 and 1916 eclipses over Europe.

An expedition led by astronomer Arthur Eddington to observe an eclipse from the island of Principe off of the western coast of Africa in 1919 declared success in observing this tiny deflection, measuring in less than two seconds of arc. And it was thus that a British expedition vindicated a German physicist in the aftermath of the most destructive war up to that date.

The total solar eclipse of August 21^st 1914 was a member of saros cycle 124, and was eclipse number 49 of 73 in that particular series. Eclipses in the same saros come back around to nearly the same circumstances once every triple saros period of 3 times 18 years and 11.3 days, or about every 54+ years, and there was an eclipse with similar circumstances slightly east of the 1914 eclipse in 1968 — the last total eclipse of saros 124 — and a partial eclipse from the same saros will occur again on October 25^th, 2022.

All historical evidence we’ve been able to track down suggests that observers that did make it into the path of totality were clouded out at show time, or at very least, no images of the August 21^st 1914 eclipse exist today. Can any astute reader prove us wrong? We’d love to see some images of this historical eclipse unearthed!

A simulation of the total solar eclipse of August 21st 1914 as seen from Latvia. Created using Starry Night Education software.

And, as with all things eclipse related, the biggest question is always: when’s the next one? Well, we’ve got another of total lunar eclipse coming right up on October 8^th, 2014, again favoring North America. The next total solar eclipse occurs on March 20^th, 2015 but is only visible along a path covering the Faroe and Svalbard Islands, with a path crossing the Norwegian Sea.

But, by happy coincidence, we’re also only now three years out this week from the total solar eclipse of August 21^st, 2017 that spans the contiguous “Lower 48” of the United States. The shadow of the Moon will race from the northwest and make landfall off of the Pacific coast of Oregon before reaching a maximum duration for totality at 2 minutes and 40 seconds across Missouri, southern Illinois and Kentucky and will then head towards the southeastern U.S. to depart land off of the coast of South Carolina. Millions will witness this event, and it will be the first total solar eclipse for many. A total solar eclipse hasn’t crossed the contiguous United States since 1979, so you could say that we’re “due”!

Already, towns in Kentucky to Nebraska have laid plans to host this event. The eclipse occurs towards the afternoon for residents of the eastern U.S., which typically sees afternoon thunderstorms popping up in the sultry August summer heat. Eclipse cartographer Michael Zeiler states that the best strategy for eclipse chasers three years hence is to “go west, young man…”

It’s fascinating to ponder tales of eclipses past, present, and future and the role that they play in human history… where will you be on August 21^st, 2017?

– Check out Michael Zeiler’s new site, GreatAmericanEclipse.com

– Eclipses pop up in science fiction on occasion as well… check out our history spanning eclipse tale Exeligmos.

August 13, 2014December 23, 2015 by David Dickinson

A Spectacular Dawn Conjunction of Venus and Jupiter Set For August 18th

The last dawn pairing of Venus, Jupiter and the crescent Moon in the dawn sky in 2012... this month's will be much tighter! Credit: Tavi Greiner.

“What are those two bright stars in the morning sky?”

About once a year we can be assured that we’ll start fielding inquires to this effect, as the third and fourth brightest natural objects in the sky once again meet up.

We’re talking about a conjunction of the planets Jupiter and Venus. Venus has been dominating the dawn sky for 2014, and Jupiter is fresh off of solar conjunction on the far side of the Sun on July 24th and is currently racing up to greet it.

We just caught sight of Jupiter for the first time for this apparition yesterday from our campsite on F.E. Warren Air Force Base in Cheyenne, Wyoming. We’d just wrapped up an early vigil for Perseid meteors and scrambled to shoot a quick sequence of the supermoon setting behind a distant wind farm. Jupiter was an easy catch, first with binoculars, and then the naked eye, using brilliant Venus as a guide post.

The view looking eastward at dawn on August 18th, including a five degree telrad (red circles) and a one degree telescopic field of view (inset). Created using Stellarium.

And Jupiter will become more prominent as the week progresses, climaxing with a fine conjunction of the pair on Monday, August 18^th. This will be the closest planet versus planet conjunction for 2014. At their closest — around 4:00 Universal Time or midnight Eastern Daylight Saving Time — Venus and Jupiter will stand only 11.9’ apart, less than half the diameter of a Full Moon. This will make the pair an “easy squeeze” into the same telescopic field of view at low power. Venus will shine at magnitude -3.9, while Jupiter is currently about 2 magnitudes or 6.3 times fainter at magnitude -1.8. In fact, Jupiter shines about as bright as another famous star just emerging into the dawn sky, Sirius. Such a dawn sighting is known as a heliacal rising, and the first recovery of Sirius in the dawn heralded the flooding of the Nile for the ancient Egyptians and the start what we now term the Dog Days of Summer.

To the naked eye, enormous Jupiter will appear to be the “moon” that Venus never had next weekend. The spurious and legendary Neith reported by astronomers of yore lives! You can imagine the view of the Earth and our large Moon as a would-be Venusian astronomer stares back at us (you’d have to get up above those sulfuric acid clouds, of course!)

Said conjunction is only a product of our Earthly vantage point. Venus currently exhibits a waxing gibbous disk 10” across — three times smaller than Jupiter — but Venus is also four times closer to Earth at 1.61 astronomical units distant. And from Jupiter’s vantage point, you’d see a splendid conjunction of Venus and the Earth, albeit only three degrees from the Sun:

How often do the two brightest planets in the sky meet up? Well, Jupiter reaches the same solar longitude (say, returns back to opposition again) about once every 13 months. Venus, however, never strays more than 47.1 degrees elongation from the Sun and can thus always be found in either the dawn or dusk sky. This means that Jupiter pairs up with Venus roughly about once a year:

A list of Venus and Jupiter conjunctions, including angular separation and elongations (west=dawn, east=dusk) from now until 2020. Created by author.

Note that next year and 2019 offer up two pairings of Jupiter and Venus, while 2018 lacks even one. And the conjunction on August 27^th, 2016 is only 4’ apart! And yes, Venus can indeed occult Jupiter, although that hasn’t happened since 1818 and won’t be seen again from Earth until – mark your calendars – November 22^nd, 2065, though only a scant eight degrees from the Sun. Hey, maybe SOHO’s solar observing successor will be on duty by then…

Venus has been the culprit in many UFO sightings, as pilots have been known to chase after it and air traffic controllers have made furtive attempts to hail it over the years. And astronomy can indeed save lives when it comes to conjunctions: in fact, last year’s close pairing of Jupiter and Venus in the dusk sky nearly sparked an international incident, when Indian Army sentries along the Himalayan border with China mistook the pair for Chinese spy drones. Luckily, Indian astronomers identified the conjunction before shots were exchanged!

Earth strikes back... — Earth strikes back… firing a 5mw green laser at the 2013 conjunction of Jupiter and Venus. Photo by author.

Next week’s conjunction also occurs against the backdrop of Messier 44/Praesepe, also known as the “Beehive cluster”. It’ll be difficult to catch sight of M44, however, because the entire “tri-conjunction” sits only 18 degrees from the Sun in the dawn sky. Binocs or a low power field of view might tease out the distant cluster from behind the planetary pair.

And to top it off, the waning crescent Moon joins the group on the mornings of August 23^rd and 24^th, passing about five degrees distant. Photo op! Can you follow Venus up into the daytime sky, using the Moon as a guide? How about Jupiter? Be sure to block that blinding Sun behind a hill or building while making this attempt.

The addition of the Moon will provide the opportunity to catch a skewed “emoticon” conjunction. A rare smiley face “:)” conjunction occurred in 2009, and another tight skewed tri-conjunction is in the offering for 2056. While many national flags incorporate examples of close pairings of Venus and the crescent Moon, we feel at least one should include a “smiley face” conjunction, if for no other reason than to highlight the irony of the cosmos.

A challenge: can you catch a time exposure of the International Space Station passing Venus and Jupiter? You might at least pull off a “:/” emoticon image!

Don’t miss the astronomical action unfolding in a dawn sky near you over the coming weeks. And be sure to spread the word: astronomical knowledge may just well avert a global catastrophe. The fate of the free world lies in the hands of amateur astronomers!

August 4, 2014December 23, 2015 by David Dickinson

Get Set For Super (Duper?) Moon 2 of 3 For 2014

The July 2014 Supermoon rising over the University of Texas at Austin Tower. Credit: Mark Ezell, used with permission.

You could be forgiven for thinking this summer that the “supermoon” is now a monthly occurrence. But this coming weekend’s Full Moon is indeed (we swear) the closest to Earth for 2014.

What’s going on here? Well, as we wrote one synodic month ago — the time it takes for the Moon to return to the same phase at 29.5 days — we’re currently in a cycle of supermoons this summer. That is, a supermoon as reckoned as when the Full Moon falls within 24 hours of perigee, a much handier definition than the nebulous “falls within 90% of its orbit” proposed and popularized by astrologers.

The supermoons for 2014 fall on July 13th, August 10th and September 8th respectively. You could say that this weekend’s supermoon is act two in a three act movement, a sort of Empire Strikes Back to last month’s A New Hope.

Now for the specifics: Full Moon this weekend occurs on August 10^th at 18:10 Universal Time (UT) or 2:10 PM EDT. The Moon will reach perigee or its closest point to the Earth at 17:44 UT/1:44 PM EDT just 26 minutes prior to Full, at 55.96 Earth radii distant or 356,896 kilometres away. This is just under 500 kilometres shy of the closest perigee that can occur at 356,400 kilometres distant. Perigee was closer to Full phase time-wise last year on June 23^rd, 2013, but this value won’t be topped or tied again until November 25^th, 2034. The Moon will be at the zenith and closest to the surface of the Earth at the moment it passes Full over the mid-Indian Ocean on Sunday evening nearing local midnight.

Now for a reality check: The August lunar perigee only beats out the January 1^st approach of the Moon for the closest of 2014 by a scant 25 kilometres. Perigees routinely happen whether the Moon is Full or not, and they occur once every anomalistic month, which is the average span from perigee-to-perigee at 27.6 days. This difference between the anomalistic and synodic period causes the coincidence that is the supermoon to precess forward about a month a year. You can see our list of supermoon seasons out until 2020 here.

And don’t forget, the Moon actually approaches you to the tune of about half of the radius of the Earth while it rises to the zenith, only to recede again as it sinks back down to the horizon. The rising Full Moon on the horizon only appears larger mainly due to an illusion known as the Ponzo Effect.

The apparent size of the Moon varies about 14% in angular diameter from 29.3′ (known as an apogee “mini-Moon”) to 34.1′ at its most perigee “super-size” as seen from the Earth.

Astronomers prefer the use of the term Perigee Full Moon, but the supermoon meme has taken on a cyber-life of its own. Of course, we’ve gone on record before and stated that we prefer the more archaic term Proxigean Moon, but the supermoon seems here to stay.

And as with many Full Moon myths, this week’s supermoon will be implicated in everything from earthquakes to lost car keys to other terrestrial woes, though of course no such links exist. Coworkers/family members/strangers on Twitter will once again insist it was “the biggest ever,” and claim it took up “half the sky” as they unwittingly take part in an impromptu psychological perception test.

Fun fact: you could ring local the horizon with 633 supermoons!

And of course, many a website will recycle their supermoon posts, though of course not here at Universe Today, as we bake our science fresh daily.

So what can you expect? Well, a perigee Full Moon can make for higher than usual tides. New York City residents had the bad fortune of a Full Moon tidal surge in 2012 when Hurricane Sandy made landfall. Though there doesn’t seem to be a chance for a repeat of such an occurrence in 2014 in the Atlantic, super-typhoon Halong is churning towards the Japanese coastline for landfall this weekend…

The rising Waxing Gibbous Moon on the evening of August 9th. Credit: Stellarium.

Observationally, Full Moon is actually a lousy time for astronomical observations, causing many a deep sky astrophotographer to instead stay home and visit the family, while lurking astrophotography forums and debunking YouTube UFO videos.

Pro-tip: want your supermoon photo/video to go viral? Shoot the rising Moon just the evening prior when it’s waxing gibbous but nearly Full. Not only will it be more likely to be picked up while everyone is focused on supermoon lunacy, but you’ll also have the added bonus of catching the Moon silhouetted against a low-contrast dusk sky. We have a pre-supermoon rising video from a few years back that still trends with each synodic period!

Well, that’s it ‘til September, when it’ll be The Return (Revenge?) of the Supermoon. Be sure to send those pics in to Universe Today’s Flickr forum, you just might make the supermoon roundup!

July 28, 2014December 23, 2015 by David Dickinson

When Good Meteor Showers Go Bad: Prospects for the 2014 Perseids

It’s that time of year again, when the most famous of all meteor showers puts on its best display.

Why are the Perseids such an all ‘round favorite of sky watchers? Well, while it’s true that other annual meteor showers such as the Quadrantids and Geminids can exceed the Perseids in maximum output, the Perseids do have a few key things going for them. First, the shower happens in mid-August, which finds many northern hemisphere residents camping out under warm, dark skies prior to the start of the new school year. And second, unlike showers such as the elusive Quads which peak over just a few hours, the Perseids enjoy a broad span of enhanced activity, often covering a week or more.

The orientation of the orbital path of Comet 109P/Swift-Tuttle and the position of the Earth on August 12th. Credit: JPL-Horizons.

These are all good reasons to start watching for Perseids now. Here’s the low down on the Perseid meteors for 2014:

The History: The Perseids are sometimes referred to as “The Tears of Saint Lawrence,” who was martyred right around the same date on August 10^th, 258 A.D. The source of the shower is comet 109P Swift-Tuttle, which was first identified as such by Schiaparelli in 1866. The comet itself visited the inner solar system again recently in 1992 on its 120 year orbit about the Sun, and rates were enhanced throughout the 1990s.

A 2013 Perseid pierces the plane of the Milky Way. Credit: Stephen Rahn.

Unlike most showers, the Perseids have a very broad peak, and observers and automated networks such as UKMON and NASA’s All Sky Camera sites have already begun to catch activity starting in late July.

A pair of early 2014 Perseids recently captured by UKMON’s Wilcot station. Credit: The UK-MON network.

In recent years, the rates for the Perseids have been lowering a bit but are still enhanced, with ZHRs at 91(2010), 58(2011), 122(2012), and 109(2013). It’s also worth noting that the Perseids typically exhibit a twin peak maximum within a 24 hour span. The International Meteor Organization maintains an excellent page for quick look data to check out what observers worldwide are currently seeing. The IMO also encourages observers worldwide to submit meteor counts by location. Note that the phase of the Moon was near Full in 2011, with observing circumstances very similar to 2014.

The Prospects for 2014: Unfortunately, the 2014 Perseid meteors have a major strike going against them this year: the Moon will be at waning gibbous during its peak and just two days past Full illumination. This will make for short exposure times and light polluted skies. There are, however, some observational strategies that you can use to combat this: one is to place a large building or hill between yourself and the Moon while you observe — another is to start your morning vigil a few days early, before the Moon reaches Full. The expected Zenithal Hourly Rate for 2014 is predicted to hover around 90 and arrive around 00:15 to 2:00 UT on August 13^th favoring Europe, Africa and the Middle East.

The orientation of Earth’s shadow during the projected peak of the Perseids on August 13th at 00:15 Universal Time. The positions where the Sun, Moon, and radiant of the Perseids are directly overhead are also noted. Created by Author.

The Radiant: It’s strange but true: meteor shower radiants wander slightly across the sky during weeks surrounding peak activity, due mostly to the motion of the Earth around the Sun. Because of this, the radiant of the Perseids is not actually in the constellation Perseus on the date that it peaks! At its maximum, the radiant actually sits juuusst north of the constellation that it’s named for on the border of Camelopardalis and Cassiopeia. This is a great pedantic point to bring up with your friends on your August meteor vigil… they’ll sure be glad that you pointed this out to ’em and hopefully, invite you back for next year’s Perseid watch.

The actual position of the radiant sits at 3 Hours 04’ Right Ascension and +58 degrees north declination.

The movement of the radiant of the Perseids. The sky is simulated for latitude 30 degrees north at 2:00 AM local on August 13th. Credit: Starry Night Education software.

Meteor-speak: Don’t know your antihelion from a zenithal hourly rate? We wrote a whole glossary that’ll have you talking meteors like a pro for Adrian West’s outstanding Meteorwatch site a few years back. Just remember, the crucial “ZHR” of a shower that is often quoted is an ideal extrapolated rate… light pollution, the true position of the radiant, observer fatigue and limited field of view all conspire to cause you to see less than this predicted maximum. The universe and its meteor showers are indeed a harsh mistress!

Observing: But don’t let this put you off. As Wayne Gretsky said, “You miss 100% of the shots that you don’t take,” and the same is true with meteor observing: you’re sure to see exactly zero if you don’t observe at all. Some of my most memorable fireball sightings over the years have been Perseids. And remember, the best time to watch for meteors is after local midnight, as the Earth is turned forward into the meteor stream. Remember, the car windshield (Earth) gets the bugs (meteors) moving down the summer highway…

Good luck, and let us know of those tales of Perseid hunting and send those meteor pics in to Universe Today!

July 25, 2014December 23, 2015 by David Dickinson

Having Fun with the Equation of Time

An analemma of the Sun, taken from Budapest, Hungary over a one year span. (Courtesy of György Soponyai, used with permission).

If you’re like us, you might’ve looked at a globe of the Earth in elementary school long before the days of Google Earth and wondered just what that strange looking figure eight thing on its side was.

Chances are, your teacher had no idea either, and you got an answer such as “it’s a calendar, kid” based on the months of the year marking its border.

In a vague sense, this answer is correct… sort of. That funky figure eight is what’s known as an analemma, and it traces out the course of the Sun in the sky through the year as measured from a daily point fixed in apparent solar time.

Analemma (Wikimedia Commons image). — Ye ole analemma… perpetually lost in the South Pacific? (Wikimedia Commons image).

But try explaining that one to your 3^rd grade teacher. Turns out, measuring the passage of time isn’t as straight forward as you’d think. Our modern day clock and calendar is a sort of compromise, a method of marking the passage of time in a continuing battle to stay in sync with the heavens.

For most of history, the daily passage of time was denoted by the Sun. Solar Noon occurs when the Sun stands at its highest elevation (also known as its altitude) above the local horizon when it transits the north-south meridian. The trouble is, the passage apparent solar time doesn’t exactly match what we call solar mean time, or the 24 hour rotation of the Earth. In fact, this discrepancy can add up to as much as more than 16 minutes ahead of solar noon in late October and November and over 12 minutes behind it in February. This is worth bringing up this week because this factor, known as “The Equation of Time” — think “equation” in the sense that sundial owners must factor it in to make solar mean and apparent time “equal” — reaches its shallow minimum for 2014 this Saturday at 7:00 UT/3:00 AM EDT with a value of -6.54 minutes.

The solar analemma as plotted from the latitude of the Greenwich Observatory in England. (Wikimedia Commons/PAR/JPL Horizons).

So, what gives? Why won’t the pesky universe stay in sync?

Well, the discrepancy arises from two factors: the eccentricity of the Earth’s orbit, or how much it deviates from circular and the obliquity of the ecliptic to the celestial equator, think the tilt of Earth’s axis. Of the two, obliquity is the major factor, with eccentricity playing a minor but measurable role. And remember, we move slightly faster in our orbit in January near perihelion as per Kepler’s Laws of planetary motion than at aphelion, which occurred earlier this month , though be careful not to confuse the term “faster” with “sun fast.”

This means that were the Earth to orbit the Sun in a perfect circle with its poles perpendicular to its orbit, apparent and mean time would essentially stay in sync. Of course, no known planet has such a perfect alignment scenario, and other worlds do indeed host alien analemmas (analemmae?) of their own.

It’s also interesting to note that the two each major and minor minima of the Equation of Time roughly coincide with the four cross quarter tie in days of the year (marked by Groundhog’s Day, May Day, Lammas Day and Halloween, respectively) while the zero value points fall within a few weeks of the equinoxes and solstices.

A graph showing the flucuation of the value of the Equation of Time throughout the callendar year. (Created by the author). — A graph showing the fluctuation of the value of the Equation of Time (with minutes on the vertical axis) throughout the calendar year. (Created by the author).

In the current epoch, the deep minimum falls on February 21^st, while the highest maximum falls on November 3^rd on non-leap years. The four zero value dates are April 15^th, June 13^th, September 1^st and December 25^th respectively. The exact timing of these also slip to the tune of about a second a year, but of course, most sundials lack this sort of precision.

A "globe sundial" on the University of North Dakota at grand Forks campus. (Photo by author). — A “globe sundial” on the University of North Dakota at Grand Forks campus. (Photo by author).

So, why should we care about the Equation of Time in the modern atomic clock age? It is true that there have been calls over the past few years to “abolish the leap second” and go off of the astronomical time standard entirely… if this ever does come to pass, some future Pope Gregory will have to institute a “leap hour” circa 10,000 A.D. or so to stop the Sun from rising at 2 AM. But some modern day Sun tracking devices (think heliostats or solar panels) do in fact use mechanical timers and must take the equation of time into account to maximize effectiveness.

Impatient? You can plot your very own simulated analemma using a desktop planetarium program. (Credit: Starry Night Education software).

Want to see the Equation of Time in action? You can make your own analemma simply by photographing the position of the Sun at the same time each day. Just remember to account for the shift on and off of Daylight Saving if you live in an area that observes the archaic practice, residents of Arizona need not to take heed. Otherwise, you’ll end up with a “split analemma…” Wintertime near the December Solstice is the best time to start this project, as the Sun is at its lowest noonday culmination and this will assure that your very own personal analemma won’t fall below the local horizon.

Farther afield, the effects of the Precession of the Equinoxes will also tweak the dates of the Equation of Time values a bit. Live out a full 72 year life span, and the equinoctial points will have drifted along the ecliptic by about one degree, twice the diameter of the Full Moon. Incidentally, the failure to take Precession into account is yet another spectacular fail of modern astrology: most “houses” or “signs” have drifted in the past millennia to the point where most “Leos” are in fact “Cancers!”

Such is the challenges and vagaries of modern day astronomical time-keeping. Let us know of your tales of tragedy and triumph as you hunt down the elusive analemma.

July 18, 2014December 23, 2015 by David Dickinson

Observing Challenge: 6 White Dwarf Stars to See in Your Backyard Telescope

Dazzlimg Sirius, with its white dwarf companion to the lower left. Credit: NASA, ESA, H. Bond (STScI) and M. Barstow (University of Leicester).

Looking for something off beat to observe? Some examples of curious astronomical objects lie within the reach of the dedicated amateur armed with a moderate-sized backyard telescope. With a little skill and persistence, you just might be able to track down a white dwarf star. Unlike splashy nebulae or globular clusters, a white dwarf star will just appear as a speck, a tiny dot in the field of view of your telescope’s eyepiece. But just as in the case of observing other exotic objects such as red giants and quasars, part of the thrill of tracking down these astrophysical beasties is in knowing just what it is that you’re seeing. Heck, many amateur astronomers fail to realize that any white dwarf stars are within range of their instruments and have never tracked one down.

The astrophysical nature of white dwarf stars was first uncovered in the early 20^th century. Most of the early white dwarf stars discovered were companions in binary star systems and this allowed astronomers to gauge their mass by following the orbital motion of such pairs over time. Soon, astronomers realized that they were looking at something peculiar, a new type of compact but massive stellar object that stubbornly refused to be pigeon-holed along the main sequence of the freshly conceived Hertzsprung-Russell diagram.

Today, we know that white dwarf stars are the remnants of stars which have long since passed the Red Giant stage. We say that a white dwarf is a degenerate star, and no, this not a commentary on its moral state. The Chandrasekhar limit gives us an upper limit in size for a white dwarf at about 1.4 solar masses, beyond which electron degeneracy pressure can no longer act against the inward pull of gravity. Our Sun will one day become a white dwarf, over 6 billion years from now. Think of cramming the mass of our star into the volume of the Earth and you have some idea just how dense a white dwarf is: a cubic centimetre of white dwarf weighs 250 about tons, and two cup fulls of white dwarf would weigh more than a Nimitz-class aircraft carrier.

Think of a white dwarf as a cooling ember of a star long past its hydrogen fusing prime. And white dwarfs will cool down to infrared radiating black dwarfs over trillions of years, far longer than the present 13.7 billion year age of the universe. In fact, the age of white dwarfs currently observed is one on the underpinning tenets of modern Big Bang cosmology.

All amazing stuff. In any event, here is a baker’s half dozen of white dwarf stars that you can find with a telescope tonight. A more extensive list of the nearest white dwarfs to the Earth can be found on Sol Station.

The orbit of Sirius B. Wikimedia Commons image in the Public Domain.

Sirius B: This is the nearest white dwarf to the Earth at 8.6 light years distant. Shining at magnitude +8.5, Sirius B would be a cinch to see, if only dazzling Sirius A — the brightest star in our sky at magnitude -1.5 — were not nearby. Sirius B orbits its primary once every 50 years and will reach a maximum separation of 11.5” from its primary in 2025, a prime time to cross it off of your life list in the coming decade. Blocking the primary just out of the field of view, or using an occulting bar eyepiece is key to finding Sirius B.

Sirius B was discovered by American telescope maker Alvan Graham Clark in 1862. The Dogon people of Mali also have some curious myths surrounding the star Sirius.

Constellation: Canis Major

Right Ascension: 6 Hours 45’

Declination: -16° 43’

The apparent orbit of Procyon B through 2039. Graphic created by the author.

Procyon B: Located 11.5 light years distant, Procyon B was discovered in 1896 by John Martin Schaeberle from the Lick observatory. Shining at magnitude +10.7, the chief difficultly with spotting this white dwarf, as with Sirius B, is that it has a companion about 10 magnitudes – that’s 10,000 times brighter – nearby just 4.3” away.

Constellation: Canis Minor

Right Ascension: 7 hours 39’

Declination: +5 13’

-LP145-141: Also known as GJ 440, LP145-141 is one of the best southern hemisphere white dwarf stars on the list. LP145-141 is a solitary white dwarf shining at magnitude +11.5. Located 15 light years distant, LP145-141 is thought to be a member of the nearby Wolf 219 Moving Group of stars.

Constellation: Musca

Right Ascension: 11 Hours 46’

Declination: -64° 50’

The location of Van Maanen’s Star in the constellation Pisces. Credit: Stellarium

-Van Maanen’s Star: Shining at magnitude +12.4 and located 14.1 light years distant, Van Maanen’s star is the closest solitary white dwarf to Earth and the best example of a white dwarf for small telescopes. Discovered by Ariaan van Maanen in 1917, Van Maanen’s Star also has a very high proper motion of 3” per year.

Constellation: Pisces

Right Ascension: 00 Hours 49’

Declination: 05° 23’

The 40 Omicron Eridani system. Image by Author

-40 Omicron Eridani B: This is a great one to track down. The triple system of 40 Omicron Eridani b contains a fine example of a red and white dwarf orbiting a main sequence star. Located 16.5 light years distant and shining at magnitude +9.5, Omicron Eridani was the first white dwarf star discovered in 1783 by Sir William Herschel, although its true nature wasn’t deduced until 1910. Omicron Eridani B is currently 82” from its primary, an easy split.

Constellation: Eridanus

Right Ascension: 4 Hours 15’

Declination: 7° 39’

-Stein 2051: Rounding off the list and located just over 18 light years distant, Stein 2051 is another example of a red dwarf/white dwarf pair. Stein 2051 b shines at a similar brightest to Van Maanen’s star at magnitude +12.4.

Constellation: Camelopardalis

Right Ascension: 04 Hours 31’

Declination: +58° 59’

Let us know about your trials and triumphs in hunting down these fascinating objects!