Don't fear the moonlight... Credit and copyright: John Chumack.
Quick… what’s the only major meteor shower named after a defunct constellation? If you said the January Quadrantids, you’d be correct, as this often elusive but abrupt meteor shower is set to peak this coming weekend early in 2015.
And we do mean early, as in the night of January 3rd going into the morning of January 4th. This is a bonus, as early January means long dark nights for northern hemisphere observers. But the 2015 Quadrantids also has two strikes going against them however: first, the Moon reaches Full just a day later on January 5th, and second, January also means higher than average prospects for cloud cover (and of course, frigid temps!) for North American observers.
The rising radiant of the Quads on the morning of January 4th at 3AM local. Note that the Moon and Jupiter are on the scene as well. Created using Starry Night Education software.
Don’t despair, however. In meteor shower observing as in hockey, you miss 100% of the shots that you don’t take.
Sorry for the sports analogy. The radiant for the Quadrantids is located in the modern day constellation of Draco near the Hercules-Boötes border at a right ascension 15 hours, 18 minutes and declination +49.5 degrees north. This puts it very near the +3.3 magnitude star Iota Draconis (Edasich).
The orientation of the Earth’s shadow at the predicted peak of the Quads on January 4th, 2:00 UT. Credit: Orbitron.
In 2015, bets are on for the Quadrantids to peak centered on 2:00 UT January 4th (9:00 PM EST on the 3rd), favoring northern Europe pre-dawn. The duration for the Quadrantids is short lived, with an elevated rate approaching 100 per hour lasting only six hours in duration. Keep in mind, of course, that it’ll be worth starting your vigil on Saturday morning January 3rd in the event that the “Quads” kick off early! I definitely wouldn’t pass up on an early clear morning on the 3rd, just in case skies are overcast on the morning of the 4th…
Due to their high northern radiant, the Quadrantids are best from high northern latitudes and virtually invisible down south of the equator. Keep in mind that several other meteor showers are active in early January, and you may just spy a lingering late season Geminid or Ursid ‘photobomber’ as well among the background sporadics.
Moonset on the morning of the 4th occurs around 6 AM local, giving observers a slim one hour moonless window as dawn approaches. Blocking the Moon out behind a building or hill when selecting your observing site will aid you in your Quadrantid quest.
The approximate realm of the “Mural Quadrant” overlaid on modern day constellations. Credit Stellarium.
Antonio Brucalassi made the first historical reference to the Quadrantids, noting that “the atmosphere was traversed by… falling stars” on the morning of January 2nd, 1825. It’s interesting to note that the modern day peak for the Quads has now drifted a few days to the fourth, due mostly to the leap year-induced vagaries of our Gregorian calendar. The early January meteor shower was noted throughout the 19th century, and managed to grab its name from the trendy 19th century constellation of Quadrans Muralis, or the Mural Quadrant. Hey, we’re lucky that other also-rans, such as Lumbricus the ‘Earthworm’ and Officina Typograhica the ‘Printing Office’ fell to the wayside when the International Astronomical Union formalized the modern 88 constellations in 1922. Today, we know that the Quadrantids come from 2003 EH1, which is thought to be an extinct comet now trapped in the inner solar system on a high inclination, 5.5 year orbit. Could 2003 EH1 be related to the Great Comet of 1490, as some suggest? The enigmatic object reached perihelion in March of 2014, another plus in the positive column for the 2015 Quads.
What the heck is a Mural Quadrant? Like everything he did, Tycho Brahe super-sized his quadrant, depicted here. Credit: Wikimedia Commons.
Previous years for the Quadrantids have yielded the following Zenithal Hourly Rate (ZHR) maximums as per the International Meteor Organization:
2011= 90
2012= 83
2013= 137
2014= +200
The Quadrantid meteor stream has certainly undergone alterations over the years as a result of encounters with the planet Jupiter, and researchers have suggested that the shower may go the way of the 19th century Andromedids and become extinct entirely in the centuries to come.
Don’t let cold weather deter you, though be sure to bundle up, pour a hot toddy (or tea or coffee, as alcohol impacts the night vision) and keep a spare set of batteries in a warm pocket for that DSLR camera, as cold temps can kill battery packs quicker than you can say Custos Messium, the Harvest Keeper.
And though it may be teeth-chatteringly cold where you live this weekend, we actually reach our closest point to the Sun this Sunday, as Earth reaches perihelion on January 4th at around 8:00 UT, just 5 hours after the Quads are expected to peak. We’re just over 147 million kilometres from the Sun at perihelion, a 5 million kilometre difference from aphelion in July. Be thankful we live on a planet with a relatively circular orbit. Only Venus and Neptune beat us out in the true roundness department!
…and no, you CAN’T defy gravity around perihelion, despite the current ill conceived rumor going ‘round ye ole net…
And as a consolation prize to southern hemisphere observers, the International Space Station reaches a period of full illumination and makes multiple visible passes starting December 30th until January 3rd. This happens near every solstice, with the December season favoring the southern hemisphere, and June favoring the northern.
A 2003 south bound Quad nabbed from Cabo Rojo, Puerto Rico (Yes, that’s the Southern Cross!) Credit and Copyright: Frankie Lucena.
So don’t let the relatively bad prospects for the 2015 Quadrantids deter you: be vigilant, report those meteor counts to the IMO, send those meteor pics in to Universe Today and tweet those Quads to #Meteorwatch. Let’s “party like it’s 1899,” and get the namesake of an archaic and antiquated constellation trending!
Comet C/2014 Q2 Lovejoy photographed overnight December 28-29, 2014 remotely from Siding Spring, Australia as passed within 1/6 degree of the globular cluster M79. The coma glows green from fluorescing carbon molecules while the narrow ion tail is carbon monoxide gas fluorescing in UV sunlight. Credit: Rolando Ligustri
Oh my, oh my. Rolando Ligustri captured this scene last night as Comet Q2 Lovejoy swished past the globular cluster M79 in Lepus. If you’ve seen the movie Wild or read the book, you’ll be familiar with the phrase “put yourself in the way of beauty”, a maxim for living life adopted by one of its characters. When I opened up my e-mail today and saw Rolando’s photo, I felt like the beauty truck ran right over me.
Another striking image of the comet’s juxtaposition with the globular cluster M79. Lovejoy is presently 48 million miles from Earth; the cluster lies at the immense distance of 41,000 light years. Credit: Chris Schur
More beautiful images arrived later including this one by Chris Schur of Arizona.
Even with the Moon at first quarter phase, the comet was plainly visible in binoculars last night shining at magnitude +5. I used 8x40s and had no problem seeing Lovejoy’s blobby glow. With a coma about 15-20 arc minutes in diameter or more than half the size of a the Full Moon, it really fills up the field of view when seen through a telescope at low to medium magnification.
A tighter view of the top image shows not only the star cluster but also shows 13th magnitude NGC 1886, an edge-on spiral galaxy. Credit: Rolando Ligustri
If you love the aqua blue hues of the Caribbean, Lovejoy will remind you it’s time to book another tropical vacation. In both my 15-inch (37-cm) and 10-inch (25-cm) reflectors, the coma glowed a delicious pale blue-green in contrast to the pearly white cluster. I encourage you to look for the comet in the next few nights before the Moon is full. Starting on January 6-7, the Moon begins its move out of the evening sky, giving observers with dark skies a chance to view Lovejoy with the naked eye. I’m looking forward to seeing its long, faint tail twist among the stars of Eridanus as the comet rapidly moves northward over the next week.
Using Photoshop I made this drawing of the comet and cluster that captures its visual appearance through the telescope last night December 28th. The nuclear region is very intense and bright and about 10 arc seconds across. Credit: Bob King
For a map on how to find the comet, check my recent article on Lovejoy’s many tails. Cheers to finding beauty the next clear night!
Comet Lovejoy was bright enough to nab in a 15-second time exposure with a 200mm telephoto lens last night. Details: f/2.8 at 13 seconds. Credit: Bob King
The half-moon creeps up on the planet Uranus this evening. The two will be near each other all night in the constellation Pisces, but closest - less than one-third of a moon diameter apart - just before midnight (CST). The views are what you'll see in a pair of binoculars. The 4th magnitude star Delta Piscium is at top in the field. Source: Stellarium
Sunlight. Moonlight. Starlight. I saw all three for the first time in weeks yesterday. Filled with photons, I feel lighter today, less burdened. Have you been under the clouds too? Let’s hope it’s clear tonight because there’s a nice event you’ll want to see if only because it’s so effortless.
The half-moon will pass very close to the planet Uranus for skywatchers across North America this evening Sunday, Dec. 28th. Pop the rubber lens caps off those binoculars and point them at the Moon. If you look a short distance to the left you’ll notice a star-like object. That’s the planet!
Seattle, two time zones west of the Midwest, will see the two closest around 9:30 p.m. local time. Source: Stellarium
You can do this anytime it’s dark, but the later you look the better because the Moon moves eastward and closer to the planet as the hours tick by. Early in the evening, the two will be separated by a couple degrees, but around 11:30 p.m. CST (9:30 p.m. PST) when the Moon reclines in the western sky, the planet will dangle like an solitary diamond less than a third of a lunar diameter away. When closest to the Moon, Uranus may prove tricky to see in its glare. If you hide the Moon behind a chimney, roofline or power pole, you’ll find it easier to see the planet.
The farther north you live, the closer the twain will be. Skywatchers in Japan, the northeastern portion of Russia, northern Canada and Alaska will see the Moon completely hide Uranus for a time. The farther west you are, the higher the Moon will be when they conjoin. West Coast states see the pair highest when they’re closest, but everyone will get a good view.
Binocular view from the desert city of Tucson around 10:45 p.m. local time tonight. You can see that the Moon is a little farther north of the planet compared to the view from Seattle. The 1,500 miles between the two cities is enough to cause our satellite, which is relatively close to the Earth, to shift position against the background stars. Source: Stellarium
When closest, the radically different character of each world can best be appreciated in a telescope. Pump the magnification up to 150x and slide both planet and Moon into the same field of view. Uranus, a pale blue dot, wears a permanent cover of methane-laced clouds where temperatures hover around -350°F (-212°C).
Though the Moon will be lower in the sky in the eastern U.S. and Canada when it’s closest to Uranus, observers there will still see planet and Moon only 1/2 degree apart shortly before moonset. Source: Stellarium
The fantastically large-appearing Moon in contrast has precious little atmosphere and its sunny terrain bakes at 250°F (121°C). And just look at those craters! First-quarter phase is one of the best times for Moon viewing. The terminator or shadow-line that divides lunar day from night slices right across the middle of the lunar landscape.
Shadows cast by mountain peaks and crater rims are longest and most dramatic around this time because we look squarely down upon them. At crescent and gibbous phases, the terminator is off to one side and craters and their shadows appear scrunched and foreshortened.
The day-night line or terminator cuts across a magnificent landscape rich with craters and mountain ranges emerging from the lunar night. Several prominent lunar “seas” or maria and prominent craters are shown. Credit: Christian Legrand and Patrick Chevalley / Virtual Moon Atlas
Enjoy the tonight’s conjunction and consider the depth of space your view encompasses. Uranus is 1.85 billion miles (2.9 billion km) from Earth today, some 7,700 times farther away than the half-moon.
Panel of negative images showing the tail of Comet Lovejoy disconnecting. Credit: Hisayoshi Kato
Maybe you’ve seen Comet Q2 Lovejoy. It’s a big fuzzy ball in binoculars low in the southern sky in the little constellation Lepus the Hare. That’s the comet’s coma or temporary atmosphere of dust and gas that forms when ice vaporizes in sunlight from the nucleus. Until recently a faint 3° ion or gas tail trailed in the coma’s wake, but on and around December 23rd it snapped off and was ferried away by the solar wind. Just as quickly, Lovejoy re-grew a new ion tail but can’t seem to hold onto that one either. Like a feather in the wind, it’s in the process of being whisked away today.
Magnetic field lines bound up in the sun’s wind pile up and drape around a comet’s nucleus to shape the blue ion tail. Notice the oppositely-directed fields on the comet’s backside. The top set points away from the comet; the bottom set toward. In strong wind gusts, the two can be squeezed together and reconnect, releasing energy that snaps off a comet’s tail. Credit: Tufts University.
Easy come, easy go. Comets usually have two tails, one of dust particles that reflect sunlight and another of ionized gases that fluoresce in Sun’s ultraviolet radiation. Ion tails form when cometary gases, primarily carbon monoxide, are ionized by solar radiation and lose an electron to become positively charged. Once “electrified”, they’re susceptible to magnetic fields embedded in the high-speed stream of charged particles flowing from the Sun called the solar wind. Magnetic field lines embedded in the wind drape around the comet and draw the ions into a long, skinny tail directly opposite the Sun.
Part of Comet Lovejoy Q2’s ion tail (left) cuts the cord and floats away from the comet as photographed on December 23, 2014. Carbon monoxide in the tail fluoresces blue in ultraviolet sunlight. Credit: Chris Schur
Disconnection events happen when fluctuations in the solar wind cause oppositely directed magnetic fields to reconnect in explosive fashion and release energy that severs the tail. Set free, it drifts away from the comet and dissipates. In active comets, the nucleus continues to produce gases, which in turn are ionized by the Sun and drawn out into a replacement appendage. In one of those delightful coincidences, comets and geckos both share the ability to re-grow a lost tail.
Comet Encke tail disconnection April 20, 2007 as seen by STEREO
Comet Halley experienced two ion tail disconnection events in 1986, but one of the most dramatic was recorded by NASA’s STEREO spacecraft on April 20, 2007. A powerful coronal mass ejection (CME) blew by comet 2P/Encke that spring day wreaking havoc with its tail. Magnetic field lines from the plasma blast reconnected with opposite polarity magnetic fields draped around the comet much like when the north and south poles of two magnets snap together. The result? A burst of energy that sent the tail flying.
Diagram showing how a CME slammed into Comet Encke (B) and snapped off its tail. Soon enough, the comet grew a new one (D). Credit: NASA
Comet Lovejoy may have also crossed a sector boundary where the magnetic field carried across the Solar System by Sun’s constant breeze changed direction from south to north or north to south, opposite the magnetic domain the comet was immersed in before the crossing. Whether solar wind flutters, coronal mass ejections or sector boundary crossings, more tail budding likely lies in Lovejoy’s future. Like the chard in your garden that continues to sprout after repeated snipping, the comet seems poised to spring new tails on demand.
Comet Lovejoy picks up speed in late December as it travels from southern Lepus into Eridanus. Its position shown nightly at 10 p.m. (CST). On Sunday night December 28th it passes very close to the bright globular cluster M79. Stars shown to magnitude +8.0. Source: Chris Marriott’s SkyMap software
If you haven’t seen the comet, it’s now glowing at magnitude +5.5 and faintly visible to the naked eye from a dark sky site. Without an obvious dust tail and sporting a faint ion tail(s), the comet’s basically a giant coma, a fuzzy glowing ball easily visible in a pair of binoculars or small telescope.
A second tail disconnection event recorded on December 26, 2014 by John Nassr from his observatory in Baguio, Philippines. The frame is 3° wide. Credit: John Nassr
In a very real sense, Comet Lovejoy experienced a space weather event much like what happens when a CME compresses Earth’s magnetic field causing field lines of opposite polarity to reconnect on the back or nightside of the planet. The energy released sends millions of electrons and protons cascading down into our upper atmosphere where they stimulate molecules of oxygen and nitrogen to glow and produce the aurora. One wonders whether comets might even experience their own brief auroral displays.
Excellent visualization showing how magnetic fields line on Earth’s nightside reconnect to create the rain of electrons that cause the aurora borealis. Notice the similarity to comet tail loss.
Now in its seventh year of compilation and the second year running on Universe Today, we’re proud to feature our list of astronomical happenings for the coming year. Print it, bookmark it, hang it on your fridge or observatory wall. Not only is this the yearly article that we jokingly refer to as the “blog post it takes us six months to write,” but we like to think of it as unique, a mix of the mandatory, the predictable and the bizarre. It’s not a 10 ten listicle, and not a full-fledged almanac, but something in between.
A rundown of astronomy for 2015: There’s lots of astronomical action to look forward to in the coming year. 2015 features the minimum number of eclipses that can occur, two lunars and two solars. The Moon also reaches its minimum standstill this coming year, as its orbit runs shallow relative to the celestial equator. The Moon will also occult all naked eye planets except Saturn in 2015, and will occult the bright star Aldebaran 13 times — once during every lunation in 2015. And speaking of Saturn, the rings of the distant planet are tilted an average of 24 degrees and opening to our line of sight in 2015 as they head towards their widest in 2018.
Finally, solar activity is trending downwards in 2015 after passing the sputtering 2014 maximum for solar cycle #24 as we now head towards a solar minimum around 2020.
Our best bets: Don’t miss these fine celestial spectacles coming to a sky near YOU next year:
– The two final total lunar eclipses in the ongoing tetrad, one on April 4th and September 28th.
– The only total solar eclipse of 2015 on March 20th, crossing the high Arctic.
– A fine dusk pairing of the bright planets Jupiter and Venus on July 1st.
– Possible wildcard outbursts from the Alpha Monocerotid and Taurid meteors, and a favorable New Moon near the peak of the August Perseids.
– Possible naked eye appearances by comet Q2 Lovejoy opening 2015 and comet US10 Catalina later in the year.
– The occultation of a naked eye star for Miami by an asteroid on September 3rd.
– A series of fine occultations by the Moon of bright star Aldebaran worldwide.
The rules: The comprehensive list that follows has been lovingly distilled down to the top 101 astronomical events for 2015 worldwide. Some, such as lunar eclipses, are visible to a wide swath of humanity, while others, such as many of the asteroid occultations or the sole total solar eclipse of 2015 happen over remote locales. We whittled the list down to a “Top 101” using the following criterion:
Meteor showers: Must have a predicted ZHR greater than 10.
Conjunctions: Must be closer than one degree.
Asteroid occultations: Must have a probability ranking better than 90 and occult a star brighter than magnitude +8.
Comets: Must reach a predicted brightness greater than magnitude +10. But remember: comets don’t always read prognostications such as this, and may over or under perform at whim… and the next big one could come by at any time!
Times quoted are geocentric unless otherwise noted, and are quoted in Universal Time in a 24- hour clock format.
These events are meant to merely whet the appetite. Expect ‘em to be expounded on fully by Universe Today as they approach. We linked to the events listed where possible, and provided a handy list of resources that we routinely consult at the end of the article.
Got it? Good… then without further fanfare, here’s the top 101 astronomical events for 2015 in chronological order:
The path of Comet Q2 Lovejoy from January 1st to January 31st. Created using Starry Night Education software.
29- The Moon occults Aldebaran at ~17:31 UT for the Arctic, marking the first of 13 occultations of the star by the Moon in 2015.
The view at 6:40 UT on January 24th, as 3 of Jupiter’s moons cast shadows on to the Jovian cloud tops simultaneously. Created using Starry Night Education software.
February
01- Venus passes 0.8 degrees south of Neptune at ~17:00 UT.
05- Earth crosses through Jupiter’s equatorial plane, marking the middle of occultation and eclipse season for the Galilean moons.
06- Jupiter reaches opposition at ~18:00 UT.
18- A “Black Moon” occurs, in the sense of the third New Moon in a season with four.
22- Venus passes 0.4 degrees south of Mars at 5:00 UT.
24- Mercury reaches greatest morning elongation at 26.7 degrees west of the Sun at 19:00 UT.
21- Io and Ganymede both cast shadows on Jupiter from 00:04 to 00:33 UT.
21- Callisto and Europa both cast shadows on Jupiter from 13:26 to 13:59 UT.
23- Saturn reaches opposition at ~1:00 UT.
24- Asteroid 1669 Dagmar occults the +1st magnitude star Regulus at ~16:47 UT for the Arabian peninsula,
the brightest star occulted by an asteroid for 2015.
28- Ganymede and Io both cast shadows on Jupiter from 02:01 to 04:18 UT.
30- Comet 19P/Borrelly may reach binocular visibility.
June
01- The International Space Station reaches full illumination as the June solstice nears, resulting in multiple nightly passes favoring northern hemisphere observers.
04- Io and Ganymede both cast shadows on Jupiter from 4:54 to 6:13 UT.
05- Venus reaches greatest eastern (dusk) elongation for 2015, 45 degrees from the Sun at 16:00 UT.
10- Asteroid 424 Gratia occults a +6.1 magnitude star at ~15:10 UT for northwestern Australia.
13- The Perseid meteors peak from 06:30 to 09:00 UT, with a maximum predicted ZHR of 100 favoring North America.
19- Mars crosses the Beehive Cluster M44.
28- Asteroid 16 Psyche occults a +6.4 magnitude star at ~9:49 UT for Bolivia and Peru.
29- Supermoon 1 of 3 for 2015: The Moon reaches Full at 18:38 UT, 20 hours from perigee.
The path of the Moon through the Earth’s shadow on September 28th. Credit: Fred Espenak/NASA/GSFC
September
01- Neptune reaches opposition at ~3:00 UT.
03- Asteroid 112 Iphigenia occults a +3rd magnitude star for Mexico and Miami at ~9:20 UT. This is the brightest star occulted by an asteroid in 2015 for North America.
02- Geostationary satellite and SDO eclipse season begins as we approach the September equinox.
04- Mercury reaches its greatest elongation for 2015, at 27 degrees east of the Sun at 8:00 UT in the dusk skies.
05- The Moon occults Aldebaran for northeastern North America at ~5:38 UT.
13- “Shallow point” (also known as the minor lunar standstill) occurs over the next lunation, as the Moon’s orbit reaches a shallow minimum of 18.1 degrees inclination with respect to the celestial equator… the path of the Moon now begins to widen towards 2025.
13- A partial solar eclipse occurs, centered on 6:55 UT crossing Africa and the Indian Ocean.
25- Mars passes 0.8 degrees from Regulus at ~4:00 UT.
28- A total lunar eclipse occurs centered on 2:48 UT, visible from the Pacific, the Americas and eastern Europe.
28- Supermoon 2 of 3 for 2015: The Moon reaches Full at 2:52 UT, approximately an hour from perigee. This marks the closest Full Moon of the year.
The path of the September 3rd occultation of a +3rd magnitude star by an asteroid over central Mexico and the Florida Keys. Credit: IOTA/Steve Preston.
The Moon occults Aldebaran: the visibility footprint for North America. The dashed line denotes the area in which the event occurs during the daytime. Credit: Occult 4.1.0.11.
November
01- Io and Ganymede both cast shadows on Jupiter from 17:36 to 17:47 UT.
02- Venus passes 0.7 degrees south of Mars at 00:30 UT.
12- Will the 7 year “Taurid fireball meteor shower” produce?
18- The Leonid meteor shower peaks at 04:00 UT, with an estimated ZHR of 15 favoring Europe.
22- Are we in for a once per decade Alpha Monocerotids outburst? The 2015 peak arrives at 4:25 UT, favoring Europe… with a max ZHR = 400+ possible.
The daytime occultation of Venus by the Moon over North America on December 7th.Credit: Occult 4.1.0.11.
December
01- The International Space Station reaches full illumination as the December solstice nears, resulting in multiple nightly passes favoring the southern hemisphere.
04- Mercury occults the +3.3 magnitude star Theta Ophiuchi for South Africa at 16:16 UT prior to dusk.
06- The Moon occults Mars for central Africa at ~2:42 UT.
07- The Moon occults Venus in the daytime for North America at ~16:55 UT.
14- The Geminid meteor shower peaks at 18:00 UT, with a ZHR=120 favoring NE Asia.
Keeping warm? Yesterday marked the start of astronomical winter for the northern hemisphere, meaning long nights and (hopefully) clear, cold skies. But we’ve also got another reason to brave the cold this week, as Comet C/2014 Q2 Lovejoy is set to put on a show for northern hemisphere observers.
Already, Comet Q2 Lovejoy has been providing southern hemisphere observers with a fine celestial showing. Discovered by Australian comet hunter extraordinaire Terry Lovejoy on August 17th of this year as it glided across the constellation Puppis, Q2 Lovejoy has been brightening through early December ahead of expectations. We’ve already been getting some great images from Universe Today readers down south, and we can expect more in the weeks to come. This is Mr. Lovejoy’s fifth comet discovery, and many will remember how comet C/2011 W3 Lovejoy also survived a perilous perihelion passage just 140,000 kilometres from the surface of the Sun during the 2011 holiday season and went on to produce a brilliant display.
Q2 Lovejoy plus negative image taken from New Mexico on December 20th. Credit and copyright: Joseph Brimacombe.
Currently shining at magnitude +5.5, Q2 Lovejoy is a fine target for binoculars or a small telescope as it crosses the southern constellation of Columba into Lepus just after Christmas Day. Sirius currently makes a good guidepost, as the comet sits about 19 degrees southeast of the brightest star in the sky. And speaking of Sirius, don’t forget to try your hand at spotting its white dwarf companion in 2015!
A black and white view of Comet Lovejoy, taken on Dec. 21, 2014, highlighting the comet’s dramatic tail. Credit and copyright: Damian Peach.
Q2 Lovejoy also has a high orbital inclination of 80.3 degrees relative to the ecliptic, which is good news, as it will be plunging rapidly northward as it makes its closest passage by Earth on January 7th at 70.2 million kilometres or 0.47 A.U.s distant. Note that not only will the comet pass extremely close to the globular cluster M79 (photo op!) on the night of December 29th, but will also pass within 10 degrees of the Pleiades in January before threading its way northward between the famous Double Cluster in Perseus and the Andromeda Galaxy.
Clouded out? You can catch Comet Q2 Lovejoy courtesy of Gianluca Masi and our good friends over at the Virtual Telescope Project live on January 6th and January 11th at 19:00 Universal Time/2:00 PM EST on both dates:
Note: the photo is of Comet C/2014 E2 Jacques from earlier this year. (Credit: the Virtual Telescope Project).
Expect Q2 Lovejoy to ride highest to the south around local midnight starting on January 1st, and transit the local meridian at 8-9 PM local by mid-month. Keen eyed observers have already managed to spy Q2 Lovejoy unaided from a dark sky site, and we expect this to be the general case for most observers by New Year’s Day. As of this writing, Q2 Lovejoy displays a fine coma 10’ wide with a 7 degree long, fan-shaped tail.
Comet Q2 Lovejoy imaged from Siding Spring Observatory in New South Wales, Australia on December 18th. Credit and copyright: Roger Hutchinson.
Here’s our handy blow-by-blow for Comet Q2 Lovejoy in the coming weeks:
December
28- Crosses into the constellation Lepus.
29- Passes less than 10’ — a third of the diameter of the Full Moon — from the 7.7 magnitude globular cluster NGC 1904 (Messier 79).
The path of Comet Q2 Lovejoy from December 23rd through February 1st. Credit: Starry Night Education software.
January
1- May break naked eye visibility at magnitude +6.
2- Passes into the constellation Eridanus and reaches opposition at 0.49 A.U.s from the Earth.
5- The Moon reaches Full, hampering observations.
7- May reach a peak brightness at +4th magnitude.
7- Passes closest to Earth 0.47 AU, moving at an apparent speed of almost 3 degrees a day.
9- Crosses the celestial equator into the constellation Taurus.
17- Crosses the ecliptic plane and into the constellation Aries.
20- Moon reaches New phase, marking a favorable span for observation.
22- Passes within one degree of the 3.6 magnitude star 41 Arietis.
25- Crosses into the constellation Triangulum.
30- Reaches perihelion at 1.29 A.U.
30- Crosses into the constellation Andromeda.
The position of Q2 Lovejoy on New Year’s Day. Credit: NASA/JPL.
February
3- The Moon reaches Full phase, hampering observations.
4- Passes less than one degree from the 2.1 magnitude star Gamma Andromedae (Almach).
18- The Moon reaches New, marking a favorable span of time for observations.
20- Passes less than a degree from the +4th magnitude star Phi Persei and into the constellation Perseus.
March
1- May drop below naked eye visibility.
2- Crosses into the constellation Cassiopeia.
5- The Moon reaches Full phase, hampering observations.
11- Passes less than one degree from the +5 magnitude Owl Cluster.
16- Passes less than one degree from the 2.6 magnitude star Delta Cassiopeiae (Ruchbah).
20- The Moon reaches New, marking a favorable time for observation.
From there, Comet Q2 Lovejoy drops back below +10th magnitude and passes just a degree from the north celestial pole in late May as it heads back out of the inner solar system. Q2 Lovejoy was on a 13,500 year orbit inbound, and its passage through the inner solar system shortened its orbit by about 5,000 years. Just think, about 13 millennia ago, Mesolithic man was busy domesticating early farm animals. Did they, by chance, look up and catch sight of Comet Q2 Lovejoy? And who will be here to ponder its return passage eight millennia hence?
Comet hunting is fun and easy… we prefer to sweep the target area with our trusty Canon 15×45 image stabilized binoculars, though a common pair of 7x 50’s — often favored by hunters and bird watchers — will do just fine. The passage by +7.7 magnitude globular cluster M79 this week will provide a fine contrast in “fuzz balls…” Remember, in comets as in nebulae, the quoted magnitude is often dispersed over a broad surface area, making the objects fainter than a pinpoint star of the same brightness.
And Comet Q2 Lovejoy is the first of several binocular comets to look forward to in 2015. Right now, we’ve got our money on comets C/2014 Q1 PanSTARRS, 19P/Borrelly, C/2013 US10 Catalina, and C/2013 X1 PanSTARRS as possible contenders in 2015. And don’t miss +9th magnitude Comet 15P/Finlay, currently in outburst and playing tag with the planet Mars low in the dusk sky.
Watch this space (bad pun intended) this coming Friday for the low down on all things astronomical in 2015!
-Got pics of Comet Q2 Lovejoy? Send ’em in to Universe Today.
Comet Finlay on December 16th showing a bright coma and short tail. Credit: FRAM team
Short-period comet 15P/Finlay, which had been plunking along at a dim magnitude +11, has suddenly brightened in the past couple days to +8.7, bright enough to see in 10×50 or larger binoculars. Czech comet observer Jakub Cerny and his team photographed the comet on December 16th and discovered the sudden surge. Wonderful news!
While comets generally brighten as they approach the Sun and fade as they depart, any one of them can undergo a sudden outburst in brightness. You can find Finlay right now low in the southwestern sky at nightfall near the planet Mars. While outbursts are common, astronomers still aren’t certain what causes them. It’s thought that sub-surface ices, warmed by the comet’s approach to the Sun, expand until the pressure becomes so great they shatter the ice above, sending large fragments flying and exposing fresh new ice. Sunlight gets to work vaporizing both the newly exposed vents and aerial shrapnel. Large quantities of dust trapped in the ice are released and glow brightly in the Sun’s light, causing the comet to quickly brighten.
Some comets flare up dramatically. Take 29P/Schwassmann-Wachmann. Normally a dim bulb at 17th magnitude, once or twice a year it flares to magnitude 12 and occasionally 10!
Animated movie showing the expansion of the coma of Comet Holmes over 9 nights during its spectacular outburst in November 2007. Credit: 3.6-meter Canada-France-Hawaii telescope on Mauna Kea / David Jewitt
Whatever the reason, outbursts can last from days to weeks. It’s anybody’s guess how long 15P/Finlay will remain a relatively easy target for comet hungry skywatchers. While not high in the sky, especially from the northern U.S., it can be seen during early evening hours if you plan well.
By good luck, Comet Finlay will track with Mars through December into early January. On December 23rd, they’ll come together in a remarkably close conjunction. This map shows the nightly position of the comet from Dec. 18th through Jan. 12th. Mars’ location is shown every 5 nights. Positions plotted for 6:15 p.m. (CST) 1 hour and 45 minutes after sunset. Stars shown to magnitude 8. Star magnitudes are underlined. Click to enlarge and print for outside use. Source: Chris Marriott’s SkyMap software
Comet Finlay was discovered by William Henry Finlay from South Africa on September 26, 1886. It reaches perihelion or closest approach to the Sun on December 27th and was expected to brighten to magnitude +10 when nearest Earth in mid-January at 130 million miles (209 million km). Various encounters with Jupiter since discovery have increased its original period of 4.3 years to the current 6.5 years and shrunk its perihelion distance from 101 million to 90 million miles.
Comet Finlay appears considerably fainter in this pre-outburst photo taken on December 14th. Credit: Alfons Diepvens
Looking at the map above it’s amazing how closely the comet’s path parallels that of Mars this month. Unlike Comet Siding Spring’s encounter with that planet last October, Finlay’s proximity is line of sight only. Still, it’s nice to have a fairly bright planet nearby to point the way to our target. Mars and Finlay’s paths intersect on December 23rd, when the duo will be in close conjunction only about 10? apart (1/3 the diameter of the Full Moon) for observers in the Americas. They’ll continue to remain almost as close on Christmas Eve. Along with Comet Q2 Lovejoy, this holiday season is turning out to be a joyous occasion for celestial fuzzballs!
To give you a little context to make finding Comet FInlay easier, use this wide-view map. A line from bright Vega in the western sky left through Altair will take you directly to Mars and the comet. This map shows the sky at nightfall tonight when the comet will be about 15° high in the southwestern sky. Source: Stellarium
Astronomy is all about thinking big, both in time and space.
The Earth turns on its axis, the Moon passes through its phases, and the planets come into opposition and solar conjunction on a routine basis.
Of course, on the other end of the spectrum, there are some events which traverse such colossal spans of time that the mere mortal life span of measly homo sapiens such as ourselves can never expect to cover them. Many comets have periods measured in centuries, or thousands of years. The axis of the Earth wobbles like a top, completing one turn every 26,000 years in what’s known as the Precession of the Equinoxes. Our solar system completes one revolution about the galactic center every quarter billion years…
Feeling puny yet? Sure, astronomy is also about humility. But among these stupendous cycles, there are some astronomical events that you just might be able to live through. One such instance is the orbits of double stars. And as 2015 approaches, we challenge you to see of the most famous white dwarf of them all, as it reaches a favorable viewing position over the next few years: Sirius B.
Sirius A and B in x-rays courtesy of Chandra. Credit: NASA/SAO/CXC.
Sirius itself is easy to find, as it’s the brightest star in Earth’s sky shining at magnitude -1.42. In fact, you can spot Sirius in the daytime sky if you know exactly where to look.
But it is one of the ultimate in cosmic ironies that the most conspicuous of stars in our sky also hosts such an elusive companion. The discovery of Sirius B awaited the invention of optics capable of resolving it next to its dazzling host. Alvan Clark Jr. and Sr. first spied the enigmatic companion on January 31st, 1862 while testing their newly constructed 18.5 inch refractor, which was the largest at the time. The discovery was soon verified from the Harvard College Observatory, adding Sirius A and B to the growing list of multiple stars.
A 19th century refractor similar to the one used to discover Sirius B. Photo by the author.
And what a strange companion it turned out to be. Today, we know that Sirius B is a white dwarf, the cooling dense ember of a main sequence star at the end of its life. We call the matter in such a star degenerate, not as a commentary on its moral stature, but the state the electrons and the closely packed nuclei within under extreme pressure. Our Sun will share the same ultimate fate as Sirius B, about six billion years from now.
A comparison of a white dwarf (center) and our Sun (right) Credit: RJHall/Wikimedia Commons.
The challenge, should you choose to accept it, is to spot Sirius B in the glare of its host. The contrast in brightness between the pair is daunting: shining at magnitude +11, the B companion is more than 63,000 times fainter than -1.46 magnitude Sirius A.
The changing position angle of Sirius B. Note that the graphic is inverted, with north at the bottom. Created by the author.
A feat of visual athletics, indeed. Still, Sirius B breaks 10” in separation from its primary in 2015, as it heads towards apastron — its most distant point from its primary, at just over 11” in separation — in 2019. Sirius B varies from 8.2 and 31.5 AUs from its primary. Sirius B is on a 50.1 year orbit, meaning the time to cross this one off of your life list is over the upcoming decade. Perhaps making an animation showing the motion of Sirius B from 2015-2025 would present a supreme challenge as well.
Sirius culminates at local midnight right around New Year’s Eve, shining at its highest to the south as the “ball drops” ushering in 2015. Of course, this is only a fortuitous circumstance that is possible in our current epoch, and precession and the proper motions of both Sirius and Sol will make this less so millennia hence.
Sirius crossing the meridian at local midnight on New Year’s Eve. Credit: Stellarium.
Newsflash: there’s a very special visual treat in the offing next week, as comet C/2014 Q2 Lovejoy is currently hovering around +6th magnitude and passes 19 degrees south of Sirius on Christmas Day… more to come!
Magnification and good seeing are your friends in the hunt for Sirius B. Two factors describe the position of a secondary star in a binary pair: its position angle in degrees, and separation in arc seconds. When it comes to stars that are a tough split, I find its better to estimate the position angle first before looking it up. A close match can often confirm the observation. Does a friend see the same thing at the eyepiece? A good star to “warm up” on is the +6.8 magnitude companion to Rigel in the foot of Orion, with a separation of 9”.
Nudging Sirius just out of view might allow the B companion to become apparent. Another nifty star-spliting tool is what’s known as an occulting bar eyepiece. Making an occultation bar eyepiece is easy: we’ve used everything from a small strip of foil to a piece of guitar string (heavy E gauge works nicely) for the central bar. An occulting bar eyepiece is also handy for hunting down the moons of Mars near opposition.
Sirius B also works its way into cultural myths and lore, not the least of which are the curious tales of the Dogon people of Mali. At the outset, it seems that these ancient people have knowledge of a small dense hidden companion star to Sirius, knowledge that requires modern technology to reproduce. Carl Sagan noted, however, that cultural contamination may have resulted in the late 19th century discovery of Sirius B making its way into the Dogon pantheon. The science of anthropology is rife with anecdotes that have been carefully fed to credulous anthropologists only to be reported later as fact, all in the name of a good story.
A comparison of Sirius B’s real versus apparent trajectory. Credit: SiriusB/Wikimedia Commons.
All amazing things to ponder as you begin your 2015 quest for Sirius B, a bashful but fascinating star.
UPDATE: Tune in this Sunday as the good folks over at the Virtual Telescope Project feature a live webcast covering the Geminid meteor shower this Sunday on December 14th at 2:00 UT.
This weekend presents a good reason to brave the cold, as the Geminid meteor shower peaks on the morning of Sunday, December 14th. The Geminids are dependable, with a broad peak spanning several days, and would be as well known as their summer cousins the Perseids, were it not for the fact that they transpire in the dead of northern hemisphere winter.
But do not despair. While some meteor showers are so ephemeral as to be considered all but mythical in the minds of most meteor shower observers, the Geminids always deliver. We most recently caught a memorable display of the Geminids in 2012 from a dark sky locale in western North Carolina. Several meteors per minute pierced the Appalachian night, offering up one of the most memorable displays by this or any meteor shower in recent years.
The Geminids are worth courting frostbite for, that’s for sure. But there’s a curious history behind this shower and our understanding of meteor showers in general, one that demonstrates the refusal of some bodies in our solar system to “act right” and fit into neat scientific paradigms.
A composite of the 2013 Geminids. Credit: the UK Meteor Observation Network
It wasn’t all that long ago that meteor showers — let alone meteorites — were not considered to be astronomical in origin at all. Indeed, the term meteor and meteorology have the same Greek root meaning “of the sky,” suggesting ideas of an atmospheric origin. Lightning, hail, meteors, you can kind of see how they got there.
In fact, you could actually face ridicule for suggesting that meteors had an extraterrestrial source back in the day. President Thomas Jefferson was said to have done just that concerning an opinion espoused by Benjamin Silliman of a December 14th, 1807, meteorite fall in Connecticut, leading to the apocryphal and politically-tinged response attributed to the president that, “I would more easily believe that two Yankee professors would lie, than that stones would fall from heaven.”
Indeed, no sooner than The French Academy of Sciences considered the matter settled earlier in the same decade, then a famous meteorite fall occurred in Normandy on April 26th, 1803,… right on their doorstep. The universe, it seemed, was thumbing its nose at scientific enlightenment.
Things really heated up with the spectacular display known as the Leonid meteor storm in 1833. On that November morning, stars seemed to fall like snowflakes from the sky. You can imagine the sight, as the Earth plowed headlong into the meteor stream. The visual effect of such a storm looks like the starship Enterprise plunging ahead at warp speed with stars streaming by, as if imploring humanity to get hip to the fact that meteor showers and their radiants are indeed a reality.
Still, a key problem persisted that gave ammunition to the naysayers: no new “space rocks” were found littering the ground at sunrise after a meteor shower. We now know that this is because meteor showers hail from wispy cometary debris left along intersections of the Earth’s orbit. Meteorite Man Geoff Notkin once mentioned to us that no meteorite fall has ever been linked to a meteor shower, though he does get lots of calls around Geminid season.
The name of the game in the 19th century soon became identifying new meteor showers. Streams evolve over time as they interact with planets (mostly Jupiter), and the 19th century played host to some epic meteor storms such as the Andromedids that have since been reduced to a trickle.
The Geminids are, however, the black sheep of the periodic meteor shower family. The shower was first noticed by US and UK observers in 1862, and by the 1870s astronomers realized that a new minor shower with a Zenithal Hourly Rate (ZHR) hovering around 15 was occurring near the middle of December from the constellation Gemini.
The source of the Geminids, however, was to remain a mystery right up until the late 20th century.
In the late 1940s, astronomer Fred Whipple completed the Harvard Meteor Project, which utilized a photographic survey that piqued the interest of astronomers worldwide: debris in the Geminid stream appeared to have an orbital period of just 1.65 years, coupled with a high orbital inclination. Modeling suggested that the parent body was most likely a short period comet, and that the stream had undergone repeated perturbations courtesy of Earth and Jupiter.
In 1983, the culprit was found, only to result in a deeper mystery. The Infrared Astronomical Satellite (IRAS) discovered an asteroid fitting the bill crossing the constellation Draco. Backup observations from the Palomar observatory the next evening cinched the discovery, and today, we recognize the source of the Geminids as not a comet — as is the case with every other major meteor shower — but asteroid 3200 Phaethon, a 5 kilometre diameter rock in a 524 day orbit.
Asteroid 3200 Phaethon (arrowed) imaged by Marco Langbroek from the Winer Observatory in Sonita, Arizona. Credit: Wikimedia Commons.
So why doesn’t this asteroid behave like one? Is 3200 Phaethon a rogue comet that has long since settled down for the quiet space rock life? Obviously, 3200 Phaethon has lots of material shedding off from its surface, as evidenced by the higher than normal ratio of fireballs seen during the Geminid meteors. 3200 Phaethon also passes 0.14 AUs from the Sun — 47% closer than Mercury — and has the closest perihelion of any known asteroid to the Sun, which bakes the asteroid periodically with every close pass.
One thing is for certain: activity linked to the Geminid meteor stream is increasing. The Geminids actually surpassed the Perseids in terms of dependability and output since the 1960s, and have produced an annual peak ZHR of well over 100 in recent years. In 2014, expect a ZHR approaching 130 per hour as seen from a good dark sky site just after midnight local on the morning of December 14th as the radiant rides high in the sky. Remember, this shower has a broad peak, and it’s worth starting your vigil on Saturday or even Friday morning. The Geminid radiant also has a steep enough declination that local activity can start before midnight… also exceptional among meteor showers. This year, the 52% illuminated Moon rises around midnight local on the morning of December 14th.
The Geminid radiant looking to the northeast at 11PM local. Note the radiant of the December 22nd Ursids is also nearby. Credit: Stellarium.
And there’s another reason to keep an eye on the 2014 Geminids. 3200 Phaethon passed 0.12 AU (18 million kilometers) from Earth on December 10th, 2007, which boosted displays in the years after. And just three years from now, the asteroid will pass even closer on December 10th, 2017, at just 0.07 AUs (10.3 million kilometers) from Earth…
Are we due for some enhanced activity from the Geminids in the coming years?
All good reasons to bundle up and watch for the “Tears of the Twins” this coming weekend, and wonder at the bizzaro nature of the shower’s progenitor.
Look high in the southern sky at nightfall to find the familiar giant square that forms part of the body of Pegasus the Flying Horse. The map shows the sky around 6:30 p.m. local time. Source: Stellarium
Cast your gaze up, up, up on the next dark, moonless night and stare into the Great Square of Pegasus. How many stars do you see? Zero? Two? Twenty? If you’d like to find out how dark your sky is, read on.
The Great Square, one of the fall sky’s best known star patterns, rides high in the south at nightfall in mid-December. It forms part of the larger figure of Pegasus the Winged Horse. For our purposes today, we’re going to concentrate on what’s inside the square.
Bounded by Alpheratz (officially belonging to adjacent Andromeda), Scheat, Markab and Algenib, the Great Square is about 15° on a side or one-and-a-half balled fists held at arm’s length.
At first glance, the space appears empty, but a closer look from all but the most light polluted skies will reveal a pair 4th magnitude stars in the upper right quadrant of the square. Fourth magnitude is about the viewing limit from a bright suburban location.
Astronomers use the magnitude scale to measure star and planet brightness. Each magnitude is 2.5 times brighter than the one below it. Aldebaran, which shines at 1st magnitude, is 2.5 times brighter than a 2nd magnitude star, which in turn is 2.5 times brighter than a 3rd magnitude star and so on.
Moonlight and especially light pollution reduce the number of stars we can see in the night sky. This specially prepared map shows slices of sky based on amateur astronomer and author John Bortle’s Dark Sky Scale. Classes range from 1 (excellent with stars fainter than 7th magnitude visible) to 9 (inner city with a limiting magnitude of 4). Click for more detailed descriptions of each class and rate your own sky. Credit: International Dark Sky Association
A first magnitude star is 2.5 x 2.5 x 2.5 x 2.5 x 2.5 (about 100) times brighter than a 6th magnitude star. The bigger the magnitude number, the fainter the star. From cities, you might see 3rd magnitude stars if you can block out stray lighting, but a dark country sky will deliver the Holy Grail naked eye limit of magnitude 6. Skywatchers with utterly dark conditions might glimpse stars as faint 7.5. My own personal best is 6.5.
With each drop in magnitude the number of stars you can see increases exponentially. There are only 22 first magnitude or brighter stars compared to 5,946 stars down to magnitude 6.
What appears blank at first is filled with stars — 26 of them down to magnitude 6.3 are visible inside the Great Square from a dark sky site. How many can you see? Click for a larger version. Source: Stellarium
Ready to stretch your sight and rate your night sky? Step outside at nightfall and allow your eyes to dark-adapt for 20 minutes. With a copy of the map (above) in hand, start with the brightest stars and work your way to the faintest. Each every small step down the magnitude ladder prepares your eyes the next.
With a little effort you should be able to spot the four 4th magnitude range stars. At magnitude 5, you’ll work harder. Moving beyond 5.5 can be very challenging. I revert to averted vision to corral these fainties. Instead of staring directly at the star, play your eye around it. Look a bit to this side and that. This allows a rod-rich part of the retina that’s excellent at seeing faint stuff play through the scene and snatch up the faintest possible stars.
Magnitude scale showing the limits of the eye, binoculars and telescopes. Credit: Dr. Michael Bolte, UCO/Lick Observatory
From my house I can pick out about dozen points of light inside the Square on a moonless night. How many will you see? Once you know your magnitude limit, compare your result to John Bortle’s Dark Sky Scale … and weep. No, just kidding. But his Class 1 excellent sky includes a description of seeing stars down to magnitude 8 and the summer Milky Way casting shadows.
Hard to believe that before about 1790, when gas lighting was introduced in England, Class 1 skies were the norm across virtually the entire planet. Nowadays, most of us have to drive a hundred miles or more to experience true, untrammeled darkness.
Have fun with the challenge and let us know in the comments area how you do. Here’s hoping you find the Great Square far from vacant.
