The coming weeks are a great time to catch comet C/2020 R4 ATLAS… while you can.
Looking to do some springtime astronomy? With temperatures warming up in the northern hemisphere in April through May, galaxy season is upon us. At dusk, the area in the Bowl of Virgo asterism rising in the east is rife with clusters of galaxies that spill over into the adjacent constellations of Coma Berenices and Boötes…
But this May, keep an eye out for a fuzzball interloper that is not a galaxy: Comet C/2020 R4 ATLAS.
Got clear skies? If you’re like us, you’ve been putting the recent pandemic-induced exile to productive use, and got out under the nighttime sky. And though 2020 has yet to offer up a good bright ‘Comet of the Century’ to keep us entertained, there have been a steady stream of good binocular comets for northern hemisphere viewers, including C/2017 T2 PanSTARRS and C/2019 Y4 ATLAS. This week, I’d like to turn your attention to another good binocular comet that is currently at its peak: the ‘other’ comet ATLAS, C/2019 Y1 ATLAS.
Miss out on Comet 45/P Honda-Mrkos-Padadušáková last month? We’ll admit, it was fairly underwhelming in binoculars… but fear not, there are several other binocular comets in the pipeline for 2017.
Maybe you managed to catch sight of periodic Comet 2P Encke in late February after sunset before it disappeared into the Sun’s glare. Pronounced (En-Key), the comet actually passes through the field of view of the joint NASA/ESA Solar Heliospheric Observatory’s (SOHO) LASCO C3 camera from March 8th to March 14th before reemerging in the dawn sky.
I see you… Comet 2P Encke is now in SOHO’s LASCO C3 field of view, above Mercury (the bright object) moving in the opposite direction: pic.twitter.com/gcYwv0Sdkp
Northern hemisphere observers have already got a sneak peek at Encke’s performance low in the dusk in February as it heads towards perihelion. Now the comet heads southward, as it vaults up into the dawn sky for folks south of latitude 30 degrees north in mid-March. From latitude 30 degrees north, Encke will clear 15 degrees elevation above the southeastern horizon around March 31st. Viewers south of the equator will have a much better viewing prospect, as Encke glides southward through Aquarius. When will you first spot it?
Also: don’t forget to ‘spring forward’ to Daylight Saving Time this weekend for a majority of North America prior to beginning your dawn comet vigil… Europe and the United Kingdom gets a brief reprieve ’til March 26th.
Her are some upcoming key events for Comet 2P Encke:
Closest to Sun: March 10th, with a perihelion of 0.33 AU.
Closest to Earth: March 12th, at 0.65 AU distant.
Brightest: Around March 15. Encke is currently at magnitude +7, and should top out at magnitude +6, though it’ll only be 14 degrees from the Sun on this date.
Next good apparition: 0.4 AU from Earth in 2036.
This is Encke’s 63rd passage through the solar system since Pierre Méchain linked successive passages of the comet to the same in 1819. Like Edmond Halley, Encke didn’t discover the most famous of comets that now bears his name, but instead merely deduced its periodic nature. Halley was 1st, and Encke was second (hence the “2” in 2P…) The shortest short period comet, Encke was captured sometime thousands of years ago into its short period orbit, and is destined to burn out one day as it ventures from 4.1 to 0.33 AU from the Sun. Encke is also the source of the annual Taurid meteor shower in November, notable for producing a high rate of fireballs.
Comets can be elusive beasties, as all of that precious quoted magnitude is smeared out over an extended surface area. Add on top this the fact that comets are also notorious for often under- and occasionally over-performing expectations. Just look at the ‘none more black’ albedo of comet 67P Churumov-Gerasimenkochronicled by ESA’s Rosetta spacecraft: it’s a miracle we can see ’em at all. And finally, that low contrast dawn sky can easily hide a faint binocular comet, fading it to invisibility. Start your comet vigil early, sweeping the horizon with binocs. An early start and a clear view are key. The slim waning crescent Moon sits 12 degrees north of Comet Encke on the morning of March 26th, and the comet also passes less than 3 degrees from the Helix Nebula (NGC 7293) on (no joke) April Fool’s Day April 1st.
Flashback to one Encke orbit ago to 2013 and the comet provided a good dawn preshow to that biggest of cosmic let downs, Comet ISON. And although Encke makes its rounds every 3.3 years, orbital geometry assures that we won’t get another favorable viewing from Earth until 2036.
Speaking of great comets that never were, we juuuust missed having a spectacular comet this past month, when recently discovered long-period Comet 2017 E1 Borisov passes just 0.045 AU (!) interior to our orbit. Unfortunately, this occurs five months too early, with the Earth almost exactly at the wrong place in its orbit. Now, if it was only August…
Comet Teaser for 2017
Yeah, the gambler’s fallacy would tell us that we’re due for the next great comet of the century, for sure. In the meantime, we’ve still got Comets 41P/Tuttle-Giacobini-Kresák (late March/April), C/2015 ER61 PanSTARRS (May), and C/2015 V2 Johnson (June) on tap as good binocular comets in 2017.
Be sure to enjoy elusive comet Encke as it flits once more though the dawn skies.
Looking for a good binocular comet? Well, if luck is on our side, we should be getting our first looks at periodic Comet 45P/Honda-Mrkos-Pajdušáková as it tops +10th magnitude in dusk skies over the next few weeks.
Comet 45P/Honda-Mrkos-Pajdušáková is expected to reach maximum brightness around late February 2017. Discovered independently by astronomers Minoru Honda, Antonin Mrkos and L’udmila Pajdušáková on December 3rd, 1948, Comet 45P/Honda-Mrkos-Pajdušáková orbits the Sun once every 5.25 years on a short period orbit. Comet 45P/Honda-Mrkos-Pajdušáková is set to break binocular +10th magnitude brightness in mid-December 2017, and may reach a maximum brightness of magnitude +7 from January through February 2017.
Currently and through the end of 2016, the comet sits towards the center of the Milky Way Galaxy in Sagittarius at a faint +15th magnitude in the evening sky. The comet may break +10th magnitude and become very briefly visible in the first few weeks of December before getting too close to the Sun to observe in late 2016 and crossing into the morning sky in early 2017.
Visibility prospects: At its brightest, Comet 45P/Honda-Mrkos-Pajdušáková will be passing through the constellation Hercules during closest approach on February 11th. The comet then passes through the constellations of Corona Borealis, Boötes, Canes Venatici, Ursa Major into Leo through to the end of February as it recedes. In the second week of February, the comet is visible in the dawn sky 82 degrees west of the Sun at maximum brightness. This apparition favors the northern hemisphere. The comet will reach perihelion on December 29th, 2016 at 0.53 Astronomical Units (AU) from the Sun, and the comet passes just 0.08 AU (7.4 million miles) from the Earth on February 11th at 14:44 UT. The comet made a slightly closer pass in 2011, and was a fine binocular object that time around. At its closest, the comet will cross nine degrees of sky from one night to the next. Some notable dates for comet 45P/Honda-Mrkos-Pajdušáková are:
November 23rd: Venus passes 6′ from the comet.
December 12th: May break 10th magnitude.
December 14th: Passes near M75.
December 15th: Crosses into the constellation Capricornus.
January 4th: Passes near the +4th magnitude star Theta Capricorni
January 10th: Crosses the ecliptic northward.
January 16th: Passes into Aquarius.
January 22nd: Passes near NGC 7009, M72 and M73.
January 25th: Passes 8 degrees from the Sun and into the dawn sky.
January 28th: Crosses into Aquila.
February 3rd: Crosses the celestial equator northward.
February 4th: Passes 4′ from the star +3.3 magnitude star Delta Aquilae.
February 6th: Crosses the Galactic equator.
February 7th: Crosses into Ophiuchus.
February 9th: Crosses into Hercules.
February 16th: makes a wide pass near M3.
February 19th: Drops back below +10th magnitude.
This is the final close (less than 0.1 AU) passage of Comet 45P/Honda-Mrkos-Pajdušáková near the Earth for this century.
On July 1st 1770, Comet D/1770 L1 Lexell passed 0.0151AU from the Earth; a comet in 1491 may have passed closer. Next year’s passage of 45P/Honda-Mrkos-Pajdušáková ranks as the 21st closest passage of a comet near the Earth.
Why do comets end up with such cumbersome names? Well, comets derive their names from the first three discovers that submit the find within a 24 hour period to the Minor Planet Center’s Central Bereau for Astronomical Telegrams, which, in fact, received its last ‘telegram’ during the discovery of Comet Hale-Bopp around two decades ago. Increasingly, comets are receiving names of all sky surveys such as LINEAR and PanSTARRS from robotic competition against amateur hunters. It does seem like you need an umlaut or the chemical symbol for boron to in your moniker to qualify these days… rare is the ‘Comet Smith.’ But hey, it’s still fun to watch science journalists try and spell the Icelandic volcano Eyjafjallajökull and comet Churyumov-Gerasimenko over and over… Perhaps, we should insist that our first comet discovery is actually spelled Comet Dîckînsðn…
And Comet 45/P is just one of the fine binocular comets on deck for 2017. We’re also expecting Comet 41P/Tuttle-Giacobini-Kresák, 2/P Encke, C/2015 ER61 PanSTARRS Comet C/2015 V2 Johnson to break +10th magnitude next year… and the next great naked eye ‘Comet of the Century’ could light up the skies at any time.
Binoculars are the best tool to observe bright comets, as they allow you to simply sweep the star field and admire the full beauty of a comet, coma, tail(s) and all. Keep in mind, a comet will often appear visually fainter than its quoted brightness… this is because, like nebulae, that intrinsic magnitude is ‘smeared out’ over an extended area. To my eye, a binocular comet often looks like a fuzzy, unresolved globular cluster that stubbornly refuses to snap into focus.
Don’t miss your first looks at Comet 45/P 45P/Honda-Mrkos-Pajdušáková, as it spans 2016 into 2017.
Live in (or planning on visiting) the southern hemisphere soon? A first time visitor to the inner solar system is ready to put on the first of a two part act starting this month, as Comet C/2013 US10 Catalina breaks +10th magnitude and crosses southern hemisphere skies.
Discovered by the Catalina Sky Survey on Halloween 2013, the comet received its unusual ‘US10’ designation as it was initially thought to be an asteroid early on in a periodic six year orbit, until a longer observation arc was completed. This is not an unusual situation, as new objects are often lost in the Sun’s glare before their orbit can be refined.
We now know that US10 Catalina is on a million year long journey from the distant Oort Cloud. Most likely, it was disturbed by an unrecorded close stellar passage long ago. We say that such comets are dynamically new, and this passage will eject US10 Catalina from the solar system. The comet also has a highly inclined orbit tilted almost 149 degrees relative to the ecliptic, and was at +19th magnitude and 7.7 AU from the Earth when it was discovered, suggesting an intrinsically bright comet.
Prospects for US10 Catalina currently favor latitude 35 degrees north southward in late June, though that’ll change radically as the comet makes the plunge south this summer. As of this writing, US10 Catalina was at +11 magnitude ‘with a bullet’ and currently sits in the constellation Sculptor at a declination -30 degrees in the southern sky.
Binoculars are our favorite tools for observing comets, as they’ve easy to sweep the skies with on our cometary quest. As with nebulae and deep sky objects, keep in mind that quoted magnitude for a comet is spread out over its apparent surface area, causing them to appear fainter than a star of the same magnitude.
Here’s a blow-by-blow for Act I for Comet C/2013 US10 Catalina over the next few months:
(Unless otherwise noted, we documented stellar passages below that are within 2 degrees of stars brighter than +5th magnitude, and fine NGC deep sky objects brighter than +8th magnitude)
July 1st: May break binocular visibility, at +10th magnitude.
July 6th: Crosses into the constellation of Phoenix.
July 23rd: Crosses into the constellation Grus.
July 25th: Crosses into the constellation Tucana.
July 26th: Passes the +4th magnitude star Gamma Tucanae.
August 1st: Reaches opposition.
August 2nd: Passes the +4.5th magnitude star Delta Tucanae.
August 4th: Crosses into the constellation Indus.
August 6th: Photo op: Passes 12 degrees from 47 Tucanae and the Small Magellanic Cloud.
August 8th: Crosses into the constellation Pavo.
August 12th: Passes the +4th magnitude star Epsilon Pavonis.
August 14th: Reaches its greatest declination south at almost -74 degrees.
August 15th: Sits at 1.1 AU from the Earth.
August 17th: Crosses into the constellation Apus.
August 19th: Passes 5 degrees from the +7.7 magnitude globular cluster NGC 6362.
August 22nd: Crosses into the constellation Triangulum Australe and passes the +1.9 magnitude star Atria.
August 28th: Passes the +2.8 magnitude star Beta Trianguli Australis.
August 29th: Passes 3 degrees from the +5th magnitude open cluster NGC 6025.
September 1st: Crosses into the constellation Circinus
From there, Comet US10 Catalina heads towards perihelion 0.8229 astronomical units from the Sun on November 15th, before vaulting up into the northern hemisphere sky in the early dawn. Like Comet Q2 Lovejoy last winter, US10 Catalina should top out at around +4th magnitude or so as it glides across the constellation Ursa Major just after New Years.
And like many comets, the discriminating factor between a ‘great’ and ‘binocular comet’ this time around is simply a matter of orbital geometry. Had C/2013 US10 Catalina arrived at perihelion in the May time frame, it would’ve passed less than 0.2 AU (30 million kilometres) from the Earth!
But that’s cosmic irony for you. Keep in mind, with Comet US10 Catalina being a dynamically new first time visitor to the inner solar system, it may well up brighten ahead of expectations.
And there’s more to come… watch for Act II as we follow the continuing adventures of Comet C/2013 US10 Catalina this coming September!
Did you catch the performance of Comet C/2014 Q2 Lovejoy earlier this year? Every year provides a few sure bets and surprises when it comes to binocular comets, and while we may still be long overdue for the next truly ‘Great Comet,’ 2015 has been no exception.
This week, we’d like to turn your attention to two icy visitors to the inner solar system which may present the best bets comet-wise over the next few weeks: Comets C/2014 Q1 PanSTARRS and C/2015 G2 MASTER.
First up is Comet C/2014 Q1 PanSTARRS. Discovered on August 16, 2014 by the Panoramic Survey Telescope & Rapid Response System (PanSTARRS) based atop Mount Haleakala in Hawaii, we’ve known of the potential for Q1 PanSTARRS to put on a decent show this summer for a while. In fact, it made our roundup of comets to watch for in our 101 Astronomical Events for 2015. Q1 PanSTARRS currently sits at +11th magnitude as a morning sky object in the constellation Pisces. On a 39,000 year long parabolic orbit inclined 45 degrees relative to the Earth’s orbit, Q1 PanSTARRS will leap up across the ecliptic on May 17th and perhaps reach +3rd magnitude as it nears perihelion in early July and transitions to the evening sky.
Though it may put on its best show in July and August, a few caveats are in order. First, we’ll be looking at Q1 PanSTARRS beyond the summer Sun, and like C/2011 L4 PanSTARRS a few years back, it’ll never leave the dusk twilight, and will always appear against a low contrast backdrop.
Here are some notable upcoming events for Comet C/2014 Q1 PanSTARRS:
(Unless otherwise noted, a ‘close pass’ is here considered to be less than one degree of arc, about twice the diameter of a Full Moon.)
May 16: Passes into the constellation Aries.
May 16: The waning crescent Moon passes 2 degrees distant.
May 17: Crosses northward through the ecliptic.
May 20: May break +10th magnitude.
June 11: Passes in to the constellation Taurus.
June 12: Passes 2 degrees from M45 (The Pleiades).
June 15: May break 6th magnitude.
June 20: Passes into Perseus.
June 21: Passes into Auriga.
June 23: Passes +2.7 magnitude star Hassaleh (Iota Aurigae).
June 25: Passes the +7.5 magnitude open cluster IC 410.
June 26: Passes +6 magnitude Pinwheel Open Cluster (M36).
July 2: Crosses into Gemini.
July 3: Passes the +3.6 magnitude star Theta Geminorum.
July 5: Passes 10 degrees north of the Sun and into the evening sky.
July 6: Passes midway between Castor and Pollux.
July 6: Reaches perihelion at 0.315 astronomical units (AU) from the Sun.
July 7: May top out at +3rd magnitude.
July 8: Crosses into Cancer.
July 12: Photo Op: passes M44, the Beehive Cluster.
July 13: Sits 30 degrees from Comet C/2015 G2 MASTER (see below).
July 15: May drop below +6th magnitude.
July 15: Crosses the ecliptic southward.
July 17: The waxing crescent Moon passes 1.5 degrees south.
July 19: Crosses into Leo.
July 20: Closest to Earth, at 1.18 AU distant.
July 21: Less than 10 degrees from Jupiter and Venus.
July 22: Crosses into Sextans.
July 26: Crosses the celestial equator southward.
August 4: Crosses into Hydra.
August 5: Crosses into Crater.
August 18: Crosses back into Hydra.
August 30: Crosses into Centaurus.
September 1: Drops below +10th magnitude.
The next comet on deck is the recently discovered C/2015 G2 MASTER. If you live in the southern hemisphere, G2 MASTER is the comet that perhaps you haven’t heard of, but should be watching in the dawn sky. Discovered last month on April 7 as by MASTER-SAAO (The Russian built Mobile Astronomical System of Telescope-Robots at the South African Astronomical Observatory), this is not only the first comet bagged by MASTER, but the first comet discovery from South Africa since 1978. G2 MASTER has already reached magnitude +7 and is currently crossing the constellation Sculptor. It is also currently only visible in the dawn sky south of 15 degrees north latitude, but images already show a short spiky tail jutting out from G2 MASTER, and the comet may rival Q2 Lovejoy’s performance from earlier this year. Expect G2 MASTER to top out at magnitude +6 as it nears perihelion in mid-May. Observers around 30 degrees north latitude in the southern U.S. should get their first good looks at G2 MASTER in late May, as it vaults up past Sirius and breaks 10 degrees elevation in the evening sky after sunset. Again, as with Q1 PanSTARRS, cometary performance versus twilight will be key!
Here are some key dates with astronomical destiny for Comet G2 MASTER over the coming weeks:
May 9: Crosses into Fornax.
May 15: May top out at +6th magnitude.
May 13: Closest to Earth at 0.47 AU.
May 14: Crosses into Eridanus.
May 16: Crosses into Caelum.
May 17: Crosses into Lepus.
May 20: Passes the +3.8 magnitude star Delta Leporis.
May 23: Crosses into Canis Major.
May 23: Reaches perihelion at 0.8 AU from the Sun.
May 27: Crosses into Monoceros.
May 28: Passes the +5.9 magnitude Open Cluster M50.
June 8: Crosses northward over the celestial equator and into the constellation Canis Minor.
July 1: May drop below 10th magnitude.
G2 MASTER also crosses SOHO’s field of view on July 24th through August 4th, though it may be too faint to see at this point.
Here are the Moon phases for the coming weeks to aid you in your comet quest:
Full Moons: June 2nd, July 2nd, July 31st, August 29th.
New Moons: May 18th, June 16th, July 16th, August 14th.
Binoculars are our favorite ‘weapon of choice’ for comet hunting. Online, Heavens-Above is a great resource for quickly and simply generating a given comet’s sky position in right ascension and declination; we always check out the Comet Observers Database and Seiichi Yoshida’s Weekly Information about Bright Comets to see what these denizens of the outer solar system are currently up to.
Good luck, and be sure to regale us with your comet-hunting tales of tragedy and triumph!
As the Chinese proverb says, “May you live in interesting times,” and while the promise of Comet ISON dazzling observers didn’t exactly pan out as hoped for in early 2014, we now have a bevy of binocular comets set to grace evening skies for northern hemisphere observers. Comet 2012 K1 PanSTARRS has put on a fine show, and comet C/2014 E2 Jacques has emerged from behind the Sun and its close 0.085 AU passage near Venus and has already proven to be a fine target for astro-imagers. And we’ve got another icy visitor to the inner solar system beating tracks northward in the form of Comet C/2013 V5 Oukaimeden, and a grand cometary finale as comet A1 Siding Spring brushes past the planet Mars. That is, IF a spectacular naked eye comet doesn’t come by and steal the show, as happens every decade or so…
Anyhow, here’s a rapid fire run down on what you can expect from three of these binocular comets that continue to grace the twilight skies this Fall.
(Note that mentions of comets “passing near” a given object denote conjunctions of less than an angular degree of arc unless otherwise stated).
C/2014 E2 Jacques:
Discovered by amateur astronomer Cristovao Jacques on March 13th of this year from the SONEAR Observatory in Brazil, Comet E2 Jacques has been dazzling observers as it passed 35 degrees from the north celestial pole and posed near several deep sky wonders as it transited the constellation of Cassiopeia.
Mid-September finds Jacques 55 degrees above the NE horizon at dusk for northern hemisphere viewers in the constellation Cygnus. It then races southward parallel to the galactic equator, keeping in the +7th to +8th magnitude range before dropping down below +10th magnitude in late October. After this current passage through the inner solar system, Comet Jacques will be on a shortened 12,000 year orbit.
-Brightest: Mid-August at +6th magnitude.
-Perihelion: July 2nd, 2014 (0.66 AU).
-Closest to Earth: August 28, 2014 (0.56 AU).
Some key upcoming dates:
Sep 10: Passes the +3.9 magnitude star Eta Cygni.
Sep 14: Passes near the famous optical double star Albireo and crosses into the constellation of Vulpecula.
Sep 16: Passes in front of the +4.4 magnitude star Alpha Vulpeculae.
Sep 20: Crosses the Coathanger asterism.
Sep 21: Crosses into the constellation Sagitta.
Sep 24: Crosses into Aquila.
Oct 5: Crosses the galactic plane.
Oct 14: passes near the +7.5 magnitude open cluster NGC 6755.
Oct 15: Drops back below +10th magnitude?
C/2013 V5 Oukaïmeden
Pronounced Ow-KAY-E-Me-dah, (yes, it’s a French name, with a very metal umlaut over the “ï”!) comet C/2013 V5 Oukaïmeden was discovered by the Moroccan Oukaïmeden Sky Survey (MOSS) located in the Atlas Mountains in Morocco. After completing a brief dawn appearance in early September, the comet moves into the dusk sky and starts the month of October located 38 degrees east of the Sun at about 14 degrees above the southwestern horizon as seen from latitude 30 degrees north at sunset. Southern hemisphere observers will continue to have splendid dawn views of the comet through mid-September at its expected peak. Comet Oukaïmeden is currently at +8th magnitude “with a bullet” and is expected to top out +6th magnitude in late September shortly before perihelion and perhaps remain a binocular object as it crosses the constellation Libra in October.
And its also worth noting that as comet A1 Siding Spring (see below) makes a close physical pass by Mars on October 19th, Comet Oukaïmeden makes a close apparent pass by Saturn as seen from our Earthly vantage point the evening before! To be sure, the dusk apparition of Comet Oukaïmeden will be a tough one, but if you can track down these bright guidepost objects listed below, you’ll have a chance at spying it.
-Perihelion: September 28th, 2014 (0.63 AU from the Sun).
-Closest to Earth: September 16th, 2014 (0.48 AU).
Some key upcoming dates:
Sep 10 through Oct 4: Threads across the borders of the constellations Hydra, Pyxis, Antlia and Centaurus.
Sep 18: Passes near the +3.5 magnitude star Xi Hydrae.
Sep 19: Passes near the +4.3 magnitude star Beta Hydrae.
Sep 25: Passes 1.5 degrees from the +8th magnitude Southern Pinwheel Galaxy M83.
Oct 1: Passes in front of the +10.2 globular cluster NGC 5694.
Oct 3: Passes into Libra.
Oct 11: Passes near the +8.5 magnitude globular cluster NGC 5897.
Oct 16: Crosses the ecliptic plane northward.
Oct 18: Passes less than two degrees from Saturn.
Oct 25: Passes less than a degree from the 2 day old Moon and the +3.9 magnitude star Gamma Librae.
C/2013 A1 Siding Spring
This comet was discovered on January 3rd, 2013 from the Siding Spring observatory in Australia, and soon caught the eye of astronomers when it was discovered that it would make a nominal pass just 139,000 kilometres from Mars on October 19th.
As seen from the Earth, Comet A1 Siding Spring has just broken 10th magnitude and vaults up towards the planet Mars low to the southwest at dusk this Fall for northern hemisphere observers. A1 Siding Spring is expected to top out at +8th magnitude this month before its Mars encounter, and is on a one million year plus orbit.
-Brightest: Early to Mid-September.
-Perihelion: October 25th, 2014.
-Closest to Earth: October 28th, 2014 (1.4 AU).
Some key upcoming dates:
Sep 17: Passes into the constellation Telescopium.
Sep 20: Passes near the +8.5 magnitude globular NGC 6524.
Sep 21: Passes into the constellation Ara.
Sep 22: Passes the +3.6 magnitude star Beta Arae.
Sep 25: Crosses into Scorpius.
Sep 30: Passes the +3 magnitude star Iota Scorpii.
Oct 3: Passes near the +7.2 magnitude globular NGC 6441.
Oct 5: Passes 2 degrees from Ptolemy’s cluster M7.
Oct 8: Passes in front of the Butterfly cluster M6.
Oct 10: Crosses the galactic plane.
Oct 11: Crosses into Ophiuchus.
Oct 19: Passes just 2’ arc minutes from Mars as seen from Earth.
Oct 22: Passes north of the ecliptic.
Oct 30: Drops back below +10th magnitude?
Key moonless windows for evening comet viewing as reckoned from when the Moon wanes from Full to New are: September 9th to September 24th and October 8th to the 23rd.
Looking for resources to find out just what these comets and others are up to? The COBS Comet Observers database is a great resource for recent observations, as is Seiichi Yoshida’s Weekly Comet page. For history and current info, Gary Kronk’s Cometography is also a great treasure trove to delve into, as are the Yahoo! Comet and Comet Observer mailing lists.
Be sure to check out these fine icy visitors to the inner solar system coming to a sky near you. We fully expect to see more outstanding images of these comets and more filling up the Universe Today Flickr forum!
Get those binoculars ready: an icy interloper from the Oort cloud is about to grace the night sky.
The comet is C/2012 K1 PanSTARRS, and it’s currently just passed from the constellation Hercules into Corona Borealis and presents a good target for observers high in the sky in the hours before dawn. In fact, from our Tampa based latitude, K1 PanSTARRS is nearly at the zenith at around 6 AM local.
Observers currently place K1 PanSTARRS at magnitude +10.5 and brightening and showing a small condensed coma. Through the eyepiece, a comet at this stage will often resemble a fuzzy, unresolved globular star cluster.
And the good news is, K1 PanSTARRS will continue to brighten, headed northward through the early morning and then into the evening sky before reaching solar conjunction on August 9th, when it’ll actually pass behind the Sun for a few hours as seen from from our vantage point. We actually get two good apparitions of Comet K1 PanSTARRS: one for the northern hemisphere in the Spring and one for the southern hemisphere after it reaches perihelion and crosses south of the ecliptic plane in August.
And it’ll be worth keeping an eye out for K1 PanSTARRS online as well, as it passes into the view of SOHO’s LASCO C3 camera on August 2 before exiting its 15 degree field of view on August 16th.
This actually means the comet will reach opposition twice from our Earthbound vantage point: once on April 15th, and again on November 7th. And, as is often the case, this comet arrives six months early –or late, depending how you look at it- to be a fine naked eye object. Had K1 PanSTARRS reached perihelion in January, we’d have really been in for a show, with the comet only around 0.05 Astronomical Units (about 7.7 million kilometers) from the Earth!
But alas, such was not to be. At its best, K1 PanSTARRS will be hidden by the glare of the Sun at its very best, to emerge into the southern sky. The comet has a steeply inclined 142 degree retrograde orbit, and thus approaches the inner solar system from high above the ecliptic plane.
These coming last weeks of March are a great time to search out K1 PanSTARRS as the Moon reaches Last Quarter this weekend and heads towards New on March 30th, beginning a two week “moonless period for AM observing in early April. Projections by veteran comet observer Seiichi Yoshida suggest that K1 PanSTARRS will begin to brighten dramatically towards +8th magnitude through April. We first picked up the now posthumous comet ISON with binoculars around this magnitude last Fall. Keep in mind, like nebula and galaxies, the apparent brightness of a comet is spread out over its surface area. This can make a +10th magnitude comet much tougher to spot than a pinpoint +10 magnitude star.
We actually prefer our trusty Canon 15x45IS image stabilized binoculars for comet hunting… they’re powerful and easy to deploy on a cold March morning!
Here’s a handy list of notable events to watch for as Comet C/2012 K1 PanSTARRS crosses the springtime sky. Only passages of less than one degree near stars greater than magnitude +6 are mentioned except where otherwise noted:
March 17th: Comet C/2012 K1 PanSTARRS passes into the constellation Corona Borealis.
March 21st: Passes the +5.8 magnitude star Upsilon Coronae Borealis.
March 29th: Passes the +5.4 magnitude star Rho Coronae Borealis.
March 30th: The Moon reaches New phase.
April 2nd: Passes the +4.8 magnitude star Kappa Coronae Borealis.
April 7th: Passes the +5.2 magnitude star Mu Coronae Borealis.
April 10th: Passes into the constellation of Boötes.
April 10th: Passes the +5 magnitude wide binary pair Nu Boötis.
April 15th: Comet K1 PanSTARRS reaches opposition, rising opposite to the setting Sun and moving into the evening sky.
April 20th: K1 PanSTARRS becomes circumpolar for observers above 45 degrees north until May 25th.
April 26th: Passes into the constellation Ursa Majoris.
April 29th: Passes the bright +1.9th magnitude star Alkaid in the handle of the Big Dipper asterism. This is the brightest star that K1 PanSTARRS will pass near for this apparition, and Alkaid will make a great “finder” to spot the comet.
April 29th: The Moon reaches New phase.
April 30th: Approaches the +4.7 magnitude star 24 Canum Venaticorum.
May 1st: Passes less than 2 degrees from the galaxy M51… photo op!
May 3rd: Passes the 5.1 magnitude star 21 Canum Venaticorum.
May 6th: K1 PanSTARRS Reaches a maximum declination of 49.5 degrees north.
May 11th: Passes the 5.3 magnitude star 3 Canum Venaticorum.
May 14th: Passes into the constellation Ursa Major.
May 17th: Another great photo ops awaits astrophotographers, as the comet passes the +3.7 magnitude star Chi Ursae Majoris and the +12 magnitude galaxy NGC 3877.
May 25th: Passes the 3rd magnitude star Psi Ursae Majoris.
May 28th: The Moon reaches New phase.
May 28th: Passes the 4.7 magnitude star Omega Ursae Majoris.
June 7th Passes into the constellation Leo Minor.
June 15th: Passes the +4.5 magnitude star 21 Leo Minoris.
June 22nd: Passes into the constellation Leo.
July 1- Passes to within 40 degrees elongation from the Sun.
And from there, Comet K1 PanSTARRS reaches perihelion just outside of the Earth’s orbit at 1.05 A.U. on August 27, and plunges south across the celestial equator on September 15.
Video animation of comet C/2012 K1 PanSTARRS over the span of an evening. Credit: Dan Crowson of Dardenne Prairie Missouri, used with permission.
It’s also worth noting that K1 PanSTARRS will make its first of two approaches at a minimum distance of 1.471 A.U.s from Earth May 4th and will be moving at about a degree a day – twice the diameter of the Full Moon – before receding from us once more for a closer 1.056 A.U. approach to Earth on August 25th.
Discovered on May 19th, 2012 by the PanSTARRS telescope based on the island of Maui, Comet K1 PanSTARRS was first spotted at 8.7 A.U.s distant, well past the orbit of Jupiter. The PanSTARRS survey has been a prolific discoverer of asteroids and comets, including the brilliant comet C/2011 L4 PanSTARRS that graced dusk skies in March of last year.
And those are just the binocular comets that are scheduled to perform… remember, the next “big one” could come barreling in towards the inner solar system at any time to put on a memorable performance worthy of another comet Hyakutake or Hale-Bopp… just not TOO close!