Ready, Set, Messier Marathon: A 2014 Guide

Patiently awaiting darkness at the starting line... Credit and copyright: John Chumack.

Have YOU seen all 110?

The passage of the northward equinox last week on March 20th means one thing in the minds of many a backyard observer: the start of Messier Marathon season. This is a time of year during which a dedicated observer can conceivably spot all of the objects in Charles Messier’s famous deep sky catalog in the span of one night.

We’ve written about some tips and tricks to completing this challenge previously, as well as the optimal dates for carrying a marathon out. Typically, the New Moon weekend nearest the March equinox is the best time of year for northern hemisphere observers to target all of the objects on Messier’s list. This works because a majority of the Messier objects are clustered into two regions: towards the core of our galaxy in Sagittarius — where the Sun sits during the December solstice — up through the summer triangle constellations of Cygnus, Aquila and Lyra, and in the bowl of Virgo asterism and its super cluster of galaxies that extends northward into the constellation of Coma Berenices. In March through early April the Sun sits in the constellation of Pisces, well away from the galactic plane.

The prospects for completing a Messier marathon in 2014 favor the last weekend on March on the 29th-30th. The Moon reaches New on Sunday, March 30th at 18:45 Universal Time/2:45 PM EDT.

Messier marathons first came into vogue in the early 1970s right around the time Schmidt-Cassegrain and large Dobsonian “light bucket” telescopes came into general use.

Charles Messier began noting the curious objects that he would later incorporate into his famous catalog during the summer of 1758, with his description of the Crab Nebula in Taurus, which would become Messier object number one or M1. Messier was a prolific comet hunter and discovered 21 comets in his lifetime. The catalog was compiled over the span of 13 years from 1771 to 1784. Messier’s original list contained 45 objects, and was later expanded in subsequent editions 103, with Messier’s assistant Pierre Méchain adding six more objects to the catalog. The list is generally tallied at 110 objects, with one famous controversy being M102, which is generally cited as a re-observation of M101 or the galaxy NGC 5866.

The catalog itself contains a grab bag of open and globular clusters, galaxies, planetary and diffuse nebulae, and one double star (M40). The Messier catalog spans the sky down to M7, an object also known as the Ptolemy Cluster, which is the southernmost object on the list at latitude -34 degrees 48’ south.

The first page of Messier's third revision of his catalog describing M1 through M5. Image in th Public Domain.
The first page of Messier’s third revision of his catalog, describing M1 through M5. Image in the Public Domain.

Messier observed from Paris at latitude +48 degrees 51’ north using two primary telescopes of the almost one dozen that he owned for his discoveries: a 6.4” Gregorian reflector and a 3.5” refractor. Messier knew nothing of the nature of these “faint fuzzies” that he’d periodically stumbled across in his cometary vigil. His original intent was to compile a list of “comet imposters” in the night sky for comet hunters to be aware of in their quests. In his words:

“What made me produce this catalog was the nebula which I had seen in Taurus while I was observing the comet of that year (1758). The shape and brightness of that nebula reminded me so much of a comet, that I undertook to find more of its kind, to save astronomers from confusing these nebulae with comets.”

“Beware, here doth not lie comets,” Messier admonishes future generations of observers. Still, some peculiarities remain in the catalog: why did Messier, for example, include such obvious “non-comets” as the Pleiades (M45), but skip over the brilliant Double Cluster in Perseus?

Charles Messier's 1771 sketch of the Orion nebula, M42 in the Messier Catalog. Image in the public domain.
Charles Messier’s 1771 sketch of the Orion nebula, M42 in the Messier Catalog. Image in the public domain.

Alas, such mysteries are known only to Messier, who was interred at the famous Père Lachaise cemetery after his death in 1817. When we visit Paris, we’ll bypass Jim Morison to leave a copy of Burnham’s Celestial Handbook at Messier’s grave.

And just like the road variety, “running the Messier marathon” takes all of the stamina and pacing that a visual athlete can muster. You’ll want to grab M77 and M74 immediately after dusk, or the marathon will be over before it starts. From there, move on up north to the famous Andromeda galaxy (M31) and the scattering of objects around it before settling in for a more leisurely observing pace moving westward through the constellations of Orion, Leo and surrounding objects.

An all-sky map showing the distribution of Messier objects. (Click to enlarge). Credit: Jim Cornmell under a Wikimedia Commons Attribution-Share Alike 3.0 Unported license.
An all-sky map showing the distribution of Messier objects. (Click to enlarge). Credit: Jim Cornmell under a Wikimedia Commons Attribution-Share Alike 3.0 Unported license.

Now towards the approach of local midnight comes the first large group: the Virgo cluster of galaxies extending through Coma Berenices, rising to the east. After this batch, you can catch some quick shut-eye before bagging the Messier objects towards the galactic center and up through Cygnus in the pre-dawn. Plan ahead; M52, M2 and M30 are especially notoriously difficult in the spring dawn sky!

It’s also worth noting your “attitude versus latitude” plays a role as well. To this end, Ed Kotapish compiled this nifty perpetual chart of when the entire Messier catalog is visible from respective latitudes:

A chart calculating number of total Messier objects that are visible on the dates (vertical column in month-day format) versus north latitude (top row). Note that this chart is pertpetual for non-leap years, and does not take into account the pahse of the Moon. Click to enlarge. Credit: Edward Kotapish.
A chart calculating number of total Messier objects that are visible on the dates (vertical column in month-day format) versus north latitude (top row). Note that this chart is pertpetual for non-leap years, and does not take into account the pahse of the Moon. Click to enlarge. Credit: Edward Kotapish.

“The bounds of the chart are for a variety of objects,” Ed told Universe Today. “I used nautical twilight (when the Sun falls below -12 degrees in elevation) as the starting and ending condition.” Ed also notes that the top curve of the chart on the morning side is bounded by the difficulty in finding troublesome M30, while the left bottom evening boundary is limited by the observability of M110 and M74, which can be a problem for observers at higher latitudes.

Alternate versions of the Messier marathon exist as well, such as imaging or even sketching all 110 objects in one night.

Why complete a Messier marathon? Well, not only does such a feat hone your visual skills as an observer, but it also familiarizes you with the entire catalog… and there’s nothing that says you have to complete it all in one evening, except of course, for bragging rights at the next star party!

Good luck!

-Here’s a handy list of all 110 of the Messier objects in the catalog.

-Be sure to send those pics of Messier objects and more in to Universe Today’s Flickr forum!

Get Set For Comet K1 PanSTARRS: A Guide to its Spring Appearance

Comet c/2012 K1 PanSTARRS as imaged by Dan Crowson on February 22nd, 2014. Image credit: Dan Crowson, used with permission.

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!

The orbit of comet K1 PanSTARRS.
The orbit of comet K1 PanSTARRS through the inner solar system. The yellow arrows denote the motion of the planets and the comet as seen from north of the ecliptic plane. Credit-NASA/JPL Horizons Solar System Dynamics generator.

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.

The path of comet K1 PanSTARRS through March and April
The path of comet K1 PanSTARRS in one week intervals through March and April. Created using Stellarium.

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.

Path of comet K1 PanSTARRS Credit: Starry Night Education Software
The Spring path of comet K1 PanSTARRS from mid-March through late June. Credit: Starry Night Education Software.

May 1st: Passes into the constellation Canes Venatici.

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.

Comet K1 PanSTARRS will join the ranks of comets reaching binocular observability later this year which includes C/2013 V5 Oukaimeden, Comet C/2013 A1 Siding Spring, and the recently discovered C/2014 E2 Jacques, which may reach +7th magnitude as it nears perihelion this coming July.

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!

–      Be sure to send those comet pics in to Universe Today.

“Death Stars” Caught Blasting Proto-Planets

Credit

 It’s a tough old universe out there. A young star has lots to worry about, as massive stars just beginning to shine can fill a stellar nursery with a gale of solar wind.

No, it’s not a B-movie flick: the “Death Stars of Orion” are real. Such monsters come in the form of young, O-type stars.

And now, for the first time, a team of astronomers from Canada and the United States have caught such stars in the act. The study, published in this month’s edition of The Astrophysical Journal, focused on known protoplanetary disks discovered by the Hubble Space Telescope in the Orion Nebula.

These protoplanetary disks, also known as “tadpoles” or proplyds, are cocoons of dust and gas hosting stars just beginning to shine. Much of this leftover material will go on to aggregate into planets, but nearby massive O-Type stars can cause chaos in a stellar nursery, often disrupting the process.

“O-Type stars, which are really monsters compared to our Sun, emit tremendous amounts of ultraviolet radiation and this can play havoc during the development of young planetary systems,” said astronomer Rita Mann in a recent press release. Mann works for the National Research Council of Canada in Victoria and is  lead researcher on the project 

Scientists used the Atacama Large Millimeter Array (ALMA) to probe the proplyds of Orion in unprecedented detail.  Supporting observations were also made using the Submillimeter Array in Hawaii.

ALMA saw “first light” in 2011, and has already achieved some first rate results.

“ALMA is the world’s most sensitive telescope at high-frequency radio waves (e.g., 100-1000 GHz). Even with only a fraction of its final number of antennas, (with 22 operational out of a total planned 50) we were able to detect with ALMA the disks relatively close to the O-star while previous observatories were unable to spot them,” James Di Francesco of the National Research Council of Canada told Universe Today. “Since the brightness of a disk at these frequencies is proportional to its mass, these detections meant we could measure the masses of the disks and see for sure that they were abnormally low close to the O-type star.”

Credit
The ALMA antennae on the barren plateau of Chajnantor. Credit: ALMA (ESO/NAOJ/NRAO).

ALMA also doubled the number of proplyds seen in the region, and was also able to peer within these cocoons and take direct mass measurements. This revealed mass being stripped away by the ultraviolet wind from the suspect O-type stars. Hubble had been witness to such stripping action previous, but ALMA was able to measure the mass within the disks directly for the first time.

And what was discovered doesn’t bode well for planetary formation. Such protostars within about 0.1 light-years of an O-type star are consigned to have their cocoon of gas and dust stripped clean in just a few million years, just a blink of a eye in the game of planetary formation.

With a O-type star’s “burn brightly and die young” credo, this type of event may be fairly typical in nebulae during early star formation.

“O-type stars have relatively short lifespan, say around 1 million years for the brightest O-star in Orion – which is 40 times the mass of our Sun – compared to the 10 billion year lifespan of less massive stars like our Sun,” Di Francesco told Universe Today. “Since these clusters are typically the only places where O-stars form, I’d say that this type of event is indeed typical in nebulae hosting early star formation.”

It’s common for new-born stars to be within close proximity of each other in such stellar nurseries as M42. Researchers in the study found that any proplyds within the extreme-UV envelope of a massive star would have its disk shredded in short order, retaining on average less than 50% the mass of Jupiter total. Beyond the 0.1 light year “kill radius,” however, the chances for these proplyds to retain mass goes up, with researchers observing anywhere from 1 to 80 Jupiter masses of material remaining.

The findings in this study are also crucial in understanding what the early lives of stars are like, and perhaps the pedigree of our own solar system, as well as how common – or rare – our own history might be in the story of the universe.

There’s evidence that our solar system may have been witness to one or more nearby supernovae early in its life, as evidenced by isotopic measurements. We were somewhat lucky to have had such nearby events to “salt” our environment with heavy elements, but not sweep us clean altogether.

“Our own Sun likely formed in a clustered environment similar to that of Orion, so it’s a good thing we didn’t form too close to the O-stars in its parent nebula,” Di Francesco told Universe Today. “When the Sun was very young, it was close enough to a high-mass star so that when it blew up (went supernova) the proto-solar system was seeded with certain isotopes like Al-26 that are only produced in supernova events.”

This is the eventual fate of massive O-type stars in the Orion Nebula, though none of them are old enough yet to explode in this fashion. Indeed, it’s amazing to think that peering into the Orion Nebula, we’re witnessing a drama similar to what gave birth to our Sun and solar system, billions of years ago.

The Orion Nebula is the closest active star forming region to us at about 1,500 light years distant and is just visible to the naked eye as a fuzzy patch in the pommel of the “sword” of Orion the Hunter. Looking at the Orion Nebula at low power through a small telescope, you can just make out a group of four stars known collectively as the Trapezium. These are just such massive hot and luminous O-Type stars, clearing out their local neighborhoods and lighting up the interior of the nebula like a Chinese lantern.

And thus science fact imitates fiction in an ironic twist, as it turns out that “Death Stars” do indeed blast planets – or at least protoplanetary disks – on occasion!

Be sure to check out a great piece on ALMA on a recent episode of CBS 60 Minutes:

Read the abstract and the full (paywalled) paper on ALMA Observations of the Orion Proplyds in The Astrophysical Journal.

Astronomers Identify the Largest Yellow “Hypergiant” Star Known

Credit: ESO

A stellar monster lurks in heart of the Centaur.

A recent analysis of a star in the south hemisphere constellation of Centaurus has highlighted the role that amateurs play in assisting with professional discoveries in astronomy.

The find used of the European Southern Observatory’s Very Large Telescope based in the Atacama Desert in northern Chile — as well as data from observatories around the world — to reveal the nature of a massive yellow “hypergiant” star as one of the largest stars known.

The stats for the star are impressive indeed: dubbed HR 5171 A, the binary system weighs in at a combined 39 solar masses, has a radius of over 1,300 times that of our Sun, and is a million times as luminous. Located 3,600 parsecs or over 11,700 light years distant, the star is 50% larger than the famous red giant Betelgeuse. Plop HR 5171 A down into the center of our own solar system, and it would extend out over 6 astronomical units (A.U.s) past the orbit of Jupiter.

The field around HR 5171 A (the brightest star just below center). Credit: ESO/Digitized Sky Survey 2.
The field around HR 5171 A (the brightest star just below center). Credit: ESO/Digitized Sky Survey 2.

Researchers used observations going back over 60 years – some of which were collected by dedicated amateur astronomers – to pin down the nature of this curious star. A variable star just below naked eye visibility spanning a magnitude range from +6.1 to +7.3, HR 5171 A also has a relatively small companion star orbiting across our line of sight once every 1300 days. Such a system is known as an eclipsing binary. Famous examples of similar systems are the star Algol (Alpha Persei), Epsilon Aurigae and Beta Lyrae. The companion star for HR 5171 is also a large star in its own right at around six solar masses and 400 solar radii in size. The distance from center-to-center for the system is about 10 A.U.s – the distance from Sol to Saturn – and the surface-to-surface distance for the A and B components of the system are “only” about 2.8 A.U.s apart. This all means that these two massive stars are in physical contact, with the expanded outer atmosphere of the bloated primary contacting the secondary, giving the pair a distorted peanut shape.

“The companion we have found is very significant as it can have an influence on the fate of HR 5171 A, for example stripping off its outer layers and modifying its evolution,” said astronomer Olivier Chesneau of the Observatoire de la Côte d’Azur in Nice France in the recent press release.

Knowing the orbital period of a secondary star offers a method to measure the mass of the primary using good old Newtonian mechanics. Coupled with astrometry used to measure its tiny parallax, this allows astronomers to pin down HR 5171 A’s stupendous size and distance.

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Along with luminous blue variables, yellow hypergiants are some of the brightest stars known, with an absolute magnitude of around -9. That’s just 16x times fainter than the apparent visual magnitude of a Full Moon but over 100 times brighter than Venus – if you placed a star like HR 5171 A 32 light years from the Earth, it would easily cast a shadow.

Astronomers used a technique known as interferormetry to study HR 5171 A, which involves linking up several telescopes to create the resolving power of one huge telescope. Researchers also culled through over a decade’s worth data to analyze the star. Though much of what had been collected by the American Association of Variable Star Observers (the AAVSO) had been considered to be too noisy for the purposes of this study, a dataset built from 2000 to 2013 by amateur astronomer Sebastian Otero was of excellent quality and provided a good verification for the VLT data.

The discovery is also crucial as researchers have come to realize that we’re catching HR 5171 A at an exceptional phase in its life. The star has been getting larger and cooling as it grows, and this change can be seen just over the past 40 year span of observations, a rarity in stellar astronomy.

“It’s not a surprise that yellow hypergiants are very instable and lose a lot of mass,” Chesneau told Universe Today. “But the discovery of a companion around such a bright star was a big surprise since any ‘normal’ star should at least be 10,000 times fainter than the hypergiant. Moreover, the hypergiant was much bigger than expected. What we see is not the companion itself, but the regions gravitationally controlled and filled by the wind from the hypergiant. This is a perfect example of the so-called Roche model. This is the first time that such a useful and important model has really been imaged. This hypergiant exemplifies a famous concept!”

Indeed, you can see just such photometric variations as the secondary orbits its host in the VLTI data collected by the AMBER interferometer, backed up by observations from GEMINI’s NICI chronograph:

Credit: ESO/VLT/GEMINI/NICI
Looking at the bizarre system of HR 5171. Credit: Olivier Chesneau/ESO/VLT/GEMINI/NICI

The NIGHTFALL program was also used for modeling the eclipsing binary components.

These latest measurements place HR 5171 A firmly in the “Top 10” for largest stars in terms of size known, as well as the largest yellow hypergiant star known This is due mainly to tidal interactions with its companion. Only eight yellow hypergiants have been identified in our Milky Way galaxy.  HR 5171 A is also in a crucial transition phase from a red hypergiant to becoming a luminous blue variable or perhaps even a Wolf-Rayet type star, and will eventually end its life as a supernova.

Enormous stars:
Enormous stars: From left to right, The Pistol Star, Rho Cassiopeiae, Betelgeuse and VY Canis Majoris compared with the orbits of Jupiter (in red) and Neptune (in blue). Remember, HR 5171 A is 50% larger than Betelgeuse! Credit: Anynobody under a Creative Commons Attribution Share-Alike 3.0 Unported license.

HR 5171 A is also known as HD 119796, HIP 67261, and V766 Centauri. Located at Right Ascension 13 Hours 47’ 11” and declination -62 degrees 35’ 23,” HR 5171 culminates just two degrees above the southern horizon at local midnight as seen from Miami in late March.

Credit: Stellarium
HR 5171 A: a finder chart. Click to enlarge. Credit: Stellarium

HR 5171 A is a fine binocular object for southern hemisphere observers.

But the good news is, there’s another yellow hypergiant visible for northern hemisphere observers named Rho Cassiopeiae:

Credit: Stellarium
The location of Rho Cassiopeiae in the night sky. Credit: Stellarium

Rho Cass is one of the few naked eye examples of a yellow hypergiant star, and varies from magnitude +4.1 to +6.2 over an irregular period.

It’s amusing read the Burnham’s Celestial Handbook entry on Rho Cass. He notes the lack of parallax and the spectral measurements of the day — the early 1960s — as eluding to a massive star with a “true distance… close to 3,000 light years!” Today we know that Rho Cassiopeiae actually lies farther still, at over 8,000 light years distant. Robert Burnham would’ve been impressed even more by the amazing nature of HR 5171 as revealed today by ESO astronomers!

–      The AAVSO is always seeking observations from amateur astronomers of variable stars.

How to Watch an Asteroid Occult a Bright Star on March 20th

Credit-IOTA

 Live in the New York City tri-state area, or anywhere near the path above? One of the most unusual big ticket astronomical events of 2014 occurs on in the morning hours of Thursday March 20th, when the asteriod 163 Erigone “blocks” or occults the bright star Regulus.

This is brightest star to be occulted by an asteroid for 2014, and has a potential to be observed by millions.

Occultations of stars by asteroids are often elusive events, involving faint stars and often occurring over remote locales. Not so with this one. In fact, the occultation of Regulus on March 20th will result in an “asteroid shadow” passing over viewers across the populous areas of New York and adjoining states in the U.S. northeast before racing into Canada.

And unlike most asteroid occultations, you won’t need any special equipment to detect this event. Shining at magnitude +1.3, Regulus is an easy and familiar naked eye object and is the 22nd brightest star in the sky. And heck, it might be interesting just to catch a view of the constellation Leo minus its brightest star!

Credit: Stellarium
Finding Regulus: Looking westward from the New York tri-state region at the time of the occultation. Credit: Stellarium.

Asteroid 163 Erigone shines at magnitude+12.4 during the event. At 72 kilometres in diameter and 1.183 A.U.s distant during the occultation, 163 Erigone was discovered by French astronomer Henri Joseph Perrotin on April 26th, 1876.

There’s a great potential to learn more not only about 163 Erigone during the event, but Regulus itself. Amateur observations will play a key role in this effort. The International Occultation Timing Association (IOTA) seeks observations from this and hundreds of events that occur each year. Not only can such a precise measurement help to pin down an asteroid’s orbit, but precise timing of the occultation can also paint a “picture” of the profile of the asteroid itself.

Example credit:
An example of an asteroid shape profile created by observers during the occultation of a star by asteroid 55 Pandora in 2007. Each cord represents an observer. Credit- The IOTA.

Regulus also has a faint white dwarf companion, and it’s just possible that it may be spied a fraction of a second before or after the event.   Does 163 Erigone have a moon? Several asteroids are now known to possess moons of their own, and it’s just possible that 163 Erigone could have a tiny unseen companion, the presence of which would be revealed by a small secondary event. Observers along and outside the track from Nova Scotia down to Kentucky are urged to be vigilant for just such a surprise occurrence:

Wide map (credit)
A widened map of the March 20th event, noting the span over which an unseen “moon” of 163 Erigone could be potentially observed. Credit: IOTA/Ted Blank/Google Earth.

The maximum duration for the event along the centerline is 14.3 seconds, and the rank for the event stands at 99%, meaning the path is pretty certain.

The shadow touches down on Earth in the mid-Atlantic at 5:53 Universal Time (UT), and grazes the island of Bermuda before making landfall over Long Island New York, New Jersey, Connecticut and northeastern Pennsylvania just after 6:06 UT/2:06 AM EDT. From there, the shadow of the asteroid heads to the northwest and crosses Lake Ontario into Canada before passing between the cities of Ottawa and Toronto just before 6:08 UT. Finally, it crosses out over Hudson Bay and Nunavut before departing the surface of our fair planet at 6:22 UT.

The path is about 117 kilometres wide, and the “shadow” races across the surface of the Earth at about 2.8 kilometres per second from the southeast to the northwest.

Credit: IOTA
A technical map including the specifics for the March 20th occultation of Regulus. Click to enlarge. Credit: The IOTA.

Timing an occultation can be accomplished via audio or video recording, though accurate time is crucial for a meaningful scientific observation. The IOTA has a complete explanation of tried and true methods to use for capturing and reporting the event.

We had a chance to catch up with veteran asteroid occultation observer Ted Blank concerning the event and the large unprecedented effort underway to capture it.

He notes that Regulus stands as the brightest star that has been observed to have been occulted by an asteroid thus far when 166 Rhodope passed briefly in front of it on October 19th, 2005.

“This is the best and brightest occultation ever predicted to occur over a populated area, and that covers the entire 40 years of predictive efforts,” Mr. Blank told Universe Today concerning the upcoming March 20th event.

The general public can participate in the scientific effort for observations as well.

“We’re trying to make a “picket fence” of thousands of observers to catch this asteroid, so the best thing to do is to go out and observe. If they live anywhere near or in the path, just step outside (or watch from a warm house through a window). Make sure they are looking at the right star,” Mr. Blank told Universe Today.  “If they can travel an hour or so to be somewhere in the predicted path, by all means do so – they’ll be home and back in bed well before rush hour starts! Then report what they saw at the public reporting page. If no occultation was seen, report a miss. This is more important that people think, since “miss” observations define the edges of the asteroid.”

There is also a handy “Occultation 1.0” timing app now available for IPhone users for use during the event.

Mr. Blank also plans to webcast the occultation live via UStream, and urges people to check the Regulus2014 Facebook page for updates on the broadcast status, as well as the final regional weather prospects leading up event next week. For dedicated occultation chasers, mobility and the ability to change observing locale at the last moment if necessary may prove key to nabbing this one. One of our preferred sites to check the cloud cover forecast prior to observing any event is the Clear Sky Chart.

This promises to be a historic astronomical event. Thanks to Ted Blank and Brad Timerson at the IOTA for putting the public outreach project together for this one, and be sure not to miss the occultation of Regulus on March 20th!

Watch a Bright Star Disappear Behind the Moon Monday Night

Lambda Geminorum at 10:43 p.m. March 11 just two minutes before disappearing behind the moon as seen from Minneapolis, Minn. US. Stellarium

Ever dabbled in the occult? You’ll have your chance Monday night March 10 when the waxing gibbous moon glides in front of the star Lambda Geminorum for much of North America, occulting it from view for an hour or more. Occultations of stars by the moon happens regularly but most go unnoticed by casual skywatchers. Lambda is an exception because it’s one of the brighter stars that happens to lie along the moon’s path. Shining at magnitude +3.6, any small telescope and even a pair of 10×50 or larger binoculars will show it disappear along the dark edge of the moon. 

Map showing where the occulation of Lambda Gem will be visible. Credit: International Occultation Timing Assn. (IOTA)
Map showing where the disappearance (right half of tube-like figure) and reappearance of Lambda Gem will be visible. Credit: International Occultation Timing Assn. (IOTA)

With a telescope you can comfortably watch the star creep up to the moon’s edge and better anticipate the moment of its disappearance. The fun starts a few minutes before the impending black out when the moon, speeding along its orbit at some 2,280 mph (3,700 km/hr),  draws very close to the star. During the final minute, Lambda may seem to hover forever at the moon’s invisible dark limb, and then – PFFFT – it’s gone! Whether you’re looking through telescope or binoculars, the star will blink out with surprising suddenness because the moon lacks an atmosphere.

Disappearance and reappearance seen from Minneapolis, Minn. Monday night. I've lightened the moon so you can see the dark limb. You'll likely not see this edge in a telescope because of glare. Stellarium
Disappearance and reappearance seen from Minneapolis, Minn. Monday night. I’ve lightened the moon so you can see the dark limb. You’ll likely not see this edge in a telescope because of glare. Stellarium

If there was air up there, Lambda would gradually dim and disappear. Even without special instruments, early astronomers could be certain the moon had little if anything to protect it from the vacuum of space by observing occultations.

As the moon moves approximately its own diameter in an hour, you can watch Lambda re-emerge along the bright limb roughly an hour later, though its return will lack the drama and contrast of a dark limb disappearance. While occultations allow us to see how swiftly the moon moves in real time as well as provide information on its atmosphere or lack thereof, real science can be done, too.


Planets also are occasionally occulted by the moon. Time lapse of Venus’ disappearance on May 16, 2010

Observers along the occultation boundary in the southern U.S. can watch the star pop in and out of view as it’s alternately covered and uncovered by lunar peaks jutting from the moon’s limb. Before spacecraft thoroughly mapped the moon, careful timings made during these “grazing occultations” helped astronomers refine the profile of the moon’s limb as well as determine elevations of peaks and crater walls in polar regions. They can still be useful for refining a star’s position and motion in the sky.

The moon’s limb can also be used much like a doctor’s scalpel  to split unsuspected  double stars that otherwise can’t be resolved by direct observations. Take Lambda Gem for instance. We’ve known for a long time that it totes around a magnitude +10.7 companion star 10 arc seconds to its north-northeast,  but previous occultations of the star have revealed an additional companion only a few hundredths of an arc second away orbiting the bright Lambda primary. The star plays a game of hide-and-seek, visible during some occultations but not others. Estimated by some as one magnitude fainter than Lambda, keep an eye out for it Monday night in the instant after Lambda goes into hiding.


Lunar occultation and reappearance of Antares Oct. 21, 2009

I watched just such a  “two-step” disappearance of Antares and it fainter companion some years back. With brilliant Antares briefly out of view behind the moon’s limb, I easily spotted its magnitude +5.4 companion just 2.5 arc seconds away – an otherwise very difficult feat at my northern latitude.

Want to know more about things that disappear (and reappear) in the night? Make a visit to the International Occultation Timing Association’s website where you’ll find lists of upcoming events, software and how to contribute your observations. If you’re game for Monday night’s occultation, click HERE for a list of cities and times. Remember that the time show is Universal or Greenwich Time. Subtract 4 hours for Eastern Daylight, 5 for Central, 6 for Mountain and 7 for Pacific.  Wishing you clear skies as always!

See Light Pollution in Action

Like anyone else who’s ever looked up at the night sky in any but the smallest cities, I’ve seen light pollution first-hand. Like anyone else even marginally involved in amateur astronomy, I know about the fight against light pollution. And I know that, what with new LED lights and everything, it’s not going to be easy.

When, the other day, I was looking around for images demonstrating the effects of light pollution, it didn’t take me long to find some scary examples – the satellite images tracing human presence on Earth by its light pollution are rather unequivocal, and on Wikimedia Commons, there was an impressive image showing the same region of the night sky when viewed from a dark and from a lighter location:


The images were taken by Jeremy Stanley and are available via Wikimedia Commons under the CC BY 2.0 license. According to the author’s comment, he tried to match the two images’ sky brightness to his memory of how bright the sky appeared to his eyes.

What I didn’t find was an image showing a comparison of two images with the same specs (same camera and lens, same ISO, aperture and exposure time) under different viewing conditions. In the end, I found that I could produce such an example myself, using images I had taken during a trip to South Africa last spring.

During the first leg of our trip, we had visited South Africa’s national science festival, SciFest Africa, which is held annually in Grahamstown in the Eastern Cape Province. Grahamstown has a population of 70.000, and there is some visible light pollution. I took an image of the Milky Way, including the Southern Cross, from the reasonably well-lit courtyard of our hotel:

IMG_4954

Some days later, we visited the Sutherland site of South Africa’s National Observatory SAAO, home, among other things, to the 10 m South African Large Telescope (SALT). In the small city of Sutherland, with a population of only about 3000, the observatory a mere 7 miles away and a spirit of cooperation with the astronomers’ needs, light pollution levels are low.

When we took some images of the sky from the backyard of our hotel, the biggest light pollution problem was the moon. Here’s an image that shows, among other objects, the Southern Cross, Alpha Centauri and Carina:

IMG_5416

It was only much later that I realized that these images could be used for the light pollution comparison I was looking for. They were both taken with the same camera (Canon EOS 450D = EOS Rebel XSi), the same lens (Tokina 11-16 mm at 11 mm) with the same settings (ISO 1600, aperture 2.8, exposure time 10 seconds). Whatever difference you see is really due to the viewing conditions. To show what you can do with a dark, high-contrast sky, I added a third image. Its only difference to the second image is the exposure time (20 seconds to 10 seconds), which brings out the Milky Way much more strongly.

I combined the images, used GIMP to increase the contrast and saturation on the combined image (to make sure I treated all three images the same), and separated the images again. Here is the result:

top

middle

bottom

The difference between the first two images is fairly drastic. And keep in mind that, as far as light pollution goes, Grahamstown is likely to be fairly harmless, compared with a big, brightly-lit city. (And yes, if I should get the chance, I’ll try to take an image with the same set-up in a larger city!)

This is just one of all too many examples. Through careless lighting, many of us are missing out on one of humanity’s most fundamental experiences: an unobstructed view of the enormity of what’s out there, far beyond space-ship Earth.

Daylight Saving Time: A Spring Forward or a Step Back?

The tricky business of keeping time... the Astronomical Clock in Prague, Czech Republic.

 The time to change clocks is once again nigh.

We’ll put our unabashed bias as a lover of the night sky right up front: we loathe Daylight Saving Time. And it’s not just because of the biannual hunt through our home for the dozen-odd non-networked clocks that it instigates twice a year. For astronomers, the shift to DST means that true darkness falls much later in the evening, marking the abrupt end of the school star party season not long after March. You don’t have to go far north to about latitude 45 degrees to find areas where it doesn’t get dark until about 11PM local towards mid-summer. And sure, we gain back an extra hour of morning darkness, albeit that too soon dwindles towards summer as well.

In 2014 we (as in a majority of North America) spring forward one hour on March 9th at 2:00 AM local. That’s just one day shy of the earliest that we can now spring forward, as the current convention established by the Energy Policy Act of 2005 during the Bush administration that was enacted in 2007 now sets the beginning of DST as the 2nd Sunday in March.

We’re now on DST for about roughly eight months or 67% of the calendar year. The European Union still shifts forward on the last Sunday of March, meaning that for a span of three weeks every March, the time lag between, say, Eastern Daylight Time and British Standard Time closes briefly to four hours before opening up again to five hours.

Current DST usage worldwide. Regions in blue currently use DST, orange have scrapped DST, and regions in red have never used DST. Credit: Paul Eggert under a wikimedia Creative Commons Attribution-Share Alike 3.0 Unported license.
Current DST usage worldwide. Regions in blue currently use DST, orange have scrapped DST, and regions in red have never used DST. Credit: Paul Eggert under a Wikimedia Creative Commons Attribution-Share Alike 3.0 Unported license.

And that’s just for starters.

Of course, there are holdouts even among DST observing countries worldwide. The states of Arizona and Hawaii do not observe DST, nor did a portion of Indiana until 2006. When DST is in effect, you can touch on three time zones in just a few hours’ drive from southeastern Arizona crossing southern New Mexico and into Texas east of El Paso. And you can really mix things up driving across the Navajo nation in northeastern Arizona – which observes DST, unlike the rest of the state – into the Hopi Reservation embedded within it, which rejects DST.

In Canada, most of Saskatchewan ignores DST, as do small portions of British Columbia, Quebec and Nunavut. In 2011, Russia opted to remain on Daylight Saving Time year round, and Australia is sharply divided on the issue of keeping DST. Of course, in the southern hemisphere, astronomical spring and fall are reversed, making UK/US/Australia teleconference scheduling even more confusing this time of year, not to mention the often bewildering state of affairs faced by computer programmers seeking to include every new rule and nuisance concerning local timekeeping worldwide.

1918 Poster espousing the benifits of the first DST shift for the U.S. Credit: U.S. Library of Congress image in the Public Domain.
1918 Poster espousing the benefits of the first DST shift for the U.S. Credit: U.S. Library of Congress image in the Public Domain.

Most folks trace the notion of daylight saving time back to Benjamin Franklin, though DST saw its first implementation by Axis powers in 1916 as a cost saving measure. In the United States, the Standard Time Act of 1918 put DST into effect for the first time, and it was an on again, off again affair through most of the 20th century.

And it’s not just your imagination: we do spring forward earlier and fall back later in the year than we used to. The Uniform Time Act was amended in 1986 to begin DST on the first Sunday in April and run until the last Sunday in October. And as mentioned previously, the Energy Policy Act of 2005 modified this even further under President George W. Bush to our present state of affairs, starting DST on the second Sunday of March through the first Sunday in November.

The primary rational behind DST use is to cut energy consumption. Studies done by the U.S. Department of Transportation during the adoption of DST during the 1970’s OPEC Oil Embargo and the energy crisis showed a small but measurable net savings during the implementation of DST, as well as a small decrease in the crime rate. On the down side, many find it difficult to adjust their body clocks to the shift, with many morning commuters now confronted with darkness.

Is DST a conspiracy of the golf crowd and/or the candy lobby? Anecdotal tales abound that some senators simply wanted few more hours on the course each evening, and “Big Sugar” (a great pro-wrestling name, BTW) was all too willing to oblige. Certainly, we do our trick-or-treating in the daylight now on the last day of October, and will soon be waiting later and later each Sunday evening for astronomical darkness and the start of the Virtual Star Party

But there are some rumblings of change. This year, Idaho is pushing to scrap DST altogether. And, as is the norm in the often curious state of Florida, lawmakers have proposed to swing even further in the other direction, with a bill dubbed the “Sunshine Protection Act” looking to put the entire state on permanent DST year round in hopes of increasing tourism.

And just last year, a failed White House petition brought up the issue of ending DST. Perhaps their misspelling of DST as “Daylight Savings” (a frequent mistake) detracted from its credibility. What is it that makes us just want to throw that spurious “s” in there?

And that’s the wacky state of time we’re stuck with. Yes, we’ll be ferreting out those non-networked clocks around Astroguyz HQ Sunday morning, bleary from the loss of an hours’ sleep.

Our modest proposal is to do away with DST and time zones entirely, and adopt the use of Universal Time (also referred to as Zulu or Greenwich Mean Time) across the board. I know, it’s a tall order. In the meantime, we’ll be saying #DownWithDST on Twitter, as we await true astronomical darkness at an ever later hour.

And with that, we’ll open the debate up to you, the astute and intelligent readership of Universe Today. Is Daylight Saving Time worth it?

Watch the Close Pass of NEO Asteroid 2014 DX110 Wednesday Night

The orbital path and position of Apollo NEO asteroid 2014 DX110 just a week prior to disocvery. Credit- Created using NASA/JPL's Solar System Dynamics Small-Body Database Browser.

BREAKING- No sooner than the cyber-ink was dry on this post than we got notice of another 10-metre NEO asteroid 2014 EC passing Earth at just under 0.2 times the Earth-Moon distance – less than 64,000 kilometres – on Thursday, March 6th at 21:18 UT/4:18 PM EST. And the Virtual Telescope will be carrying this passage live as well on March 6th starting at 19:00 UT/2:00 PM EST. Bring in on, universe!

The Earth-Moon system gets a close shave on the night of Wednesday, March 5th 2014 when Near Earth Object (NEO) asteroid 2014 DX110 passes our fair planet at 216,000 miles or about 345,600 distant at around 21:06 Universal Time (UT)/ 4:06 PM EST.

About 30 metres in diameter, 2014 DX110 was discovered by the Pan-STARRS 1 survey on February 28th, and its orbit was initially refined using follow up observations made by the Great Shefford Observatory in West Berkshire, England.

And although the asteroid is no threat to Earth or the Moon – it makes a pass 232,800 miles from our natural satellite one hour and 22 minutes after its closest passage from the Earth – the asteroid is currently listed on NASA’s risk page for a 1 in 10,000,000 chance of impact with Earth on March 4th, 2046.

Of course, additional observations usually lower this remote possibility even further in the case of most newly discovered near Earth asteroids.  Visually, 2014 DX110 isn’t expected to brighten above +15th magnitude as it glides northward through the constellation of Camelopardalis at closest approach Wednesday night.

But the good news is, you can catch the passage of 2014 through the Earth-Moon system Wednesday night courtesy of our friends at the Virtual Telescope Project:

The webcast of the event is expected to go live at 20:30 UT, and will include live commentary.

Its been a busy last few weeks in terms of asteroid flybys, including a passage of Amor NEO asteroid 2014 DU110 earlier today at 15:54 UT/10:54 AM EST at 0.14 A.U.s or just over 20 million kilometres distant. And the folks at the Virtual Telescope Project will be covering another asteroid flyby on Sunday, March 9th starting at 23:00 UT/6:00 PM EST to track the 180 meter asteroid 2014 CU13. This large Apollo NEO is projected to pass 8 lunar distances or over 3 million kilometres away from the Earth on March 11th at 9:05 UT/4:05 AM EST.

It should be easy to pick out the motion of 2014 DX110 moving against the starry background at closest approach in real time. 2014 DX110 is an Apollo-class asteroid, and has an orbital period of 1192 days or about 3.26 years. It also has a fairly shallow inclined orbit relative to the ecliptic traced out by Earth’s path around the Sun, with a tilt of just over 5.7 degrees. This means that 2014 DX110 is approaching the Earth from just southward and behind it in its orbit around the Sun before crossing just inside of our orbit and northward of the ecliptic plane.

The discovery of asteroid 2014 DX110 was announced by the Minor Planet Center on Sunday, March 2nd in electronic circular 2014-E22. The orbit of 2014 DX110 takes it just interior of Earth’s at a perihelion of 0.83 A.U.s from the Sun and out to an aphelion of 3.6 A.U.s into the realm of the asteroid belt between Mars and Jupiter.

Generally speaking, asteroids passing interior to the Moon’s orbit grab our attention for further scrutiny. Looking back through the European Space Agency’s Near-Earth Objects Dynamics Site, asteroid 2014 DX110 also made an undocumented close passage of Earth on March 17th, 1998 at a minimum possible miss distance of 102,300 miles/163,680 kilometres distant, and a similar passage March 22nd, 1982. 2014 DX110 passed sufficiently close enough to Earth on these passages to alter its orbit so that it now returns to our terrestrial neighborhood every 13 odd years during the span of the 21st century. 2014 DX110 will be moving at a velocity of 14.8 kilometres per second relative to Earth on closest approach Wednesday night and will be inside the Earth’s Hill sphere of gravitational influence from March 4th to March 7th, though of course, it’s moving much too fast for capture.

2014 DX110 will be interior of the Moon’s orbit from 18:06 UT/1:06 PM EST on March 5th until 00:07 UT March 6th (7:07 PM EST on the night of March 5th). The large size – about the size of an office block – and the nature of its orbit, coupled with its relatively large velocity relative to the Earth rule out any potential for 2014 DX110 being space junk in solar orbit returning to Earth’s vicinity, though such objects from the Apollo missions and the Chinese Chang’e-2 Moon mission have been recovered as Earth asteroids before.

Such an impact risk, however remote, merits further study to refine the orbit of this potentially hazardous space rock. Surveys such as PanSTARRS, the Catalina Sky Survey and the B612 Foundation’s asteroid hunting Sentinel  space telescope slated for launch as early as 2017 are working to identify dangerous space rocks. The next and more difficult step will be mitigation and working to nudge these asteroids out of harm’s way, hopefully years in advance.

But you can breathe a sigh of relief Wednesday night as asteroid 2014 DX110 passes us at a safe distance. Thanks to Gianluca Masi at the Virtual Telescope Project for bringing this one to our attention!

Spectacular Views of Venus and the “Decrescent” Moon Worldwide

Credit:

Did you see it? Earlier this week, we wrote about the spectacular conjunction of the planet Venus and the waning crescent Moon this week, which culminated in a fine occultation of the planet by our large natural satellite on Wednesday morning. The footprint of the occultation crossed northern Africa in the predawn hours to greet daytime observers across southern Asia. And although the pass was a near miss for many, viewers worldwide were treated to a fine photogenic pairing of Venus and the Moon.

Credit: SculptorLil
An “aircraft/Moon/Venus tri-conjunction” captured February 26th from London, UK. Credit: Sculptor Lil

This was a highlight event of the 2014 dawn apparition of Venus, and some great pics have been pouring in to us here at Universe Today via Twitter, Google+ and our Flickr pool. We also learned a new word this week while immersed in astronomical research: a decrescent Moon.  We first thought this was a typo when we came across it, but discovered that it stands for a waning crescent Moon going from Last Quarter phase to New. Hey, it’s got a great ring to it, and its less characters than “waning crescent” and thus comes ready Tweet-able.

Credit: Gadi Eidelheit
Venus and the Moon in the predawn sky captured from Israel. Credit: Gadi Eidelheit @gadieid

Some great video sequences have emerged as well, including this fine grazing sequence of a daytime crescent Venus brushing past the crescent Moon taken by Shahrin Ahmad:

Shahrin journeyed to the northern tip of Peninsular Malaysia to the town of Perlis near near the Thai border to capture the graze. “It was a really close event,” he noted. “Today, the clouds began to appear and posed some real tense moments during the occultation.”

And although many weren’t fortunate enough to be in the path of the occultation, many observers worldwide captured some very photogenic scenes of the conjunction between the Moon and Venus as the pair rose this morning, including this great video sequence from  Ryan Durnall:

And clear skies greeted a series of early morning astronomers worldwide, who shared these amazing images with us:

Brad Timerson
This morning’s conjunction as imaged from Newark, New York. Credit- Brad Timerson @btimerson
Venus and the Moon the day prior to the occultation, shot by Ken Lord from Maple Ridge, British Columbia. Credit- Ken Lord.
Venus and the Moon the day prior to the occultation, shot by Ken Lord from Maple Ridge, British Columbia. Credit- Ken Lord.
The Moon approaching Venus on February 25th as seen from Carbon County, Pennsylvania. Credit: Tom Wildoner.
The Moon approaching Venus on February 25th as seen from Carbon County, Pennsylvania. Credit: Tom Wildoner.
Venus and the Moon rising through the fog: Credit: Joanie Boloney @jstabila
Venus and the Moon rising through the fog: Credit: Joanie Boloney @jstabila

John Chumack was also up early this morning and was able to capture this fine image of the pair rising above the University of Dayton’s PAC Center:

Credit: John Chumack, www.galacticimages.com
Venus and the Moon as seen from Dayton, Ohio. Credit: John Chumack, www.galacticimages.com

“All I had available was a point and shoot camera (not even mine!)” Chumack told Universe Today. “I’m surprised it came out okay, considering all the ambient light on Campus!!!” Chumack used a Fujifilm Finepix S1000 point and shoot camera, and went sans tripod, doing a 2″ exposure with the camera perched atop a trash can. The results of this ad hoc setup look great!

Astrophotographer Giuseppe Petricca based in Pisa, Italy north of the occultation path also grabbed this outstanding closeup image of the crescent pair:

Credit: Giuseppe Petricca
Taken using a Nikon Coolpix P90 Bridge camera on a tripod mount. Credit: Giuseppe Petricca

“This morning was awesome!” Petricca told Universe Today. “The weather forecast showed a compact high layer of clouds, but there were enough gaps between them that allowed me to see the conjunction in a lot of different moments.”

You can compare and contrast the twin crescents of Venus and the Moon evident in the above image. “You can easily see the phase of the Planet Venus and a lot of details on the lunar surface, despite the high clouds that partially blocked the view sometimes!” Petricca noted.

And finally, I give you our own humble entry, a  conjunction over suburbia snapped pre-caffeination:

DSC_0584   We think its great that you can sometimes catch a memorable glimpse of the celestial even from your own doorstep.

And when is the next occultation of a planet by the Moon? That would be next month, when Saturn is occulted by the waxing gibbous Moon for South Africa and Brazil after sunset on March 21st, 2014. We’re in the midst of a cycle of occultations of the ringed planet by the Moon, occurring every lunation through the final one this year on October 25th.

The next occultation of Venus occurs on October 23rd 2014, but is only one degree from the Sun and is unobservable. The next observable event occurs on July 19th 2015 for northern Australia in the daytime, and for a remote stretch of the South Pacific at dusk.

And its still not too late to spy Venus in the daytime today, using the nearby Moon as a guide. Here’s a handy simulation to aid you in your quest generated for mid-noon, February 26th:

stellarium
The orientation of the Moon and Venus at ~17:00UT, including a five degree Telrad bullseye. Created by the author using Stellarium.

And finally here’s handy chart of maps of occultations of Venus by the Moon for the current decade, just click to enlarge:

Occult 4.0
Occultations of Venus by the Moon from 2011-2020. Created using Occult 4.0.

Enjoy!