Wandering through the realms of the cosmos, pondering its huge vastness

Transits and Occultations

#ThrowbackThursday post: June 6, 2012 Transit of Venus

transit of venus copy copy

 

June 6th last year, stargazers from across the globe gathered together to watch one of the rarest astronomical spectacles.

Many turned their attention to the daytime sky to view the planet Venus passing directly between the Sun and Earth – a transit that won’t occur again for another 105 years.

The transit of Venus happens in pairs eight years apart – but then with more than a century between cycles. During the pass, Venus appeared as a small, dark round spot moving across the face of the sun.


Moon and Jupiter – January 22, 2013

Last January 22, 2013, the waxing gibbous moon appeared near the bright planet Jupiter in the evening sky.

As seen from the Philippines, the Moon and  Jupiter made a close approach within roughly 5 degrees of each other. Some folks in the Southern Hemisphere, however have seen Jupiter completely disappear behind the moon – an occultation.

During this event, the Moon was at mag -12.3, and Jupiter at mag -2.6, both in the constellation Taurus.

The sky condition was mostly cloudy. When the clouds parted, I was able to a couple of wide angle images which includes the two famous star clusters in Taurus — the Hyades and the Pleiades. In another image, the moon was shot at two different exposures to show the amount of separation between it and Jupiter.

Images were taken from Bulacan, Philippines around 8:40 – 9:00 pm PHT.

This slideshow requires JavaScript.


Lunar Occultation of Jupiter – August 12, 2012

During the early morning hours of August 12, Philippine sky observers had a great chance of witnessing a relatively rare occultation of Jupiter (and some of its largest satellites) by our Moon. In astronomy, an occultation is an event that occurs when an apparently larger body passes in front of an apparently smaller one. In this case, the moon passed in front of the planet Jupiter; the pair being visible in the morning sky in the Philippines about 5 hours and 53 minutes before the Sun. At the moment of closest approach, the Moon was at mag -11.3, and Jupiter at mag -2.2, both in the constellation Taurus.

Despite the presence of hazy skies and thin clouds, we were lucky to have been able to observed the occultation event. Once I located the moon with my naked eye, I immediately pointed my superzoom camera  to it and took an image. I found Jupiter close to the moon but it was covered with haze. A few minutes later, Jupiter slipped behind the bright lunar limb and was visible no longer. Half an hour later, I tried to capture a video of the reappearance of  Jupiter, but the clouds had thickened to the point where I could no longer find the moon. When the clouds  had finally gone out of sight, Jupiter was already emerging from behind the dark limb.

Still, considering the less-than-ideal conditions, it was quite a successful observation. 🙂

Sky condition: 70-80% cloudy
Camera used: Canon Powershot SX40 HS

I observed this event from Marikina City.

This slideshow requires JavaScript.


Skywatching Highlights: August 2012

This month, weather conditions permitting, skywatchers will be treated to the Perseid meteor shower, several planet conjunctions, a “blue moon” and a relatively rare lunar occultation of Jupiter (visible for some parts of the globe).

August 7-14: Spica, Saturn and Mars at Dusk 

The planets Saturn and Mars and the star Spica are close together in the first half of the month, low above the western horizon at dusk. They will form a triangle on the 7th an hour after sunset. Saturn will be the top of the triangle, while Mars will be on the lower right corner. Each side of the triangle is about 5 degrees. On the 14th, they will form an almost straight line: Saturn topmost with Mars lying between Saturn and Spica.

View of the western horizon at dusk on August 7 and 14, 2012 as seen from Manila Philippines. Images were screenshots from Stellarium.

August 12: Occultation of Jupiter by the Moon

For Philippine observers,  the waning crescent Moon will pass in front of Jupiter and its moons during a relatively rare event called occultation on the morning of August 12. In astronomy, an occultation occurs when one object is hidden by another larger object that passes between it and the observer. Prospects and timings for the event vary with location.

The event takes place while Jupiter and the Moon are low in the sky during the wee hours of the morning.

Local circumstances:

2012 Aug 12 02:43 Occultation disappearance of Jupiter (Mag -2.2)
2012 Aug 12 03:16 Occultation reappearance of Io (Mag 5.5)
2012 Aug 12 03:17 Occultation reappearance of Jupiter (Mag -2.2)
2012 Aug 12 03:18 Occultation reappearance of Europa (Mag 5.7)
2012 Aug 12 03:20 Occultation reappearance of Callisto (Mag 6.1)
2012 Aug 12 03:32 Occultation reappearance of Ganymede (Mag 5.0)

source: Pyxis Astronomy Educational Services

Jupiter and its largest satellites passing behind Earth’s moon.Image: Stellarium 

August 11, 12: Perseid Meteor Shower

The Perseids is one of the best annual meteor showers.

The best time to watch for Perseids is between midnight and dawn. This is when the shower’s radiant located between the constellations Cassiopeia and Perseus, lies highest in the northeast sky.

By the 12th, the moon will only be 25% illuminated and not nearly as intense as when near its full phase. This will allow fainter meteors to be seen as long as the moon lies outside your field of view.

Tip: Find a safe dark location with clear skies in the early morning hours in order to see the shower. This year, the shower peaks on a weekend so it’s more convenient to stay up late.

August 14: A line of planets along with a thin, waning, crescent Moon before dawn

Before dawn on the morning of the 14th August the planets Mercury, Venus and Jupiter and the Moon will line up in the eastern sky.  Look for A very thin crescent Moon to the upper right of Mercury an hour before sunrise in the northeast. Venus is to the upper right of the Moon, and a few degrees above them is Jupiter.

August 22: Waxing Crescent Moon joins Saturn, Mars and Spica

On the evening of the 22nd, a waxing crescent Moon, Mars, and Saturn will all lie within a circle just 6° in diameter.

August 31: Blue Moon (second full moon of August)

On the 31st, we will be able to witness a Blue Moon, the term given to the second full Moon in a calendar month.  But don’t expect it to be blue — the term has nothing to do with the color of the moon. [Origin of the term blue moon]

A composite image showing a lunar corona appearing around the full moon last last August 2, 2012

Clear skies!

 


Crescent Moon, Venus and Jupiter at Predawn on July 15th

Eastern sky at 4:00 am local time. Manila, Philippines. Image: Stellarium

Philippine sky observers will have a great chance to see all of the three  brightest objects of the night sky in close proximity to each other this weekend (weather permitting). On the morning of July 15th, the waning crescent moon will join the very bright “stars” Jupiter (upper) and Venus (lower) to form a nice celestial grouping, along with two prominent open star clusters — the Pleiades and the V-shaped Hyades —  in the constellation Taurus.

Venus has reached its greatest illuminated extent in Earth’s sky last July 12. Thus, it appears so dazzling now as a “morning star”  in our predawn sky, near Jupiter.

Meanwhile, in other parts of the globe, this celestial grouping event will be viewed as an occultation of Jupiter by the moon. An occultation is an event in which a celestial body covers another, farther away object, such as when the moon covers a star or a planet or when a planet or an asteroid covers a far away star. For this event, the moon will cover Jupiter for about an hour (the exact time and durtaion of the occultation is  dependent on the observer’s location). View the visibility map and timings of this event from IOTA.

Seeing Jupiter’s occultation is possible with the naked eye, but the look through a telescope, even using a small magnification, is marvelous. At first, two of Jupiter’s large moons (Io and Europa) will disappear behind the moon, then Jupiter will disappear and then the other two moons (Ganymede and Callisto).

Places close to the southeast will witness a ‘grazing occulation’ when Jupiter and its moons will skim the edge of the Moon. This will be well worth seeing through a telescope and Jupiter’s moons may be seen blinking in and out of view as they pass behind the lunar mountains. Further north and west a very close conjunction will be seen.

Don’t worry because even though we won’t be seeing this event in the Philippines this weekend, we are still lucky enough to see a very rare version of such an event next month, during the morning of August 12, 2012. That will be surely worth getting up to see!

jupiter-occultation-jul-201

Moon occulting Jupiter with its moons. Image: Stellarium

Observing occultations can also contribute to science. During the 80’s, Uranus occulated a distant star. Photos of the events showed that just before and after the occultation the star blinked several times. The theory then was developed that Uranus has a set of rings (like Saturn). When Voyager 2 reached Uranus it detected and photographed the predicted rings.

Don’t miss this event. Clear skies!

Related link: List of Notable Celestial Events in 2012


Venus Transit Observation in the Philippines

Viewing the Sun’s mole: People across the globe witnessed a very rare spectacular event that won’t be repeated until 2117.

I observed the whole duration of the  final  Transit of Venus of our lifetime at the College of Science Amphitheater in UP Diliman in a public viewing event  called ‘Rekindling Venus’ organized by members of various school-based astronomy organizations in the Philippines a last June 6, 2012.

There were lectures, talks, astro-images exhibit, free planetarium shows and telescope viewing, and more during the event, which have been attended by a lot of astronomy-enthusiasts coming from different places.

The sky was about 40-50% cloudy that day but it didn’t rain despite the weather forecast.

Observers set up their telescopes and pointed at the sun to view the transit.

Me and my own simple set up featuring my trusty Galileoscope equipped with a Baader 5.0 ND solar filter.

A lecture by Dr. Perry Esguerra of the National Institute of Physics explaining the phenomenon.

All smiles: Members of the UP Astrosoc, UPLB Astrosoc, and RTU Astrosoc posed for a group photo after the event . Image credit: Norman Marigza

Local newsgroups were present during the event and I was unfortunately spotted for a short interview. Haha!

This event was surely a memorable one.

Kudos to all the organizers and thank you to everyone who joined us in this event!


Art and Astronomy: Transit of Venus by Norman Marigza

Transit of Venus (medium: acrylic)

Only a few days left to the last transit of Venus of our lifetimes! Miss it and you won’t be able to witness it until the year 2117.

Amateur and professional astronomers from all over the globe were already gearing up for this big event. There were talks, lectures, public observations, videos, and other several projects and activities initiated by various local groups to promote this event among the public.

But one of  our astro-friends here has another cool way of sharing his knowledge and enthusiasm for this upcoming event, and that is through painting.

Shown above is an artistic depiction of the upcoming Transit of Venus created by Norman Marigza, a young Filipino artist who is also in the field of Physics and Astronomy. According to him, his two greatest passions in life are Art and Astronomy, hence he can do both. He’s surely a gifted person, isn’t he?

To see his other astro-artworks, please visit his website http://blogstargazers.blogspot.com/2010/01/astroart-by-norman.html

During the transit of Venus, we will be able to see the Venus as a small dot gliding slowly across the face of the sun. It happens when Venus passes directly between Earth and the Sun.

Historically, this rare alignment is how we measured the size of our solar system.


Rekindling Venus: Experience A Rare Celestial Event

Next month we will be the last people living today to witness one of the rarest astronomical events. On June 6, a special celestial event called the transit of Venus will take place, and it won’t be repeated in your lifetime.

During the transit, Venus will pass directly in front of the sun from Earth’s perspective, appearing as a small moving black dot.

The entire transit can be witnessed from eastern Asia, eastern Australia, New Zealand and the western Pacific, as well as Alaska, northern Canada and almost all of Greenland.

How rare is this astronomical event?

Transits of Venus occur in a pattern that repeats every 243 years with pairs of transits eight years apart separated by gaps of 121½ years and 105½ years. Only six of these transit have been recorded by civilization: 1639, 1761, 1769, 1874, 1882, and 2004. This June’s transit, the end of the 2004-2012 pair, won’t be repeated until the December 2117. This is the last chance for anyone alive today to see the rare celestial sight. Fortunately, the event is widely visible.

Unlike a total eclipse of the sun, which is visible only within a long narrow track traced by the moon’s shadow, during the 2012 transit of Venus the entire hemisphere of Earth facing the sun will get to see at least part of the planet’s solar crossing.

Importance

Astronomers during the 18th Century travelled thousands of miles and risked their lives to witness this precious sight.

They did so because they believed Venus held the key to the most pressing astronomical quest of the age: the size of the solar system.

In 1716, astronomer Edmund Halley realized that by timing the transits of 1761 and 1769 from widely-spaced locations on Earth it should be possible to triangulate the distance to Venus using the principles of parallax and give the distance between Earth and the Sun.

For astronomers today, the Transit of Venus offers a chance to gain insights into the planet’s notoriously thick, cloudy atmosphere, and use the refraction of sunlight to finetune techniques for hunting planets orbiting distant stars.

One of the most useful exercises will be to compare observations of the transit made by Earth-based telescopes, orbital telescopes and robot probes.

The Transit of Venus (TOV) is among the rarest astronomical phenomena and won’t happen again until the year 2117. So prepare now, and don’t miss out on this extremely special event!

Observing the TOV from the Philippines

Filipinos are lucky because the entire Philippines is well positioned to witness the transit of Venus on Wednesday 6th June 2012.

To those who are planning to observe this rare event, you might just be interested in joining us in this free public viewing.

Rekindling Venus
June 06 2012, 6am – 1pm
College of Science Amphitheater, University of the Philippines Diliman

This event was launched through the collaboration of the Australian Embassy, UP Astronomical Society, UP- Los Banos Astronomical Society, RTU Astronomical Society, DOST-PAGASA and D’Great Rovers.

This event is for FREE and is open to everyone. Even those who would be coming from other parts of the globe are invited.

For more details, please visit its Facebook event page:

https://www.facebook.com/events/159096590888136/

Contact Times

Local transit times for Quezon City, Philippines. source: http://transitofvenus.nl/wp/where-when/local-transit-times/

The general transit circumstances can be found here.

Safe Viewing

Warning: NEVER look at the sun with your naked eye, binoculars or a telescope. Serious and permanent eye damage, including blindness, can result.

The Black Drop Effect

The black drop effect occurs when Venus appears to “connect” to the edge of the Sun before actually reaching the edge. You can model the black drop effect by slowly pinching your index finger and thumb together. Your fingers seem to meet even before they touch. This optical phenomenon was originally thought to provide proof of Venus having an atmosphere. For an explanation of the black drop effect, check out the following links:

http://www.transitofvenus.org/history/black-drop
http://www.transitofvenus.nl/blackdrop.html

A YouTube video of modeling the black drop effect with your fingers:
http://www.youtube.com/watch?v=gm_kZd_wGkE

An online simulation of the black drop effect:
http://home.comcast.net/~erniew/astro/bd.html

Other resources if you are looking for more information on the Transit of Venus:


Transit of Venus Map in Many Languages

On 6 June, an event that takes place only four times every two centuries will enthral the world’s astronomers, as it has ever since the 1600s – but now it can provide priceless data in the hunt for habitable planets in deep space and in re-measuring the distance of the sun from Earth.

Venus will appear as a tiny speck on one side of the Sun in a few weeks and will slowly traverse the solar disc for a few hours. The movement of that little black dot may seem insignificant. But it is one of the rarest sights in astronomy, an event known as a transit of Venus. Miss this one and you will have to wait until 2117 for the next.

Image credit: NASA/LMSAL

As seen from Earth, only transits of Mercury and Venus are possible. On average, there are 13 transits of Mercury each century. In contrast, transits of Venus occur in pairs with more than a century separating each pair.

For Northern Hemisphere locations above latitude ~67° north (including the Philippines) all of the transit is visible regardless of the longitude.

A lot of astronomy-enthusiasts globally are preparing for this rare event. Some are even planning to travel in places where the transit will be fully visible.

As part of this preparation, visibility maps of the transit were created by volunteer groups to guide local observers. One of the efforts is called the Transit of Venus Project which is part of the Astronomers Without Borders (AWB) program. AWB is a global collaboration in astronomy.

Aside from providing useful information to the public about this event, the TOV Project also aims to form a collection of translated maps of the 2012 transit of Venus for different languages so that the transit of Venus will be enjoyed by more people around the world. Of course,  some people would appreciate a map in their own native language.

Michael Zeiler of  Eclipse-maps.com (and also one of the curators of the TOV Project website) sent me a message via Twitter asking for help with translating a summary map of the transit of Venus (June 5-6, 2012) into Filipino.

Here is a copy of the map:

These are the phrases to translate: World visibility of the transit of Venus on June 5 & 6, 2012 Venus overhead at transit maximum Entire transit visible Transit not visible Transit starts before sunset and ends after following sunrise Transit starts before sunrise and ends after sunset Transit visible from sunrise until end Transit visible from start until sunset Venus touches Sun’s disk at sunrise Venus within Sun’s disk at sunrise Venus within Sun’s disk at sunset Venus touches Sun’s disk at sunset

I made a draft of the translation in Filipino and consulted some professors from the Filipino Department of UP Diliman. Upon deciding that it the translated words were good enough, I emailed everything to Mr. Zeiler and he produced this map containing the translated phrases.

6 June 2012 Transit of Venus Visibility Map in our local language, Filipino. Credit: (map) Michael Zeiler/(translation) Raven Yu

Please take note that some of the phrases were not translated into its direct meaning but more of its contextual meaning so as not to confuse the map users.

Check out this link to view the translated maps of the 2012 transit of Venus for different languages.

If your language is not provided, you can help add a new map by following the simple instructions at this page.

You can also find local contact times of the transit at http://transitofvenus.nl/wp/where-when/local-transit-times/.

Remember that it is not safe to view the sun directly because it might damage your eyes. Read here for tips on how to safely view and photograph the transit using the right equipment and proper eye protection.

Don’t miss this rare spectacle! 🙂 Clear skies!


Notable Celestial Events in 2012

This year comes with its share of many remarkable skywatching events that we can participate in.  The most important is the rare transit of Venus across the face of the Sun in  June 2012. The next time this will occur again is in 2117. We have the unique opportunity to observe this. (A note to Philippine observers: We are in a good location for this event!)  Moreover, there’s also the Mercury elongation in February, Jupiter-Venus conjunction on March 13-15, the solar eclipses on May 21 and November 14 and  our favorite annual meteor showers.

The list below also contains some tips for Philippine observers.

Clear skies and happy observing! 🙂

February 20 – March 12 :  Best Chance to see Mercury

The planet Mercury will be far enough from the Sun’s glare to be visible shortly after sunset. Mercury will reach greatest elongation from the Sun on March 5, reaching a relatively bright magnitude of about -1. This will be your best chance to see the planet this year.

February 26 : Moon, Jupiter and Venus at Dusk

Look westward after sunset to see the moon and the dazzling planets Jupiter and Venus lighting up the western sky.

Moon, Venus and Jupiter | 6 pm | Manila

March 3 : Mars at Opposition

The red planet will be at its closest approach to Earth and its face will be fully illuminated by the Sun. This is the best time to view and photograph this planet. Mars will be an imposing naked-eye sight, shining at magnitude -1.2, just a bit dimmer than Sirius, the brightest star, and will be visible in the sky all night long.

March 14 : Conjunction of Venus and Jupiter

The two brightest planets in the sky will be within 3 degrees of each other in the evening sky. On March 25 and 25, the crescent Moon will be near the two planets, creating a dazzling evening spectacle.

March 26 : Crescent Moon, Jupiter and Venus line up at Dusk

Watch for the young waxing crescent moon and the planets Jupiter and Venus near each other in the west after sunset. The moon, Venus and Jupiter rank as the brightest, second- and third-brightest heavenly bodies of nighttime respectively. This will be last chance in 2012 that you will see them all-together at dusk.

moon, venus, jupiter - march 2012

March 27: Venus at Greatest Eastern Elongation

Venus reaches its greatest eastern elongation and will be separated from the Sun by 46°, its greatest apparent distance from the sun on our sky’s dome. Venus will set about three hours after sunset during this event. At this superb evening elongation for the Northern Hemisphere, Venus will stand above the setting sun. This is a good time to look out for the Schroter Effect, which predicts that dichotomy the 50% lit phase occurs a few days early for evening elongation.

April 3: Venus near the Pleiades

Venus will appear to the left of the Pleiades star cluster.  Especially with binoculars or a small telescope, this bright plant should appear swimming in a sea of stars.

April 15 : Saturn at Opposition

The ringed planet will be at its closest approach to Earth and its face will be fully illuminated by the Sun. This is the best time to view and photograph Saturn and its moons.

April 21, 22 : Lyrid Meteor Shower

The Lyrids are an average shower, usually producing about 20 meteors per hour at their peak. These meteors can produce bright dust trails that last for several seconds. The shower usually peaks on April 21 & 22, although some meteors can be visible from April 16 – 25. With no moon to get in the way this year, this really should be a good show. Look for meteors radiating from the constellation of Lyra after midnight.

*April 2012 is Global Astronomy Month!

May 21 : [Annular] Solar Eclipse

The path of annularity will begin in southern China and move east through Japan, the northern Pacific Ocean, and into the western United States. A partial eclipse will be visible throughout parts of eastern Asia and most of North America. (NASA Map and Eclipse Information) (Note: In the Philippines, we will be able to see a crescent sun at dawn.)

Partial Solar Eclipse | 6am | Manila

June 4 : Partial Lunar Eclipse

The eclipse will be visible throughout most of Asia, including the Philippines  Australia, the Pacific Ocean, and the Americas. (NASA Map and Eclipse Information) In the Philippines, we can observe this event as an eclipse at dusk, meaning we will be able to see an eclipsed moon rising.

eclipse magnitude:  37.6%
moonrise: 6:17 pm PHT
greatest eclipse: 7:03 pm PHT
partial eclipse ends: 8:07 pm PHT
penumbral eclipse ends: 9:19 pm PHT

(source: PAGASA)

June 4 Partial Lunar Eclipse | 7 pm | Manila

Go to http://shadowandsubstance.com/ to see an animation of the eclipse.

June 6 : Transit of Venus Across the Sun

This extremely rare event will be entirely visible throughout most of eastern Asia, eastern Australia, and Alaska. A partial transit can be seen in progress at sunrise throughout Europe, western Asia, and eastern Africa. A partial transit can be seen in progress at sunset throughout most of North America, Central America, and western South America. The next transit will not take place until the year 2117. (NASA Transit Information | NASA Transit Map)

Local circumstances for Philippine viewers

Venus transit of the Sun in June, 2004. Photo by Anthony Ayiomamitis.

July 15 : Moon, Venus and Jupiter near the Hyades and the Pleiades Star Cluster

See the three brightest objects in the night sky next to the Pleiades and the Hyades open star cluster in Taurus before dawn on July 15th.

Moon, Venus, the Hyades and Pleiades | 6 am | Manila

August 12, 2012: Occultation of Jupiter by the Moon

For Philippine observers, the morning of 12 August sees the waning crescent Moon pass in front of Jupiter and its moons in a so-called occultation. Occultations are comparatively rare events, which offer good photo opportunities for amateur astronomers. Prospects and timings for the event vary with location.

The event takes place while Jupiter and the Moon are low in the sky during the wee hours of the morning.

Local circumstances:

2012 Aug 12 02:43 Occultation disappearance of Jupiter (Mag -2.2)
2012 Aug 12 03:16 Occultation reappearance of Io (Mag 5.5)
2012 Aug 12 03:17 Occultation reappearance of Jupiter (Mag -2.2)
2012 Aug 12 03:18 Occultation reappearance of Europa (Mag 5.7)
2012 Aug 12 03:20 Occultation reappearance of Callisto (Mag 6.1)
2012 Aug 12 03:32 Occultation reappearance of Ganymede (Mag 5.0)
source: Pyxis Astronomy Educational Services

August 11, 12 : Perseids Meteor Shower

The Perseids is one of the best meteor showers to observe, producing up to 60 meteors per hour at their peak. The shower’s peak usually occurs on August 11 & 12, but you may be able to see some meteors any time from July 23 – August 24. The radiant point for this shower will be in the constellation Perseus. The near last quarter moon will be hanging around for the show, but shouldn’t be too much of a problem for a shower with up to 60 meteors per hour. Find a location far from city lights and look to the northeast after midnight.

October 5 : Moon-Jupiter Conjunction

The King of the Planets and the crescent moon will reunite for a close celestial pairing. Check the eastern sky around midnight to spot these two objects that are less than one degree apart!

Moon and Jupiter at 11 pm | Manila

October 21, 22: Orionid Meteor Shower

The Orionid Meteor Shower usually reaches its peak around October 21, having an average of 20 meteors per hour. The Orionids are fast meteors and also have fireballs. These meteors radiate near the boundaries between the Great Hunter Orion and Gemini. The cometary debris left behind by Comet Halley — bits of ice, dust and rubble — create the Orionid meteor shower. It last visited Earth in 1986.

A good show could be experienced on any morning from October 20 – 24, but some meteors may be seen any time from October 17 – 25. The first quarter moon will set by midnight, leaving a dark sky for what should be a good show.

The best time to view these meteors is usually in the wee hours before dawn. That time holds true no matter what time zone you’re in.

The red lines illustrate the position of the radiant for the Orionid Meteor Shower. The radiant is the point in the sky from which the meteors appear to originate from.

November 13 : Total Solar Eclipse

The path of totality will only be visible in parts of extreme northern Australia and the southern Pacific Ocean. A partial eclipse will be visible in most parts of eastern Australia and New Zealand. (NASA Map and Eclipse Information (Note: This event is not visible in the Philippines.)

November 17, 18 : Leonids Meteor Shower

The Leonids is one of the better meteor showers to observe, producing an average of 40 meteors per hour at their peak. The shower itself has a cyclic peak year every 33 years where hundreds of meteors can be seen each hour. The last of these occurred in 2001. The shower usually peaks on November 17 & 18, but you may see some meteors from November 13 – 20. The crescent moon will set early in the evening leaving dark skies for what should be an excellent show. Look for the shower radiating from the constellation Leo after midnight, and be sure to find a dark location for viewing.

November 27 : Conjunction of Venus and Saturn

These two bright planets will be within 1 degree of each other in the morning sky. Look to the east around sunrise.

December 3 : Jupiter at Opposition

The giant planet will be at its closest approach to Earth and its face will be fully illuminated by the Sun. This is the best time to view and photograph Jupiter and its moons.

December 11 : Saturn, Venus, Mercury and the Crescent Moon at Predawn

Check the eastern sky about an hour before dawn to see this magnificent celestial display of the three planets and the thin lunar crescent.

Eastern sky at around 5 am | Manila

December 13, 14 : Geminid Meteor Shower

Considered by many to be the best meteor shower in the heavens, the Geminids are known for producing up to 60 multicolored meteors per hour at their peak. The peak of the shower usually occurs around December 13 & 14, although some meteors should be visible from December 6 – 19. The radiant point for this shower will be in the constellation Gemini. This year the new moon will guarantee a dark sky for what should be an awesome show. Best viewing is usually to the east after midnight from a dark location.

# # #

References:

  • Stellarium Planetarium Software

When Luna Occults Subra

Last March 17, 2011 , the University of the Philippines Astronomical Society (UP AstroSoc) set up at the PAGASA Astronomical Observatory in UP Diliman to observe the  occultation of the 3.3 magnitude star, Omicron Leonis (or Subra) by the 92% illuminated waxing gibbous Moon.

This event was headed by UP AstroSoc associate member and alumni, Anthony Urbano of EtenyWorks. Kuya Eteny, as the members fondly call him, was experienced in observing occultations.

During this observation, he brought his 6″ Newtonian Equatorial Reflecting Telescope (NERT) with a self-designed home-built clock drive attached to the telescope’s equatorial mount. To record the occultation event, a Canon S3IS connected to a laptop was mounted to the telescope’s eyepiece by means of a fabricated camera adapter. This modified camera can show it’s system time on its on-screen display. According to Kuya Eteny, the default precision of the on-screen timer is limited to 1 second, but a patch, currently made available only for Canon S3IS, increased the clock’s precision to 1/100 of a second — the maximum precision of the camera’s built-in clock.

The telescopes set up which included the 6" NERT (left-most)

You can learn more about this improvised clock drive project, the camera modification and  the rest of observation set up by visiting his site where he posts a lot of cool stuff about observation and instrumentation. His inventions are most fit for those amateur astronomers interested in modifying their own telescopes and cameras especially for the purpose of doing astrophotography. 🙂

The event was from 10:20 UT (ingress) and ended at 11:10 UT (egress). Although it can be classified as a ‘bright star occultation’,  the light coming from the target star wasn’t bright enough to pass through the thick clouds during the entire event. By around 11:50 UT, we decided to packed up since there was still no trace of the star near the Moon.

On-screen display of Canon S3IS (with the CHDK firmware upgrade) showing the Moon under the dark patches of clouds. The system time (upper right corner) in this screenshot reads 19:18:44 PST (11:18:44 UT) The occultation event during this time was over, yet there was still no sign of Subra which should be located a few degrees above the Moons upper right limb.

When the Moon passes in front of a background star during occultations, the shadow of the Moon cast by the star sweeps across the Earth. When the leading or trailing edge of the Moon’s shadow crosses an observer, the observer sees the star “disappear” or “reappear”. These events are usually very sudden, and timing the instant of occultation is an important astronomical measurement.

But why is it important to observe lunar occultations?

  • Observing lunar occultations is important because the results improve our knowledge of the position and motion of the Moon. For example, when you time the disappearance of a star behind the edge of the Moon to 0.1 second accuracy (a value easily attainable), you are actually fixing the position of the Moon’s edge in space to an accuracy of about 80 metres. i.e. you are making a measurement with a precision of only 80 metres over a distance of 384,400 km. (This is one of the most accurate measurements an amateur observer can make in any branch of science!)
  • Combining many such measurements of the Moon’s position over a long time gives astronomers new information about the Moon’s motion and orbit. For example, total occultation observations have shown that the Moon is spiralling away from the Earth at a rate of a few centimetres per year.
  • Total lunar occultations have also been used to provide valuable information about star positions, about the hills and valleys on the edge of the Moon, and to discover new double stars.

Aside from occultations by the Moon, there were also Planetary Occultations and Asteroid Occultations. Just as the Moon passes in front of background stars, so too do planets and minor planets (also called asteroids).

Planetary occultations are occultations of stars by the passing of a planet in front of it. However planetary occultations occur less frequently than lunar occultations because the planets appear so much smaller in our sky than does the Moon. Nevertheless, observing occultations of stars by planets has yielded some stunning discoveries – for example, the rings of Uranus, and the atmosphere around Pluto.

On the other hand, Asteroid Occultations are occultations of stars by the passing of an asteroid in front of it. Asteroid occultations can occur anywhere on the surface of the earth. A few naked eye stars have been occulted during the past 20 years, but most occultations are of quite dim stars typically between magnitudes +9 and +12. An occultation might occur at any time of night, on any day of the week. More and more fainter asteroid occultations are being predicted, so that it is likely that at least 5 events will likely cross your area in the coming year.

While occultations of bright stars by major planets are very rare, occultations by asteroids are a little less so. This is not because any one asteroid has a greater chance of passing in front of a star. Rather, it is because there are so many more asteroids to choose from!

Anyway, asteroid occultations are the only way — apart from spacecraft missions to asteroids and radar observations of nearby objects — to determine the approximate size and shape of those bodies and are, of course, much cheaper.

If, as an amateur astronomer or telescope owner, you would like to be part of history, contribute something relevant to the study of astronomy, or would love to see sights that few have witnessed, then occultations are the thing for you. The occultation process offers discovery and research. It is possible for amateur astronomers to discover new companions of stars, help to improve the polar diameter of the sun and moon, identify the existence of possible satellites orbiting asteroids, to improve knowledge of heights of lunar mountain peaks and depths of valleys in the polar regions, determine corrections to ephemeris errors and assess star position errors, improve knowledge of the shape and sizes of asteroids, and more through occultation science. It does not matter where you live in the world. If you have access to a computer and possess a telescope of at least 4-6 inches, know your geodetic position either from GPS or a good topographic map, have a source of time signals and tape recorder, you can make your own observations of these rare and critical events.

The International Occultation Timing Association (IOTA) web site can be found here and that of the International Occultation Timing Association/European Section (IOTA/ES) web site can be found here.

 The IOTA web site contains predictions that are updated frequently.

To be able to observe and correctly record an occultation event, you should first have knowledge to find your way about the sky. Most stars that are occulted by asteroids have average apparent visual magnitude of 10.

The program Win-OCCULT, authored by David Herald in Australia, provides accurate predictions of all types of occultations and related phenomena. You can obtain a copy of Win-OCCULT by downloading it from here.

Good luck! 🙂


Lunar Occultation of Omicron Leonis — 17 March 2011

For Philippine observers, a star-moon eclipse will occur on March 17, 2011, from 6:20 pm to 7:10 pm (PHT). The event will be visible to the naked eye, but is best observed with a pair of binoculars, or with an astronomical telescope.

image reposted from eteny.wordpress.com

DETAILS (from AstronomyLive.com)

VISIBILITY: This will be the second time this year that OMICRON LEONIS or Subra will be occulted. This time it’s again visible in south-east Asia and the Phillipines but now also Australia and New Zealand can join the party! The star will disappear on the dark side, meaning easy to spot and very interesting to broadcast.

STAR & MOON: Omicron Leonis is a +3.5 magnitude star. The waxing Moon will be 92%, so there is some lunar disturbance. It all starts in Iba, the Phillipines at 10:50 Universal Time. Check the link below, to see when it starts and ends at your location.

LIVE BROADCASTING SCORE: Good. Although the Moon phase is not optimal, this occultation is beautiful to watch mainly because it disappears behind the dark side of the Moon. Another thing that makes broadcasting this occultation interesting is that the white line on the map – locations where the star will disappear and reappear behind the mountains on the lunar edge during darkness- is near the densely populated cities of south-east Australia. So when living near those white lines you should really find yourself a telescope and watch this occultation taking place.

HOW TO READ THE MAP BELOW?: The white line indicates that the occultation takes place during darkness. Blue is occultation at twilight and the dotted red line indicates occultation during daylight. Cyan means the occultation takes place when the Moon rises or sets. Another important feature of these maps is that you can check grazing locations (on the lines), places where the star will ‘scrape’ the Moon and thereby is occulted for a very short period of time.

LINKS:



Lunar Transit Captured by SDO – March 4, 2011

 

There is the Moon eating away at the Sun! 🙂 Image credit: NASA/GSFC/SDO

 

NASA’s Solar Dynamics Observatory (SDO) satellite captured the dark moon creating a partial eclipse of the Sun last March 2-4, 2011.

More still images here.

Watch HD Video.

These images, while unusual and cool to see, also have practical value to the SDO science team. Karel Schrijver of Lockheed-Martin’s Solar and Astrophysics Lab explains: “The very sharp edge of the lunar limb allows us to measure the in-orbit characteristics of the telescope e.g., light diffraction on optics and filter support grids. Once these are characterized, we can use that information to correct our data for instrumental effects and sharpen up the images to even more detail.”

On October 7, 2010, SDO observed its first lunar transit when the new Moon passed directly between the spacecraft (in its geosynchronous orbit) and the Sun.


ISS Solar Transit Observation – Manila, Philippines (Jan. 13, 2011)

Last 13 January 2011, an International Space Station (ISS)  Solar Transit event visible in some parts of Metro Manila occurred at around 8:30 am PHT (Philippine Time). The relative rarity of  ISS Solar and Lunar Transits here in the Philippines plus the fact that I were fortunate enough to be very near the path of visibility of this transit inspired me a lot not to miss this event.

ISS Solar Transit Visibility Path | obtained from http://www.calsky.com courtesy of Anthony Urbano

Along with my UP AstroSoc orgmates and some fellow amateur astronomers from RTU AstroSoc and from the  Philippine Astronomical Society (PAS), we set up our equipment to observe this passage of the ISS in front of the Sun’s disk at the Manila Observatory in Quezon City, Philippines.

Beemi, our "command center", under an umbrella

Setting up our equipment and preparing the Baader solar filters

Our two NERTs -- 6" Newton (black) and 4.5" Datascope (white)

I already have some experience in observing solar eclipses but this was my first time to try timing and capturing a solar transit. Unlike eclipses, ISS transits are more challenging to observe because they happen too fast. To give you an idea of how fast these events occur, here is a video clip which I got from Youtube showing the ISS transiting in front of the Sun’s disk. It was captured by students of the Westfalenkolleg Dortmund on August 7, 2010 at 17:31 pm.

The transit above lasted for 1.06 seconds. The one we were to observe will have a duration of about 0.91 seconds — too swift to be captured using cameras so we opted to record a video of it instead.

Following are the transit details including the timings. The data was obtained by our UP AstroSoc orgmate and team leader, Anthony Urbano from www.calsky.com.  All times are in PST (Philippine Standard Time) or UT+8.

Distance from center-line: 1.06km
Path Width: 13.6km maximum
Time of Ingress: 8h30m40.6s
Culmination: 8h30m41.20s
Time of Egress: 8h30m41.6s
Transit Duration: 0.91s
Separation Angle: 0.037°
Position Angle: 121.2°
Satellite at Azimuth: 123.6° ESE at culmination
Satellite at Altitude: 26.4° at culmination
Angular Diameter: 25.6″
Angular Velocity: 35.2’/s
Ground Velocity: 7,457m/s
Size: 73.0m X 44.5m X 27.5mSatellite Distance: 723.6km

In clock-face concept, the space station will appear to move toward: 8:58

And by the way,  Anthony Urbano or Kuya Eteny, as we fondly call him, is a gadget master. 😀 He has invented a lot of devices like a universal camera adapter that allows any point-and-shoot camera (and even SLRs) to be attached to any optical system (binoculars, telescope, microscope, etc.). He even brought one of his camera adapters during this observation to attach the video camera to his 6″ Newtonian Reflector Telescope. Moreover, he has also modified some gadgets  like DSLRs to be more useful in astronomical observations and astrophotography. This guy is truly remarkable for possessing such great talent! 🙂

video camera and the L-type universal adapter

Our amazing gadget master 🙂

An hour before the ingress, the sky around our location was partly covered in clouds. The sky condition got even worse as the predicted time approached. We waited for several more minutes, just in case the clouds clear up and the actual time of transit is later than predicted. In the end, we didn’t see any trace of the ISS due to thick cloud cover. We packed up and left at around 9:30 am.

Though we were not able to accomplish our goal of recording this transit event, the experience is always worth it.  😀 Thanks to Kuya Eteny for informing us about this event and inviting us to observe with him.

I’m looking forward to more transit and solar observations. 🙂

 

*Photos by Bea Banzuela

======================

Update: Another group of fellow Filipino amateur astronomers from the Astronomical League of the Philippines (ALP) were lucky enough to observe and take images of the ISS transiting the Sun. Their observation report and images can be found here.