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

Astro Trivia

Photographing the Lunar ‘X’

Today I had a nice opportunity  to spot the “Lunar X” on the First Quarter Moon! The Lunar “X” is a well-known “optical feature” on the Moon, which resembles the letter “X” when the lunar terminator is along just the right lunar longitude. The intersecting crater walls of Purbach, La Caille and Blanchinus make the illusion “X” that is only visible for a short time.

Based on my observations during the past few months, it is possible to see the Lunar X when the moon is nearly 54% illuminated.This is why you cannot see it every month. In fact, the last time I was able to image it was during October 2012.

By the way,  I refer to Stellarium, a free planetarium software, to determine the lunar phase and illumination  during a particular date and time for my location. Note that the values given by Stellarium may not be very exact, but they are still very useful as guides for amateur astronomers.

lunar x - january 19 copy

My first image of the Lunar X:

Lunar X copy

Both images were taken using my Canon Powershot SX40 HS camera.

Advertisements

Paschal Full Moon and the Astronomy of Easter

The image shown above was last night’s Full Moon called the Paschal Full Moon.

In Christianity, the first astronomical full moon after the vernal (spring) equinox is usually designated as the Paschal Full Moon or the Paschal Term. Traditionally, Easter is observed on the Sunday after the Paschal Full Moon.

Image taken via afocal method (Panasonic Lumix DMC-FH2 on my Galileoscope)

Related links:


The Solitary Star

Fomalhaut, the Solitary star

Have you ever noticed the loneliest star?

Fomalhaut (or Alpha Piscis Austrini) is the brightest star in the faint constellation Piscis Austrinus – the Southern Fish – and the 17th or 18th brightest in the sky. It can be seen low in the southern sky during these evenings.

Fomalhaut, sometimes called the Autumn Star, appears in a part of the sky that is largely empty of bright stars. For this reason, it is also often called the Lonely One or Solitary One.

But, it’s been less lonely since the discovery of its planet ‘Fomalhaut b’ in 2008. Fomalhaut b – the first extrasolar planet to be imaged at visible wavelengths – orbits the loneliest star.

Fomalhaut is also one of the first known to have a disk of dust around it, a sign that more planets might be forming there.

Image taken last October 31, 2011 at 8:31 pm.


Halloween Celebration and Astronomy

IC 2118 (Witch Head Nebula) in Orion. Original image credit: NASA/STScI Digitized Sky Survey

Did you know that Halloween is a significant day on the astronomical calendar?

Surprising, isn’t it? Halloween means more than just a day for spooky stuff, costumes and candy treats. This celebration is actually a cross-quarter day which means it falls approximately half way between the Autumnal Equinox, the astronomical start of fall and Winter Solstice, the astronomical start of winter.

Red crosses mark the year’s cross-quarter dates. Credit: NASA

It’s no coincidence that Halloween has a dark side. Halloween is believed to have originated with the ancient Celtic harvest festival Samhain. Samhain roughly translates to “summer’s end”. It was the date that signaled the start of winter when most plant life is dead. A season where food would be limited and living conditions would be less than favorable. It was a day of celebration and of dread, the line between the living summer and the dead winter.  It was not until middle ages that the day was associated with the Christian holidays of All Saints Day and All Souls Days.

This year’s Halloween has  a bit of something for everyone. This is because the eastern sky during late October nights is filled with deep sky treats for stargazers of all types.

For the naked eye observer, the first of the brilliant stars of winter start to peek over the eastern horizon: Capella and Aldebaran. Three of the nearest galactic star clusters are visible to the naked eye: the Pleiades, the Hyades, and the Perseus Moving Cluster.

Halloween Sky Treat — eastern sky on Oct. 31, 2011 (around 9:30 PM)

Want more? Check out these links to see a gallery of eerie and spooky space images:

Happy Halloween! 🙂


The ‘Mini’ Full Moon of 2011

October’s Full Hunter’s Moon nearly coincides with the apogee of the moon’s orbit, or the point at which the moon is farthest from Earth. That makes October’s full moon appear smaller than usual, the opposite of the “supermoon” effect that occurred earlier last March when the moon was full during its closest approach to Earth.

October’s (almost full) Hunter’s Moon surrounded by thick gray clouds. This was the smallest, farthest full moon in 2011.

The moon reached its peak fullness at 2:06 a.m. UT last Oct. 12. Shortly thereafter, the moon was at its farthest point from Earth, which it reaches once a month. The moon’s orbit is elliptical rather than perfectly circular, which is why the distance from Earth to the moon varies by tens of thousands of miles depending on the time of month and year. The moon’s orbit is also always slightly changing because of differing effects of the sun’s gravity.

Though we couldn’t notice with our own eyes, the Moon’s apparent size changes throughout the year and this is because of the phenomenon called Lunar libration, or the wobbling of the Moon.

Below is an animation which demonstrates this effect. It shows the geocentric phase, libration, position angle of the axis, and apparent diameter of the Moon throughout the year 2011, at hourly intervals.

Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio

Clear skies!


Bye bye, Mr. Teapot

Sagittarius (plus a faint apparition of the Milky Way?) over our local suburb. Click on image to enlarge.

 As summer time has already ended, the constellation Sagittarius, along with the other Summer constellations sets earlier during the month of October.

Sagittarius is believed to have originated with the Babylonians. He was their god of War, and he stands with his bow aimed at the heart of Scorpius, the scorpion. Like Centaurus, he is a half man, half beast creature.

We in modern times may not be able to imagine the stars of Sagittarius as a Centaur. Instead, many stargazers know the stars of Sagittarius as a “Teapot”. This asterism is really easy to recognize.

Sagittarius is an important constellation in that it marks the direction of the center of our galaxy, the Milky Way. It also contains more Messier objects than any other constellation in the sky.

Earlier this evening, I took the chance to take an image of the “Teapot” before it disappears in the night sky. I was also planning to image Scorpius but it was already too low in the south west. As I looked at the image more closely, I began to noticed something interesting. On the right (just above its lid), there is a faint cloud-like patch that resembles the Milky Way. I got surprised. 🙂

Could it be really possible to see a faint apparition of the Milky Way in this light-polluted suburb?

Perhaps, yes.


Happy Birthday Neptune!

On Tuesday, July 12, 2011, the planet Neptune will complete its first revolution around the sun since its discovery on September 23, 1846. As it takes Neptune 164.79 Earth-years to go full circle through the constellations of the Zodiac, it is only now completing its first full orbit since its detection by humans. Hence the anniversary celebration.

Neptune, the 8th planet outward from the sun, is presently the most distant planet in the solar system. That’s because the International Astronomical Union reclassified Pluto as a “dwarf planet” in 2006. By the way, Neptune circles the sun three times for every two times that Pluto does.

There is much to commemorate — Neptune’s discovery marked a turning point in astronomy. Its existence was revealed, not through a serendipitous observation by an astronomer but by the careful work of mathematicians. They calculated that perturbations in the orbit of Uranus, then thought to be the sun’s most distant planet, could only be explained by the existence of another, even remoter world whose gravity was affecting Uranus’s path.

The mathematicians – Englishman John Adams and Frenchman Urbain Le Verrier – made their calculations separately. Both agreed, however, where in the sky astronomers would pinpoint the planet causing those perturbations. But they dealt with the information very differently, says historian Allan Chapman of Wadham College, Oxford.

As Neptune is too faint to be seen by the naked eye,  a pair of binoculars or a telescope is needed to view this world if you know where to look.   This  detailed sky chart will help you to find Neptune’s place in the sky — it will be located in Aquarius, the constellation where astronomers discovered the blue planet.

Next month Neptune reaches opposition and is a decent target for observers.

Happy Birthday, Neptune!  🙂


Happy Summer Solstice!

Diagram showing the different positions of the Earth throughout its elliptical orbit around the Sun

According to PAGASA, Philippine nights are at their shortest and daytimes are at their longest around the Summer solstice, which falls on June 22 at 1:16 A.M. (Philippine Standard Time). This is the time when the Sun attains its greatest declination of +23.5 degrees and passes directly overhead at noon for all observers at latitude 23.5 degrees North, which is known as the Tropic of Cancer.

The Sun rises farthest from the east, sets farthest from the west and reaches its northern limit during the summer solstice. Image credit: Andrew Fazekas

Sol + stice derives from a combination of Latin words meaning “sun” + “to stand still.” As the days lengthen, the sun rises higher and higher until it seems to stand still in the sky.

Celebrating the Summer Solstice

Amazed by the great power of the sun, civilizations have for centuries celebrated the first day of summer otherwise known as the Summer Solstice, Midsummer (see Shakespeare), St. John’s Day, or the Wiccan Litha.

Perhaps the most enduring modern ties with Summer Solstice were the Druids’ celebration of the day as the “wedding of Heaven and Earth”, resulting in the present day belief of a “lucky” wedding in June.

Today, the day is still celebrated around the world – most notably in England at Stonehenge and Avebury, where thousands gather to welcome the sunrise on the Summer Solstice.

Sunrise over Stonehenge on the summer solstice, 21 June 2005 (image: Wikipedia)

Whatever religious, mystical or spiritual elements were central to Stonehenge, some archaeologists say that its design includes a celestial observatory function, which might have allowed prediction of eclipse, solstice, equinox and other celestial events important to a contemporary religion.

As a matter of fact, when one stands within Stonehenge (facing north-east through the entrance towards the Heel stone or Sun stone one sees the sun rise above the stone at summer solstice.


Red Moon in June: Public Stargazing and Total Lunar Eclipse Observation

The University of the Philippines Astronomical Society (UP AstroSoc) invites everyone in observing the spectacular total lunar eclipse on June 15 – 16!

After the moon got super huge last March 2011, this coming June 16 2011, the moon will once again be spectacular to watch as it turns red because of the total lunar eclipse.


The first of the two eclipses of 2011 will occur on the said date and it will start at around 1:25AM and will end at around 7AM but the fun part where it turns red will be on its totality at around 4AM.

What is more special about this eclipse is that this will be the darkest lunar eclipse in almost 100 years as the centers of the sun, the earth and the moon would nearly be on one straight line. This also means that the Moon will pass deeply through the Earth’s Umbral Shadow which will make the totality phase last about 100 minutes.

This event is open to all. Come and invite your family and friends, and witness this wonderful sky show.

Clear skies, everyone!


Spring’s First Full Moon Along Galaxy Street!

April’s Moon reached its full phase last April18 at 10:45 AM PST (2:45 AM UT).

During Palm Sunday in the Philippines last April 17, 2011, I and some friends spotted the 99.5% full Moon rising at dusk. It looked like a big ball of cheese hanging up in the sky along a street named Galaxy Street in Panorama, Marikina City.

It seemed larger near the horizon during moonrise than it does while higher up in the sky.

According to EarthSky.org, this is the first full moon of springtime for the northern hemisphere. We in this hemisphere call it the Pink Moon, to celebrate the return of certain wild flowers. Other names are Egg Moon, Sprouting Grass Moon, or Easter Moon.

The first Full Moon of spring is also usually designated as the Paschal Full Moon or the Paschal Term. In most years, the Christian celebration of Easter is observed on the Sunday after the Paschal Full Moon. If the Paschal Moon occurs on a Sunday, Easter is the following Sunday.

Interesting Fact:

For those living in the Southern Hemisphere, the autumn counterpart of the Paschal Full Moon is called Harvest Moon, the closest full moon to the autumnal equinox. 

What sets the Harvest Moon apart from the others is that instead of rising at its normal average of 50 minutes later each day, it seems to rise at nearly the same time for several nights.

However, in direct contrast to the Harvest Full Moon, the Paschal Full Moon appears to rise considerably later each night.

Here are the other photos taken by me and two of my fellow UP AstroSoc folks, Andre Obidos and Bea Banzuela.

A combination of the overexposed (1/8 sec exp., ISO-1600) and underexposed (1/320 sec. exp., ISO-400) photo of the Moon.

Cameras used:
*First 2 photos — Panasonic Lumix DMC-FS7 10.1 MP Digital Camera
*Wide angle photos — Canon PowerShot SX20 IS

All images can be clicked to see high-res versions.