the the APPULSEOfficial Newsletter of the Philippine Astronomical Society

Bringing the heavens down to earthDecember 2007

Volume 39 No. 45 �

Volume 39 No. 45

Fluorine: The Mysterious Interstellar Element

Every chemical element on earth has a story written among the stars.

The nitrogen in the atmosphere and in every living organism’s body blossomed in the stars that are somewhat heavier than the Sun, like Capella, which cast their outer layers as planetary nebulae when they died.

The oxygen that we breathe and the neon lights glowing on giant bill boards along the highways were cooked in massive stars like the Antares that later spewed elements into the galaxy by exploding as supernovae. And supernova explosions forged much of the ion in human blood and the gold that makes up every type of

accessory man could think of.

As solar mass stars die, they shed their outer layers in

breathtaking planetary nebulae such as the Helix Nebula in Aquarius. By analyzing shed stellar skins, astronomers

learn about the chemical history of the dying star. Such studies helped to determine the possible origin for one of the most elusive elements, fluorine.

Fluorine is found in toothpaste, fluoridated water and in fluorite – a beautiful mineral. But its origin is a mystery that baffles astronomers

and physicists alike. According to one theory, fluorine owes its existence to neutrinos, the ghostly particles that shoot through every one every second from the Sun’s core. Another idea holds that it originates from the red giants due to the fusion of nitrogen while a third maintains that massive blue stars known as Wolf Rayet stars - have blown off their outer layers and

did the trick.

How does it happen?

Red giant and Wolf Rayet stars manufacture fluorine by wielding

the elements’ nemesis, the proton. The nuclear reaction sequence is complex and does not happen easily. It starts when the heavy carbon isotope, carbon -13, fuses with helium-4 and loses a neutron.

Image courtesy of John Nassr

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APPULSETHE

editorial Advisory BoardEdna Azucena

Victoria Evarretta

editorial StaffAgnes OclaritEditor-in-Chief

Marnelli Atienza Francis Ferdinand Irlandez

Layout Editors

John NassrMarnelli Atienza

Francis Ferdinand IrlandezLeogiver ManoscaVictoria Evarretta

Edna AzucenaMounien Beldia, Ph.D.

Contributors

The Appulse is published monthly by the Philippine Astronomical Society.The appulse © 2007. All rights reserved. Letters, Articles submissions, observations, of report can be sent to: Email: appulse@philastrosoc.org

Website: www. philastrosoc.org

2 Appulse - December 2007

13C + 4He -----→ 16O + neutron

The neutron then impacts nitrogen or aluminum to liberate the proton.

14N + neutron -----→ 14C + proton

26Al + neutron --→ 26Mg + proton

These protons end up producing fluorine through a sequence that starts when nitrogen-14, a left over from hydrogen burning via CNO cycle, meets helium to create a radioactive fluorine-18.

This fluorine-18 is unstable and

soon decays into heavy oxygen isotope, oxygen-18 by releasing a positron (a positively charged electron).

18F -----→ 18O + positron

Now the proton enters the reaction, transforming oxygen-18 into nitrogen-15.

18O + proton ---→ 15N + 4He

The nitrogen-15 then encounters helium and finally forges fluorine.

15N + 4He ---→ 19F

After the Helium shell flash in a red giant star, the fluorine reaches the star’s surface, where cooler temperature prevents the protons or helium-4 from destroying it. A similar sequence in Wolf-Rayet stars can also produce fluorine at the start of helium burning. The star’s wind then blows the element into space before the temperature rises enough for the helium- 4 to destroy it.

Carbon stars such as T Lyrae are among the rare places in the galaxy where fluorine is relatively abundant. These stars can have more than 60x the amount of fluorine in the Sun.

Astronomers believe that moderately high mass giants produce less fluorine than giants of lower masses. Evidence comes from objects such as the dying stars that created the Egg Nebula in Cygnus; it originally contained about 7 solar masses. Assays of the Egg’s ejected ripples have found little evidence of the element.

Interstellar Fluorine

In 1980, the Copernicus satellite discovered fluorine in the spectrum of Delta Scorpii. Interstellar fluorine gas between and in the Beta° subgiant absorbs particular wavelengths of the star’s far ultraviolet rays.

Source: Explorations: An Introduction to Astronomy by:Thomas T. Arny

In 1997, the Infrared Space Observatory observed a molecular cloud named Sagittarius B2 near the galactic center and discovered the first, and so far, the only known fluorine bearing interstellar molecule, hydrogen fluoride (HF). HF is the dominant form of the gaseous fluorine between the stars. That is because the most common interstellar molecule, hydrogen quickly converts fluorine into hydrogen fluoride.

Unfortunately, most interstellar fluorine is probably solid rather than gaseous – locked in minerals in dust grains that leave no fingerprint or stellar spectra. ☻

Source: Excerpt from Sky and Telescope September 2003, pp. 30 - 35, “Flourine: An Elementary Mistery” by: Ken Croswell

Contributed by: Edna P. Azucena

Volume 39 No. 45 3

November Monthly Meeting

Particle accelerators? What is that? Have you ever thought

about it or have you heard of it? In this day and age, no one seems familiar with this high-tech gizmo - even among scientists, except the physicists. No one would care and would bother research on this high-end subject. It’s too technical for an average mind’s grasp or even that of an above-average. But that was the lecture topic last Sunday November 18 during the monthly meeting of the Philippine Astronomical Society held at Rizal Technological University.

And guess what? You might think it’s one of those Einstein-looking geniuses with thick-rimmed eyeglasses who gave the lecture. Nope. Pretty and prim and very feminine in all her beauty-loaded- with-brains combination. Yep. It’s our very own Jenny Baltazar - a PASer and a Board Director who lectured on this topic.

She breezed through the subject of particle accelerators like a kid licking ice cream from an ice cream cone. Boy, did she rattle the neutrinos, fermions, muons, bosons, quarks, etc. like a kindergarten’ s ABCs and a musician’s doremi. Her lecture was well-prepared, very

thorough, comprehensive and well-supported by those colorful visual aids that made the topic less alien to those present.

From Quantum Physics, to governing physical theories and equations, to the structural interior of a particle accelerator, to where they can be found in worldwide laboratories, to the actual modern-day effects of particle accelerators - she covered them all. Very technical indeed, but she managed to lighten the topic for easier absorption and to answer those questions asked by those present for more elaboration.

Why? The particle accelerators have resulted in our televisions, cell networks, computed tomography scannings, positron emission

tomography (ha, more familiar to me now), etc. Ask her and she enumerates more. It’s nice to be able to know how the accelerator works and the physics that explains it all (includes astronomical events).

Isn’t this a big treat to PASers and interested guests? The lecture is free. It upgrades our learning and education. And PASers-lecturers take time from their precious personal time to impart their expertise to fellow PASers.

Let alone the half day each month to get together and to discuss o rg a n i z a t i o n a l concerns.

Thank you, very much, Jenny. Louniza, Regina, Anna, Mark, Danny, Richard, Edna, Agnes, Leah, Liz, Hernan, Leo, Mr.Levy, Marnelli, Jake, Judith and their kid, Ysa were very

happy that you increased our physics awareness several levels up. Thank you too for the usual snacks and the November Appulse copy (well-done, Jake and Marnelli ).

Copies of Jenny’s lecture will be available upon request.

Our endless gratitude to Dr. Jesus Torres for allowing us to hold our meetings at RTU. Ang ganda at ang modern naman ng area where we held our Nov. 18 meeting. ►

4 Appulse - December 2007

Maipagmamalaki.

Oh, I might forget, Frances Taylor (wife of PASer Richard Taylor) also stopped by after the meeting. She and Richard chit-chatted with the group about different topics unrelated to astronomy and astrophysics. It’s an honor for us to have her company briefly on a very casual basis.

The Officers and Board of Directors stayed behind for more discussion on upcoming events and organizational concerns after the Sunday meeting and all others left after the lecture and snacks.

It was a Sunday afternoon well spent. Thanks again, Jenny. And thank you, fellow PASers. See you on November 21 at the Manila Observatory for the Comet Holmes second group observation.☻

Top: Jenny Baltazar giving a lecture on The Standard Modelof Particle Physics and The Physics of Particle Accelerators: Present & Future Effects;

Middle:PASers as they listened to Jenny’s Lecture;

Bottom:Prof. Richard Taylor with his wife Frances.

November Monthly Meeting

Volume 39 No. 45 5

The Philippine Astronomical Society held another comet

Holmes observation last November 21, 2007 at the Manila Observatory, Ateneo de Manila University. Present in the event were Edna Azucena, Vicky Evaretta, Agnes

T. Oclarit, Leo Manosca, Francis

Irlandez, Hernan Dizon, and guests.

Unfortunately, the Comet Holmes observation was rained out. Sayang. Many guests were there including David Schwartz, Ava Tajima, Tomoyuki Hirayama, Mrs. Beth Sto. Tomas and her two kids, Charlene and Catherine, Ernie Ferasa, Jim Cayme, Donna Sanidad, Franz Avila, Genevieve Lorenzo, and specially Dallay Annawi, who we have not seen for sometime and Liz King with her kid Domici Elisa. They were all excited to see Comet Holmes especially that its bigger-than- the sun’s size has been played

up. But rain poured without let up.

Leo assisted by Jake went on with the lectures on Celestial Navigation and How to Set Up a Reflector Telescope. Surprisingly, a six-year-old guest was very interested with celestial navigation and asked for the file to be emailed to

her. Can you imagine that? That’s what I like with PAS public outreach education - it motivates kids to learn and to be really interested in astronomy. The Manila Observatory security officer Ernie was surprisingly very

interested as well. He was all ears during the lectures and now appeared to be knowledgeable in astronomy as well. I heard he has been really involved when observation sessions and lectures were held at the Manila Observatory.

Malas ko talaga. It was my

only chance again to observe with the group but napalpak pa. Same with the lunar eclipse months ago. But I also had the chance to show the binoculars and star map to the Japanese students and the green laser to the Manila Observatory guests who were very excited about the laser’s capability.

Before the lecture started, the guys became kids again as they ran up the roof deck and tried to call our attention by clapping their hands and hollered for us to look up. The group dispersed at 11:00 PM. Edna, Agnes, and I stayed behind and slept overnight on

those comfortable Manila Observatory couches after the usual talks on NAW plans and pizza dinner. We left at 5:30 AM. It was still drizzling then, but who cares. We had a nice time despite the rains.

Special thanks to Mrs. Toni Yulo-Loyzaga and Chinkee Siy.☻

By: Vicky Evaretta

Comet Holmes Observation

Top left: Leo and Liz King’s hands-on during Comet Holmes Observation. Bottom right: Leo conducting a lecture on Celestial Navigation and Telescope Assembly.

6 Appulse - December 2007

Paser’s ColumnA PAS Member’s Memories

When the Planetarium started its operation sometime in 1998 I joined the Philippine Astronomical Society. On Saturdays my department head plus a few friends and I would view stars in the Luneta Planetarium. Vainly I tried to locate Aquarius constellation but I could not.

In 1980, I left for abroad. In my travels I was not able to even schedule a planetarium in Europe and the United States. But in 1965 I had a chance to view an astronomy program in a planetarium in Chicago.

My interest in Astronomy was enhanced in college when I took a course on Natural Sciences 1 under Prof. Robinson. He lectured well but we never gazed at stars as part of the course. It was my first cousin who pointed out Orion, the Great Bear, Taurus, Pleiades, the Little Dipper and Cassiopeia whenever we gazed into the heavens while we were studying in Iloilo.

Astronomy should be taught in the first semester to college students. Why? Because Astronomy opens the door to other branches of science – Physics, Chemistry, Geology, and even Biology. When I became a secondary school teacher, astronomy was just a chapter in our textbook. Ok, we had learned about stars in high school science by Brown and Aldecon (how long was that?) and my science teacher

commended me for having written notes about the Milky Way even before formal classes started during my freshman years.

In time I learned more about astronomy. I bought Astronomy Magazines, Discover, National Geographic Society magazines and even second hand books in astronomy. I even got to understand Einstein’s E=mc² while reading an astronomy article written by an astronomer-scientist in the National Geographic Magazine. It took an astronomer to make me, a layman, understand why stars give off light and that light makes us see things.

I once was invited to talk to public school students who conducted an overnight camp at Mapa High School in 2000. Mr. Sacro was also there as a guest lecturer. My turn came at midnight when the youngsters were quite sleepy. But I saw how interested they became when I informed then – based on some readings – that we are beautiful because our bodies are carbon-based- and not some kind of “monster” had we evolved from a silicon-based organism.

My defining moment as a teacher came when three boys entered a quiz contest in Astronomy by PAGASA in 1998 and garnered the First, Second and Third Prizes. They went on to the Regional level and took the top prize back to Manila Science High

School. Whatever really delighted me was that the boys know more about astronomy than I did at the time the quizmaster was throwing questions for them to orally answer.

I can just imagine how exciting it must be for space travelers to see stars in space. As I train science teachers on how to construct tests in astronomy at Philippine Normal University I motivate them with the mysteries of the universe and the adventures of spacemen who find themselves communing with the Intelligence that designed the Universe. ☻

By: Mounien Beldia, Ph.D

Astrophysics and Cosmology 202Free Lecture Seminarfor Registered Members

For reservations please contact: Phil. Astronomical Society at 4966431 or Mr. Hernan M. Dizon at 0928-4026728 or 4550760

Volume 39 No. 45 7

Merry Christmas and a Prosperous New Year 2008!

BOD and Officers

Text Twister

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8 Appulse - December 2007

Lunar Imagesby John Nassr

A large waxing moon coyly posed for a few pictures last night behind a veil of thin clouds from an impending typhoon.

The 233 kilometer crater, Schickard along the lunar terminator presented an interesting landscape of pockmarked shadows and light. Its highest wall (on the upper left of the main crater) soars to a height of over 8,300 feet.

►

The crater Rosse is only 21 kilometers wide but its rays splash out over ten times that distance across Mare Nectaris. The impacting body that created Rosse clearly came from an oblique angle 1.1 billion years ago.

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▲Copernicus, named after a

16th century Polish astronomer, has bright rays all around and terraced walls along its rim. The impacting body that created the 95 kilometer crater probably came directly perpendicular to the moon’s surface 1.1 billion years ago. Smaller craters Fauth, Reinhold B, and Reinhold are to the upper right of Copernicus.

▲Rimae Sirsalis is an unusual

and very prominent lunar rille stretching over 309 kilometers along the moon’s surface. I was not able to read up on the theoretical cause of the feature but I suspect it might be tectonic in nature. Perhaps someone else could help out with its origin. Craters Billy and Hanssteen are to the left of the rille.

Subtly marking the smooth floor of Oceanus Procellarum are two very ancient craters, Flamsteed P (left) and Flamsteed G (right). They are estimated to be 4.5 billion years old. Their features have been eroded by time even though they reside on a weather-less and windless lunar surface. Though their circular features barely rise from the ancient lava fields of Oceanus Procellarum they can still be distinctly seen in this image.◄

All images were taken under poor seeing and transparency conditions with a C-14 at f11 and a DBK21 color webcam.☻

Photo credits to: John Nassr

Volume 39 No. 45 9

The Sky in January 2008Date event

Jan 01 00:00 New Year Jan 03 16:05 Moon at Apogee (405331 km) Jan 04 14:39 Quadrantid meteor shower at peak Jan 05 13:57 Approaching Minimum Separation of Venus 7° 04’ from Moon Jan 05 14:27 (4866) Badillo is 8° 27’ from (6282) Edwelda Jan 07 18:08 Jupiter is 4° 19’ from Moon Jan 08 19:37 New Moon Jan 09 23:29 Approaching Mercury 0° 17’ from Moon Jan 11 09:15 Neptune is 0° 25’ from Moon Jan 13 09:01 Uranus is 2° 37’ from Moon Jan 15 08:20 C/2005 L3 McNaught is at Perihelion Jan 16 03:45 First Quarter Moon Jan 16 07:16 Algol at minimum brightness Jan 18 14:55 Moon is 1° 08’ from Pleiades Jan 20 07:27 Moon is farthest North (Dec +27° 59’) Jan 20 07:39 Mars is 1° 07’ from Moon Jan 22 13:25 Mercury At Greatest Elongation 19 Degrees East Of the Sun Jan 22 21:34 Full Moon Jan 23 13:37 Mercury Passes 0.35” North Of NeptuneJan 24 15:00 Pluto is 5° 09’ from Venus Jan 25 14:13 Saturn is 2° 57’ from Moon Jan 27 05:30 8P Tuttle is at Perihelion Jan 28 15:13 Mercury is Stationary Jan 29 05:16 (5) Astraea is 8° 50’ from Moon Jan 29 07:22 Moon is 2° 32’ from Spica Jan 29 18:56 (1) Ceres at Quadrature Jan 29 21:36 delta Librae at minimum brightness Jan 29 22:55 (4) Vesta is 3° 10’ from Neptune Jan 30 13:02 Last Quarter Moon Jan 31 05:12 Mars is Stationary Jan 31 12:25 Moon at Apogee (404533 km)

Source: Sky Map Pro

10 Appulse - December 2007

This map shows the sky at 9pm on January 2008 as seen from the latitude of Metro Manila, Philippines with North on top and the zenith at the center. The large circle represents the horizon. Star limiting magnitude is 5.5. Deep sky limiting magnitude is 7.0.

Monthly Star Map – January 2008