Sky Events – Page 51 – A Darker View

Lahaina Noon

Living south of the Tropic of Cancer we get to experience an interesting phenomena that folks outside the tropics will not see. There are two days each year when the Sun passes directly overhead. In the islands this event is called Lahaina Noon.

**Spring Lahaina Noon for 2013**
Location	Date	Time
Hilo	May 18th	12:17pm
Waimea	May 19th	12:20pm
Kahului	May 24th	12:23pm
Honolulu	May 26th	12:30pm
Lihue	May 30th	12:36pm

Lahaina noon occurs twice each year as the Sun appears to move northwards with the spring and again as it moves southwards in the fall. For the islands of the Hawaiian archipelago the first day is between May 16th and May 31st. The second Lahaina Noon will be between July 10th and July 25th.

The date on which this event occurs each year depends on your exact latitude, the further north the later in the spring it will occur. Thus the day for Lahaina noon will vary by eight days from Hilo to Honolulu, and another five to Lihue. As you approach the Tropic of Cancer at 23°26’N Lahaina Noon will occur closer to the summer solstice. The date will also slip a little due to the out of sync nature of our seasons and our calendar. This is the reason we insert a leap year into the calendar every four years.

This year Lahaina Noon will occur on May 18th for residents living in Hilo, or May 26th for Honolulu. It is also important to remember that the Sun is not directly overhead at 12:00 exactly. As the islands lie west of the center of the time zone, true local noon occurs up to half an hour after 12:00.

Asteroid 1998 QE2 to Sail Past Earth

JPL press release…

On May 31, 2013, asteroid 1998 QE2 will sail serenely past Earth, getting no closer than about 3.6 million miles (5.8 million kilometers), or about 15 times the distance between Earth and the moon. And while QE2 is not of much interest to those astronomers and scientists on the lookout for hazardous asteroids, it is of interest to those who dabble in radar astronomy and have a 230-foot (70-meter) — or larger — radar telescope at their disposal.

Asteroid 1998 QE2 Orbit — The orbit for asteroid 1998 QE2 earth approach on 31 May 2013. Image credit: NASA/JPL-Caltech

“Asteroid 1998 QE2 will be an outstanding radar imaging target at Goldstone and Arecibo and we expect to obtain a series of high-resolution images that could reveal a wealth of surface features,” said radar astronomer Lance Benner, the principal investigator for the Goldstone radar observations from NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Whenever an asteroid approaches this closely, it provides an important scientific opportunity to study it in detail to understand its size, shape, rotation, surface features, and what they can tell us about its origin. We will also use new radar measurements of the asteroid’s distance and velocity to improve our calculation of its orbit and compute its motion farther into the future than we could otherwise.”

The closest approach of the asteroid occurs on May 31 at 1:59 p.m. Pacific (4:59 p.m. Eastern / 20:59 UTC). This is the closest approach the asteroid will make to Earth for at least the next two centuries. Asteroid 1998 QE2 was discovered on Aug. 19, 1998, by the Massachusetts Institute of Technology Lincoln Near Earth Asteroid Research (LINEAR) program near Socorro, New Mexico.

The asteroid, which is believed to be about 1.7 miles (2.7 kilometers) or nine Queen Elizabeth 2 ship-lengths in size, is not named after that 12-decked, transatlantic-crossing flagship for the Cunard Line. Instead, the name is assigned by the NASA-supported Minor Planet Center in Cambridge, Mass., which gives each newly discovered asteroid a provisional designation starting with the year of first detection, along with an alphanumeric code indicating the half-month it was discovered, and the sequence within that half-month.

Continue reading “Asteroid 1998 QE2 to Sail Past Earth”

The Moon, Venus and Jupiter

The sunset is getting crowded. This evening will see a trio of the sky’s brightest objects low in the shades of sunset. Venus is still quite low, ony 10.3° from the Sun, shining brightly at -4 magnitude and rising higher each day. Well above Venus can be seen Jupiter, somewhat dimmer at -2 magnitude and 23° from the Sun.

In between the two a pretty crescent Moon is positioned, 4.4% illuminated and about 5° below Jupiter. Tomorrow night will see the Moon above and south of Jupiter with about 7° separation.

This is just the start of a sunset dance that will play out over the coming month. Stay tuned for Mercury to join Venus and Jupiter.

Mercury at Superior Conjunction

Today Mercury passes through superior conjunction, passing behind the Sun as seen from the Earth. The planet will appear in the sunset near the end of the month, reaching maximum elongation on June 12th.

Continue reading “Mercury at Superior Conjunction”

Venus Appears in the Sunset

Venus is currently beginning an evening apparition. This evening the planet should be visible about 10° above the setting Sun. At magnitude -4 it should be easy to spot with a good western horizon. The bright planet will spend the remainder of 2013 in the evening sky, with maximum elongation occurring on Oct 31st.

Tonight also features a pairing with a very thin crescent Moon. The Moon will be a mere 1.3% illuminated and be located 2° south of Venus. A very nice pairing indeed!

Look forward to a number of planetary conjunctions in the coming months. With Jupiter approaching solar conjunction and Venus leaving, the two will cross paths nicely.

Partial Solar Eclipse from Hawai’i

We were all ready to view to eclipse from Keck HQ in Waimea. The gear was ready to go, our astronomers setup to answer questions, the public invited…

It rained.

Not to be deterred I grabbed my little telescope and headed for the Sun. The satellite showed a reasonable possibility of clear skies in Kawaihae. As I rolled into the parking lot at Pu’u Kohala Heiau National Historic Site I found the hole in the clouds needed for eclipse photography.

I was not the first there, I met another gentleman setup with a 70mm Meade ETX, we chatted as I set up beside him. I found out later that a couple of the gals from CFHT were setup at Spencer Beach just below the heiau. For clear skies this was about the only reliable place on the island other than the summit.

I quickly setup my little TV-76mm and got the images I was looking for at maximum. We only got to 47% here on the big island, but still worth the effort to see.

Partial Solar Eclipse Reminder

Annular Eclipse — Jan 15th, 2010 annular solar eclipse, photo by Dan Birchall

A reminder that this afternoon we will have the opportunity to see a partial solar eclipse. For viewers further south, in Australia and across the South Pacific, this will be an annular eclipse. For viewers here in the Hawaiian islands this will be a deep partial solar eclipse, with well over 40% of the Sun obscured by the Moon. This is enough to produce a noticeable drop in the Sun’s brightness at mid-day.

Please exercise caution when viewing the Sun! Use appropriate eye protection or indirect observing techniques to project an image of the Sun. The link at the start of this paragraph leads to a great discussion on viewing the Sun safely. As always the single best source on the web (or anywhere) for eclipse and transit information is Fred Espenak’s eclipse website at NASA. Stop by whenever you have a question on upcoming events as well as viewing and photography tips.

During a deep partial such as this one check out the shadows under nearby vegetation. Small gaps in leaves can act like pinhole cameras projecting small crescent images of the Sun.

Location	Begins	Maximum	Ends	Altitude	Azimuth	Magnitude
Honolulu	14:23	15:48	17:01	43	275	44
Hilo	14:31	15:56	17:05	61	270	47

New Moon

Young Moon — A very young moon over Waikoloa, this is only 26 hours after new, visible to the unaided eye as a sliver in the fading glow of sunset

New Moon will occur today at 14:29HST.

An annular solar eclipse will sweep across Australia and the southern Pacific Ocean. For viewers in the Hawaiian Islands this eclipse will be seen as a deep partial eclipse, with a maximum of over 40% of the Sun obscured.

Continue reading “New Moon”

Partial Solar Eclipse

May 9th will see a solar eclipse sweep across the Pacific. For viewers in Australia and the southern Pacific Ocean, this will be an annular eclipse, not a total eclipse. With the Moon near apogee and further from the Earth, its apparent size will not be quite enough to cover the entire disk of the Sun, resulting in a ring of light surrounding the silhouette of the Moon.

For viewers here in the Hawaiian islands this will be a deep partial solar eclipse, with well over 40% of the Sun obscured by the Moon. This is enough to produce a noticeable drop in the Sun’s brightness at mid-day.

Location	Begins	Maximum	Ends	Altitude	Azimuth	Magnitude
Honolulu	14:23	15:48	17:01	43	275	44
Hilo	14:31	15:56	17:05	61	270	47

Eta-Aquariid Meteor Shower

The early hours of dawn on May 5th will see the peak of the ηAquariid meteor shower. This is a reliable shower that produces anywhere from 30-80 meteors each hour near peak. Resulting from debris left behind by Comet 1P/Halley this shower approaches the Earth from the direction of the constellation Aquarius. As this constellation is quite low in the sky during the shower the meteors are entering the atmosphere at a low angle, this often results in meteors with long trains crossing much of the sky. A good shower that produces great fireballs.

Leonids in Orion — A pair of Leonid meteors streak through Orion

The ηAquariids seem to peak in activity every 12 years. As we are approaching the lull in this cycle it is likely that 2013 will produce a modest showing. That said, meteor prediction is an inexact science, no way of knowing ahead of time how good the shower will be.

IMO analyses in recent years, based on data collected between 1984–2001, have shown that ZHRs are generally above 30 between about May 3–10, and that the peak rates appear to be variable on a roughly 12-year timescale. Assuming this Jupiter-influenced cycle is borne-out, the next trough is due around 2014–2016, so ZHRs should be relatively modest in 2013, according to this idea – IMO website

The ηAquariid shower has a broad peak with several weeks of activity either side of the peak. The entire meteor shower lasts from around April 19 to May 28. Any morning from May 3rd to May 10th can be worth watching with rates to around 30 meteors per hour. The peak itself is predicted for 01:00UT on May 6th (15:00HST May 5th), but this shower often produces subpeaks as the Earth passes through clouds of debris left on successive orbits of Halley’s Comet.

The radiant for the ηAquariid shower does not rise until the last few hours of dark, about 2:30am, making this an early morning observing exercise. 2013 does offer decent viewing conditions, with only a slim waning Moon on the day of peak activity and new Moon occurring a few days later on the 10th. Remember, meteor watching can be enjoyed without any special equipment, just a dark sky and a safe place to watch from. Perhaps a good reason to get out under a dark sky? But then, should you ever need a reason to go observing, just go.