Observing near the summer solstice means a short observing night sandwiched between a late sunset and an early dawn. Rather than rush through an observing project I find it’s a great time of the year to sit back and trace familiar constellations in my [...]]]>

Summer Milky Way, Scorpius and dark nebulae, image by Morris Jones

Observing near the summer solstice means a short observing night sandwiched between a late sunset and an early dawn. Rather than rush through an observing project I find it’s a great time of the year to sit back and trace familiar constellations in my minds eye, and marvel with anticipation as the eastern horizon brightens. Soon, the stars of Scorpius and Sagittarius will rise and the “clouds” on the horizon take shape as lumps and glittery clusters, bisected by dark nebulae — those mysterious star-less regions within our Milky Way Galaxy.

It’s hard not to just sit and gaze at the unfolding spectacle. So for the first hour or two after darkness last Saturday night (June 16, 2012) I sat in my meteor observing chair and observed the sky with my own eyes. Every now and then I jumped up and eyeball-aimed Mojo’s 15-inch Litebox reflector at this cluster or that nebula. The sky conditions at Amboy Crater were near perfect.

We have 360 degree perfect horizons at this site, with small light domes from 29 Palms, and from departing trains. Temperatures are warm with just a hint of breeze, hot before sunset, shirtsleeve observing all night long, humidity 10% rising to 20% at dawn. Conditions are dry and warm. No dew. Ever! Here’s the Clear Sky Chart for Amboy Crater.

Lyra

Ophiuchus and Poniatowski's Bull

the demoted constellation Poniatowski's Bull and Ophiuchus

As I was looking at the constellation Lyra and its gem-of-a-telescope-target, the Ring nebula, M57, I spotted an asterism nearby, in the northeastern section of Ophiuchus that looked just like Lyra, except it was upside down.

That looked like a good place to select an observing project, so I cracked open my copy of the Night Sky Observers Guide, volume 2 Spring and Summer to the constellation Ophiuchus. I noticed this little group of stars that looked like Lyra were part of an open cluster, and that there was another pretty cluster in the neighborhood.

Best of all, Barnard’s Star was within the cluster! Barnard’s Star is the second closest star to the Earth — only 6 light years away, shining at a faint magnitude 9.5. The Alpha Centauri system, including Proxima Centauri, together are about 4 LY away, but we can’t see them from the US. Barnard’s Star has the greatest proper motion — the angular annual movement across the line of sight against the distant stellar background of any star. It moves 10.4 seconds of arc per year. That compares to a quarter of a degree in a human lifetime, roughly the angular diameter of the full Moon.

Amateur astronomers, carefully sketching or imaging Barnard’s Star once a year for a couple years can actually track the movement of the star. It’s a cool red dwarf. And it’s listed in Jim Kaler’s fabulous book The Hundred Greatest Stars. Jim writes “Barnard’s Star has a metal content only 10 percent that of the Sun. That coupled with its high velocity shows it to be a special, rather rare, kind of star called a “subdwarf” that more belongs to the metal-poor and ancient halo of our Galaxy (the Sun belonging to the disk). It is merely passing through our local neighborhood.”

You’ll definitely need a star chart to find it. Here’s one showing Barnard’s Star within the Melotte 186 star cluster with pretty IC 4665 nearby. This tiny faint red dwarf is a challenge, but it’s worth it, as are the two clusters.

The neighborhood it’s passing (to our line of sight), is through the demoted constellation Poniatowski’s Bull. This V- shaped set of stars looks like a bull’s head and horns in northeastern Ophiuchus. I see Lyra, instead, by adding a few other stars. It was named Poniatowski’s Bull (Taurus Poniatovii), to honor Stanislaus Poniatowski, King of Poland from 1764 to 1795. Named by Polish-Lithuanian astronomer and mathemetician Marcin Odlanicki Poczobutt whose observatory at Vilnius gained royal favor from the King.

So now, when you are looking at our Milky Way, notice Vega and her constellation Lyra. Then turn your head ever so slightly to the right, and you’ll see huge Ophiucus, which looks like a big percolator coffee pot to me. It’s above and between Scorpius and Sagittarius. The left star of the “lid” of the coffeepot is part of my “upside down Lyra”.

Nothing beats visual astronomy. Without taking the time to sit down and just look at the sky, and trace the constellations I never would have discovered this lovely demoted constellation for the first time!

There is always something to observe that you’ve never seen before, even if it is the same old stars. That’s what makes visual astronomy my go-to hobby. Pun intended!

Mojo’s images and writeup from the same night: predawn planets & astrophotography

More Fast Moving Stars

More Demoted Constellations

Early morning hikes – the Chuckwallas of Amboy Crater

2012 Lyrid Meteor Shower Meteor Profile showing peak near 04h-06h UTC

My visual meteor observing report with 30 minute (or less) intervals, and magnitude distribution

Saturday night, April 21, Mojo and I headed to our new favorite dark sky spot, Amboy Crater, one of the darkest observing locations in the US. [...]]]>

Amboy Crater at dawn

2012 Lyrid Meteor Shower Meteor Profile showing peak near 04h-06h UTC

My visual meteor observing report with 30 minute (or less) intervals, and magnitude distribution

Saturday night, April 21, Mojo and I headed to our new favorite dark sky spot, Amboy Crater, one of the darkest observing locations in the US. This spot has great horizons and its remoteness keeps all but the serious observers away, though we’ve met delightful observing buddies at this spot. Our one way drive from Monrovia, CA is 170 miles, fyi.

After a night of observing, you can’t beat the morning hike to Amboy Crater, a 6,000 year old volcanic cinder cone, either. Even in the summer it’s cool at dawn. Look carefully at the oxidized lava beds as you follow the hiking trail to the crater and you might find some Chuckwalla lizards! Chuckwallas can reach 16 inches in length, weigh up to 2 pounds and are specially adapted for desert living. Chuckwallas are my very favorite herps, well, next to the desert tortoise, that is.

The peak of the Lyrids occured at 1:30 a.m. Eastern (10:30 Pacific). The constellation Lyra was barely above my horizon at that hour. This meant the highest rates were probably recorded several time zones east of my California location. I set up my observing area, shut my eyes until about 11:00 p.m., and then I managed to observe straight through the night — from 11:40 p.m. until just before dawn at 5:16 (6:40h – 12:16h UT).

Here are a few tips I use to prepare myself for a night of meteor counting. First, I read Bob Lunsford’s weekly meteor shower recap on the Yahoo meteorobs group email list which discusses amateur meteor astronomy. It’s a good place to “lurk” and learn.

Bob wrote “The Lyrid (LYR) shower is expected to reach maximum activity on the night of April 21/22 with rates up to 15 shower members per hour. The radiant is located at 18:08 (272) +33. This area of the sky is actually located in extreme eastern Hercules, eight degrees southwest of the brilliant blue-white star Vega (Alpha Lyrae). The radiant is best placed just before the break of dawn when the radiant lies highest in the sky. While Lyrid meteors can be seen in both hemispheres, the north is favored as the radiant lies much higher in the sky. Rates will fall rapidly after maximum and little activity will be seen the remainder of the week. At 48km/sec. the Lyrids would produce meteors of medium-swift velocity. It should be noted that the Lyrids can occasionally produce bright meteors of fireball class magnitude.”

Next I familiarized myself with the spring sky and printed out some all-sky charts, marking the radiant between Lyra’s bright star Vega, and the Keystone section of Hercules. I then decided where to look — 50-70 degrees above the horizon, 20-40 degrees away from the radiant. I selected the area around the bright star Arcturus in the constellation Bootes. When counting meteors you don’t want to look directly at the radiant as the meteors will look like short streaks, or points of light.

For this shower the rates were not expected to be too high, so I decided to record (for my first time) the magnitude of each meteor. I made a note of the magnitude of Saturn, Mars and Venus and re-familiarized myself with the magnitudes of many bright stars nearby during my prep time. Then, I selected two small constellations (Corona Borealis, and the head of Draco) which contain magnitude 2-5 stars and memorized their magnitude.

Armed with all these stellar magnitudes, I settled down and waited for it to get dark. Once it did, I began the first important observation — estimating the limiting magnitude. The limiting magnitude is the magnitude of the faintest star near the zenith that the observer can detect using the slightly averted naked eye. It defines both the condition of the sky’s clarity and the quality of the observer’s eyes. I keep a set of these charts on a clipboard and take them with me on all observing trips, even if I am not observing meteors. Every 30-45 minutes, between my half-hour counting sessions, I re-counted the stars in the selected areas, to note any changes in the sky clarity or the condition of my own eyes.

In a nutshell my skies were Magnitude 6.5, which is very dark. Weather conditions: clear, 98 degrees at sunset, 62 degrees at dawn. It was a shirtsleeve weather night almost all night long, tho’ I put on a fleece jacket at about 4 a.m.

Between 11:40 p.m.and 5:16 a.m. (06:40h – 12:16h UT) I counted 36 Lyrids, 6 Sporadics and 2 Anthelion meteors. A quarter of the Lyrids I saw were very bright -1 or brighter meteors. I took short breaks between counting sessions to re-estimate the limiting magnitude, have a snack, check on what Mojo was imaging through his telescope, stargaze through my own scope, etc.

06:40h-07:10h UT – 7 Lyrids
07:30h-08:00h UT – 3 Lyrids
08:15h-08:45h UT – 5 Lyrids, 1 sporadic
08:50h-09:20h UT – 5 Lyrids, 1 sporadic
09:30h-10:00h UT – 6 Lyrids, 2 sporadics
10:05h-10:25h UT – 1 Lyrids, 1 sporadics, 1 Anthelion
Break to look at Saturn, have a snack, scan Milky Way
10:59h-11:29h UT – 2 Lyrids, 1 Anthelion
11:30h-12:00h UT – 7 Lyrids (2 fireballs!)
12:01h-12:16h UT – 1 sporadic

You can see that I saw the most meteors just as I was getting started (which was near the peak) and again near dawn (when Lyra was at its highest in the sky). Just before 5 a.m. 12h UT both Mojo and I saw a very bright bollide, greenish in color in the western sky. I estimated its magnitude at -5, brighter than Venus. It probably was much brighter. Coincidentally, 3 hours later an even more impressive bollide streaked across the California Sierra foothills, and broke up in the atmosphere, sprinkling meteorites over a wide populated area. Both of these bollides were Lyrid fireballs!

My other Meteor blogs and adventures

Flying through the Leonid Storm of 1999 – aboard USAF’s ARIA from Edwards AFB

Leonids 2002 – aboard NASA’s DC-8 from Dryden Flight Research Center

Observing meteors from the city – yes you can!

My meteor observing gear

January Quadrantids and a demoted constellation

August Perseids and meteor recording tips

Lyrid 4/22/12 fireball movie with radiant map

Mojo’s astrophotography from Lyrid shower night