Jane Houston Jones » The Shallow Sky

My first sketch of Comet ISON

jane — Tue, 08 Oct 2013 00:01:06 +0000

Comet ISON October 6, 2013 by Jane Houston Jones

All year long, astronomers have been writing about Comet ISON: will it sizzle or will it fizzle? I was chomping at the bit, waiting for the visual magnitude to brighten enough to try viewing this comet through my own telescope (shown on the right). Finally, the weekend, a dark sky, comet magnitude and perfect weather all came together Saturday night, October 5th and Sunday morning, October 6th.

First, backtrack 16 years. I fondly recall the great comet of 1997 – Comet C/1995 O1, Comet Hale-Bopp, which ruled the skies for 18 months. When it passed perihelion on April 1, 1997, it was brighter than all stars in the sky except for Sirius. With its 50 degree long tails it spanned the evening sky, and was the talk of the town, the water cooler and even led the commute chatter among the passengers in my van pool. Everybody saw it. I sketched it. Astronomy clubs flourished with eager new stargazers. Telescopes were literally flying off the shelf. Then, two years after it faded from view, in April 1999, I observed Comet Hale-Bopp from Ayers Rock in the Australian Outback, through my 12.5-inch telescope, as it scooted in front of the Large Magellanic Cloud. It was over 8 AU/700 million miles away, as far away as Saturn is from Earth. I’ve been remembering the anticipation then the excitement of Hale-Bopp while impatiently waiting for ISON.

Comet ISON’s magnitude is somewhere in the magnitude 10-11? range at the time of my Sunday morning sketch, tho’ all the sources I use show different magnitudes. On October 5, when I observed and made this little sketch these three sources I regularly use show different magnitudes. Magnitude 10.6 here. Magnitude 10.7 here. And magnitude 10 (or even brighter 9.something) here.

So for my observation, I thought it would be more interesting to show the magnitude of many of the the nearby stars I could see in my eyepiece. I used my 12.5-inch f/6.75 reflector and a 19mm Nagler Panoptic eyepiece for a magnification of 96x. Conditions were spectacular, very steady seeing at 5:00 am, and away from the the Zodiacal Light and Milky Way the limiting magnitude had been an impressive 6.5. I was able to see three 14.0 magnitude stars, two very near the comet. I tried higher and lower magnification (over 200x and under 50x) and couldn’t see the comet in any eyepiece over 125x. The sketch shows the comet a bit brighter than it really appeared. It was like an oval puff of barely-there cloud with a brighter condensed area, I assume was the coma. It was much larger than I was expecting. No tail visible. Can’t wait to observe and sketch it again on October 26th despite a big bright moon and November 2nd which should be a perfect moonless viewing night. Until then, I’m looking forward to hearing about more visible reports. Photos are great, but star-stuff hitting your eyes is the best!

Perihelion or bust!

My first view of Comet PanSTARRS 3/11/13

jane — Tue, 12 Mar 2013 09:33:58 +0000

Sunday morning (Sunday March 10) we drove home from a wonderful Amboy Crater observing night. As we drove up our street, we have a good view of Mt. Wilson and the telescopes, as you can see here. My Comet PanSTARRS sketches (and astrophotos tomorrow) from near the Mt. Wilson Observatory (but on the other side of the mountain) are below.

Mt. Wilson 100 & 60-inch telescope domes and solar telescopes from home

I drove past the telescopes on Angeles Crest Highway 2 to catch a glimpse of the comet. From home, Mt. Wilson is about 7 miles away as the crow flies. Not being a crow, I drove 13 miles to work, then 3 miles to Angeles Crest Freeway, then up 20+ miles and 5,200 feet in elevation on the mountain highway to get this view — that’s the historic 100-inch Mt Wilson Hooker telescope dome and the two solar telescopes on the ridge.

Passing Mt. Wilson telescopes from Angeles Crest Highway

We arrived at our viewing location, 23.5 miles up the hill, milepost 48.34, 34d 18′ 26″ N Latitude 118d 00’54″ W Longitude, altitude 5266 ft before sunset – the Chileo turnout just before the Caltrans yard on Angeles Crest Highway. I am indebted to my friend Steve Edberg, who has observed on these pullouts since the 1970′s. We passed many other spots which he has observed from, but which didn’t have the required “dip” in altitude, which provided a view of the western horizon depressed to a further 1 degree.

Sunset (and green flash) at my comet viewing spot on Angeles Crest Highway

We had to wait over a half hour after sunset for the twilight sky to darken. Civil twilight occurred at 7:22 p.m. PDT, when the sun dipped 6 degrees below the horizon. We scanned the sky, not only looking for the comet, but for the moon, too. But the new moon was only about 6 hours old (new at 12:52 p.m. Pacific Daylight Time March 11, and impossible to see). Thanks to Steve Edberg for explaining “horizon depression”:”Due to our elevation, looking down from 5,266 feet, the terrain horizon in the distance was lower than horizontal, so we could look “down” far enough that we gained one degree more of viewing potential. This dip of the horizon doesn’t include the terrestrial refraction at the apparent horizon, which often “raises” astronomical objects (meaning they set later than airless geometry predicts)”.

Here is what we did see, beginning at 7:34 p.m.

Here is my first sketch. Showing what Comet PanSTARRS looks like through 7 x 50 binoculars with a 7 degree field of view. We were unable to see it naked-eye. I couldn’t get both the horizon and the comet in the same binocular field of view.

Sketches show my binocular view - this is what Comet PanSTARRS looked like through binoculars

Here is the final view through bigger binoculars just before the comet was lost in the haze. Celestron 9 x 63 binos, with a 5 degree field of view. It was amazing to watch the speedy comet move!

Last views of Comet PanSTARRS (on first observation)

NASA’s Prime Time for PANSTARRS Toolkit with charts, and observations and more.

What’s Up PanSTARR Edition Podcast

What’s Up in 2013 at a glance

jane — Mon, 07 Jan 2013 18:29:31 +0000

All year long, astronomers have been writing about Comet ISON: will it sizzle or will it fizzle? Both! Here’s my What’s Up video, with December status (written in mid November, but luckily, the comet didn’t completely fizzle)

ISON in December 2013

Comet ISON first spotted by amateur astronomer Bruce Gary and has been imaged by many eagle-eyed observers with good astrophotography equipment since mid August. A selection of images and data are shown here. I’ll update this frequently as more is understood about Comet ISON. Meanwhile, here is a wesbite with current Comet ISON magnitude and location which is constantly updated!

Comet ISON survived its close pass of the sun on November 28. Scientists are unsure what is actually left of the comet. A fragmented nucleus? Nothing but orbiting dust? Stay tuned!

Here’s an excellent Star Chart showing Comet ISON’s path in November, courtesy of Skyhound’s Skytools3 software. (These are the charts I use for my own deep sky observing.) The chart has not been updated for December as of November 30th.

Latest visible comet news here.

December 2013

You may have noticed a very bright ‘star’ in the western sky. That’s Venus! Venus shines at its very brightest, magnitude -4.9 this month. It sets about three hours after sunset at the beginning of the month and one and a half hours after sunset at the end of the month. This is a great month to view the dramatic changes in the apparent diameter and phases of Venus as it races towards its conjunction with the sun. The first observations of the phases of Venus were made by Galileo in 1610!

Mars continues to grow brighter and rises near midnight, and Jupiter rises earlier in the evening, heralding the best viewing season for Jupiter watchers.

The beautiful Geminid meteor shower will only slightly be marred by moonlight on the night of December 13 and 14. The radiant lies near Gemini with brilliant Jupiter above and the constellation Orion below. From a dark sky, but even from the city, the mighty hunter Orion is easily visible in the southeast sky. Take a look at Orion’s shoulder star, red Betelgeuse and its knee star, blue Rigel and the Orion Nebula.southwestern horizon.

The Milky Way and all the visible planets and comets should encourage stargazers to escape the city lights this month. Join me in the California Desert November 30, at MOjave National Preserve. We have no chance to See ISON for another week, but there are other nice comets, planets, stars, and dark sky objects too enjoy from dusk to dawn.

The times to look will be just after dusk, low to the horizon at sunset, and higher at dawn for northern latitudes the first half of the month. On December 1, look for a pretty diagonal lineup of the comet, Mercury and the crescent moon just before sunrise in the southeast. Then for the second half of the month, the comet becomes circumpolar. It will appear near the constellation Draco on December 26th, when it is half an a.u. (0.42 a.u.to be exact) from Earth. Will the comets’ tail span a quarter of the sky? I’ll update this as more info is available.

Jupiter reaches opposition January 4th, 2014, and rises earlier in the evening. Venus bright as it ever gets – a whopping magnitude -4.9. It will be a fabulous view – a particularly good astrophoto and sketching target as it grows in diameter, but shrinks in phase. Mars increases in brightness and rises earlier (after midnight). Mars will be a great target for 2014.

That’s all for this year, I’m Jane Houston Jones

Venus kissed the moon – a daytime occultation of Venus

jane — Sat, 18 Aug 2012 21:41:26 +0000

going

gone!

Venus reappears!

If you were up before sunrise on Monday, August 13th, 2012 you might have seen a very bright “star” next to the moon. As dawn turned to daylight, you could still see that star, or rather, that planet in the daytime snuggled up to the crescent moon.

That planet was Venus, and the moon was about to pass directly in front of it as seen from our vantage point on Earth. An occultation occurs when a solar system body passes in front of a more distant one or a star. Each one is only visible from a certain part of Earth. This occultation of Venus by the moon was only visible over northern Asia and Japan at night and over North America during the daytime.

I set an alarm to remind myself to step outside at about noon on Monday. It was a challenge to find the slender crescent moon, but I had a great view, shielded from the sun by the tall wall of my office building. The shadow helped by boosting the viewing contrast a little, too!

I had no difficulty seeing Venus naked-eye. And for about an hour I held court on the steps to JPL’s famed Space Flight Operations Facility or SFOF for short, and showed a daytime planet to several dozen of my colleagues. At about 1:30 p.m. PDT the moon passed in front of Venus after inching closer for over a half hour.

I was reminded of folksinger Christine Lavin’s lovely song Venus Kissed the Moon from her 1990 album Attainable Love. The lyrics go like this:

Venus kissed the Moon tonight
We watched her in the Sky
She’s been flirtin’ with him for centuries
Too bad he’s so shy
He’s waxing
He’s waning
You don’t see Venus complaining
She’ll steal a kiss whenever she can
Not ’till 2031
Will this happen again

There have actually been several Venus/Moon occultations since Christine wrote this song, but that doesn’t matter. I hummed her sweet song, and watched Venus flirt closer and closer to the moon. I’m listening to it as I write these words, too!

My friend Akkana Peck wrote “If you’ve never seen a Venus occultation before, you’ll be amazed at the difference between the brightness of Venus and the dimness of the moon’s limb. We think of the moon as bright, but it’s actually dark grey, about the same albedo (reflectivity) as asphalt; whereas Venus is covered with brightly reflective clouds.” See Akkana’s images of the Venus occultation and her blog here.

I snapped a few pictures with my hand-held Canon PowerShot SX260 HS with its nifty 20x zoom. I zoomed nearly all the way out for these images.

The next opportunity to see a lunar occultation of Venus from North and Central America will be on December 7, 2015. From Los Angeles, we’ll get to see this event from 7:30 am to 11:30 am.

I’m so glad we don’t have to wait until 2031 to see Venus kiss the moon, Christine!

Counting meteors from Amboy Crater – Lyrids 2012

jane — Thu, 03 May 2012 20:33:50 +0000

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

Viewing meteor showers from light polluted LA – not impossible!

jane — Mon, 09 Jan 2012 05:17:29 +0000

The white area is greater Los Angeles. I observed from my driveway in Monrovia, indicated at the "red/white" border zone marked with cross-hairs

My meteor watching setup - comfortable chair, blanket, clipboard, red flashlights, clock, binoculars, snacks

The graph shows the ZHR (Zenithal Hourly Rate), which is the number of meteors an observer would see under a very dark sky with the radiant of the shower overhead. (this chart is being updated as more reports are submitted)

I prefer to drive far from LA to view meteor showers from a dark sky, but those darn showers don’t always happen on weekends or days I can take off work. So this week, I observed the Quadrantid Meteor Shower from my bright moonlit Los Angeles County driveway until after midnight, snoozed until moonset at 3:00 a.m., then had a fairly decent sky from 3:00 a.m. to 5:15 a.m. when the sky started to brighten from the dawn light. Although I didn’t see many meteors, and only one before the moon set at 3:00 a.m. PST January 4th, I was thrilled with my observations.

Take a look at this colorful map. See that white blob? That’s Los Angeles on a light pollution map. That white ribbon? That’s the California coastline. White on these maps designates the most light polluted areas in the world. There is no worse place for light pollution. LA is the model of a major metropolitan meteor-observing maelstrom of star-obscuring light pollution. This white color on the map is described in bleak terms on the Clear Sky Chart website’s light pollution map page: “The entire sky is grayish or brighter. Familiar constellations are missing stars. Fainter constellations are absent. Less than 20 stars visible over 30 degrees elevation in brighter areas. Limiting magnitude ranges from 3 to 4. Most people don’t look up.” Monrovia is on the north edge of the white blob that is Los Angeles, indicated by the cross-hair. (all those little crosses on the map are other astronomy locations). Red is the next to worst light pollution zone, and the ribbon of red color next to Los Angeles is the San Gabriel Mountain foothills. Monrovia is nestled between the Los Angeles basin and the mountains. It’s fine for moon and planets at our monthly Old Town Sidewalk Astronomy nights, not so good for meteors and anything else astronomical.

The three oval white blobs on the left lower quadrant are Santa Catalina, San Clemente and San Nicholas Islands! The yellow, green and blue zones are in the ocean. It’s even light polluted well off the coast of Southern California!

I usually drive 150-300 miles to one of the black teardrop shaped pin spots on this light pollution map of California. Those are the best and darkest locations for the stargazing and astrophotography we enjoy. Mojo and I prefer Amboy Crater, Hole-In-the-Wall Campground in Mojave National Preserve, and a spot near Desert Center 60 miles past Indio on I-10. We also love the dark skies at Glacier Point at Yosemite.

But this week was the peak of the Quadrantids, and I didn’t want to drive a 6-hour round trip for 3 hours of meteor watching, especially on a work night. So I found a good spot in my driveway and it blocked a lot of the local light sources. I nestled my comfy observing chair up next to a cinder block wall. This wall, plus strategically placed tall trees blocked the moonlight and oncoming car lights from my view. To my south was not the Milky Way, but the milky gray — the color of skies over Los Angeles. I could see the big dipper stars, and part of the little dipper. Below these two constellations was the radiant of the Quadrantids. This area wouldn’t even rise until after midnight, but I wanted to say I observed the Quadrantids during the actual peak, and check for earthgrazing meteors on the horizon.

I estimated my limiting magnitude at a dismal 3.9 using star counting charts. I settled into my meteor-watching chair, sipped some hot green tea and waited. And waited. And waited some more. From 11:00 p.m. until 12:30 p.m (PST) I saw exactly one meteor, and it wasn’t even a Quadrantid. The moon was high overhead now, and so I snoozed until moonset at 3:00 a.m. Wednesday morning.

When my alarm went off, I headed back out to the driveway. I adjusted my chair, adjusted the dark blankets I placed over the fence between my driveway and the neighbor’s all-night security lights. By careful placement of my head, and with blankets on the fences and shrubs I had no lights shining directly at me.

It was a little after 3 a.m. and I started observing an area above the radiant, centered on the bowl of the big dipper. My back was facing the well-lit LA basin, my view to the north was overlooking the San Gabriel mountains and Mt. Wilson Observatory. By 3:18 I had seen my first Quadrantid. At 3:30 I counted stars again. Without the moonlight, my limiting magnitude rose to a respectable 5.1 using this star counting chart. I repeated this exercise several times, until I could barely see stars after 5:00 a.m. My last limiting magnitude calculation before I packed it in was 2.9.

This chart shows the data from 48 observers in twenty countries. Data (still coming in, I’ll update the chart a couple of times) is averaged based on the observers seeing conditions, visual acuity, cloud cover percentage, etc. You can see that the highest rates — at the peak of the Quadrantids were in excess of 80 per hour. This is the number of meteors which would be seen overhead at the zenith (in a dark sky) if the highest rate was kept steady for one hour. In reality, the highest rates last usually for only a few minutes for showers like the Quadrantids with a very narrow peak. How many did I see from my Monrovia driveway? I saw three from 3:00-3:30 a.m. and another three from 3:30-4:00 a.m. I saw five from 4:00 to 4:30 a.m. and between 4:30 and 5:00 a.m. I saw three, plus heard nearby roosters crowing! I finished the observing with 2 more Quadrantids between 5:00 and 5:15 a.m. and was heralded by a veritable rooster symphony as the sky brightened. My total count over a little more than 2 hours was 16 lovely Quadrantids, two sporadics, and one Anthelion! Here’s my report which I submitted to the International Meteor Organization. Amazingly, this number is almost exactly the prediction from NASA’s Meteor Fluxtimator when I entered Quadrantids from downtown Los Angeles on the 3rd and 4th of January 2012. How about that! You can observe a meteor shower from Los Angeles!

Here’s the meteor shower calendar for 2012

Interested in counting meteors? Here’s the IMO Visual meteor observing form plus instructions and FAQs

More about the Quadrantids and their namesake constellation, Quadrans Muralis

Post-Perseid depression (or how to observe meteor showers)

Perseids from Amboy Crater (a dark sky site)

Watching asteroids fly by

jane — Fri, 11 Nov 2011 00:40:28 +0000

It was 23°F inside the observatory while we were observing the asteroid

Asteroid 2005 YU55 sketched November 8, 2011

Asteroid 2005 YU55 wasn’t my first visual observation of an asteroid passing near Earth, but preparing to view it brought back some great memories of our first one, asteroid 2002 NY40, nearly ten years ago.

Here’s a little writeup about both observations. First up, Tuesday night’s observing of Asteroid 2005 YU55. It’s 400 meters (1,300 feet) in diameter. On November 8, 2011 it passed 0.85 lunar distances (324,600 kilometers or 201,700 miles) from the Earth. It has been studied by radar using NASA’s Deep Space Network’s Mars Antenna in California’s Mojave Desert. The Herschel Space Observatory took some measurements in the far-infrared. The Swift Telescope observed it, too. Oh, also legions of amateur astronomers imaged, sketched and observed this “once in-a lifetime” event, including me!

Tuesday afternoon, I drove 100 miles to a friend’s private observatory near Mt. Pinos. I knew as soon as I looked at the sky that I’d never find the asteroid in my telescope. The near full moon wiped out all the fainter stars I’d need for star-hopping to the asteroid. It was 30°F upon arrival, snow on the ground, and it got colder as soon as the sun set – to a low of 23°F.

After an hour, Steve, the owner of the observatory found asteroid 2005 YU55. He was stunned at the movement as it zipped across the eyepiece view. Three of us took turns stepping up a ladder to reach the wide field eyepiece atop his 14-inch reflector. The 1 degree field of view in the eyepiece we used is equal the apparent diameter of two side-by-side full moons. We took turns watching the faint asteroid move for about a minute or two, then letting the next person have a look. It took the asteroid about 9 minutes to traverse the eyepiece field. My sketch shows the asteroid’s motion in about 2 minutes, and this star chart gives you an idea what the we saw in the sky and in the eyepiece.

You can see the constellation Pegasus high overhead on the star chart. That’s where we were aiming. As we tried to follow the faint asteroid in the eyepiece, we each made a triangle out of slightly (magnitude 9 and 10) brighter stars which the 11th magnitude asteroid would pass by. That way we had fixed objects to anchor our view of the motion.

This was no glittering diamonds on black velvet view. The nearly full moon was right next to where we were looking, and it brightened the sky and the ground. Only the brightest stars were visible. “It was a fast-moving ghost against other fixed ghosts in the moonlit background sky”, described Steve. I saw a grey poppy seed moving against a grey felt sky. It made us gasp in amazement that we were looking at it with our own eyes, especially since it was so small and so faint! After an hour or so of viewing, we packed up and headed back home, 100 miles away.

Now, here’s a little trip down memory lane for me – my first asteroid flyby on August 17, 2002.

On August 17 and 18, 2002, Asteroid 2002 NY40 zipped past Earth 1.3 lunar distances – 530,000 kilometers or 330,000 miles away. From 9:30 to 10:30 p.m. on August 17th our deck in suburban San Rafael, CA was filled with telescopes. We invited astro friends over for a spur-of-the-moment asteroid party, gambling that our inland location would be fog-free, unlike many of the usual astro spots.

After a quick dinner, a dozen of us stepped out on the deck. Mojo was the first to spot the swift 9th magnitude asteroid 2002 NY40 in his 14.5-inch f/4.8 LITEBOX reflector. Our friend Jim also found it in his 8-inch LX-10. Our friend Stacy was happy to spot the moon in her new 10-inch dob without a finder. For a good hour we kept the asteroid in Mojo’s scope. All our pals got to see the asteroid whiz through the field of view several times through two telescopes.

Both observations were amazing. You can always go back and look at videos and images, but you only get one chance to see celestial events like these with your own eyes. And I plan to try and observe every once-in-a-lifetime event that I can.

Nasa JPL Press Release about the November 8th close flyby of 2005 YU55

Nasa Science News about the close flyby of 2002 NY40

Solar System, Milky Way, Local Group, Extragalactic observing

jane — Mon, 31 Oct 2011 02:10:56 +0000

Comet/2010 G2 (HILL)

NGC7380 emission nebula and cluster

The Great Galaxy in Andromeda, M31, with M32 and M110 nearby

The Pegasus 1 galaxy cluster

I love to take my telescope out to observe the sky, and I find that the objects studied or discovered by scientists (from the past or the present) make for an even more rich observing (and learning) experience. Here are just a few observations from a fantastic night at Amboy Crater October 22, 2011. Amboy Crater is well worth a visit for daytime hikes as well as for spectacular stargazing at night.

IAU circular No. 9134, issued on 2010, April 11, announced the discovery by R. E. Hill of a new comet on Apr. 10, 2010, in the course of the Catalina Sky Survey. After posting on the Minor Planet Center’s NEOCP webpage, many observers checked out this 19.5 magnitude object, designated C/2010 G2 (HILL). (HILL) is well known and well respected Rik Hill of the Lunar and Planetary Lab at University of Arizona, Tuscon. He literally wrote the book about observing sunspots for the A.L.P.O. Sunspotter program. I used this book to sketch sunspots and complete the ALPO Sunspotter program last solar maximum in 2002, and I encourage you to complete this amazing program now, as solar maximum is coming up! I observed Rik’s comet on October 22, 2011, when it was magnitude 10.78 and 1.5 AU distant from Earth. It was small, the coma diameter was 6.2′ – and it was very hard to find! Here’s Mojo’s lovely image from that night. In the eyepiece the green color was absent, in fact it was nearly a no-see-um! Here’s a finder chart. Now, off to explore the Milky Way.

NGC7380 is an open cluster sometimes referred to as the Wizard Nebula located in the constellation Cepheus. It’s about 7,000 light-year away from Earth. The stars of NGC7380 have emerged from the star-forming region in the last 5 million years or so, making it a relatively young cluster. Here’s the image from NASA’s WISE Mission of NGC7380 in 2010. It’s a mosaic of images spanning an area on the sky of about 5 times the size of the full moon. Caroline Herschel discovered this cluster on August 7, 1787 when her brother William Herschel was away in London. She discovered many objects, include comets on the nights she was not recording William’s famous observations. Let’s check out a galaxy in our local group now.

Everyone with a telescope observes the great Andromeda Galaxy, M31 as soon as convenience and sky conditions allow. It’s the largest galaxy of our galactic family, the Local Group, which consists of not only the Andromeda Galaxy, and our own Milky Way galaxy, but also the Triangulum Galaxy, M33, and about 30 other smaller galaxies. It’s visible with the unaided eye if you know where to look from a dark sky. It’s magnificent in binoculars, and unsurpassed in a telescopic view, no matter how big or small the telescope might be. Here’s the image from NASA’s Spitzer Space Telescope which studied our neighbor galaxy. Mojo reprocessed this image a week later. Now let’s move out beyond our local group and check out something extragalactic.

Perseid 1 Galaxy Cluster is 250 million light years distant. It’s not in the local group! The brightest members are a pair of magnitude 11 elliptical galaxies — NGC7619 and NGC7626 — which you can see in Mojo’s first image from October 22. Here’s a fascinating (and local) report on NGC7619 by Mt. Wilson Observatory’s Milton Humason written in 1929. In the early twentieth century, the construction of big telescopes at Mount Wilson (the 60-inch and 100-inch) allowed astronomers to determine the motions of galaxies for the first time.

Milton Humason used the 100-inch telescope on Mt. Wilson. He writes “During the past year two spectrograms of N. G. C. 7619 were obtained with Cassegrain spectrograph VI attached to the 100-inch telescope. This spectrograph has a 24-inch collimating lens, two prisms, and a 3-inch camera, and gives a dispersion of 183 Angstroms per millimeter at 4500. We present new observational results of NGC 7619, an elliptical galaxy with a prominent X-ray tail and a dominant member of the Pegasus group”.

More recently, Chandra and XMM-Newton observations confirmed the presence of a long X-ray tail on NGC7619. I love seeing objects our space telescopes study and image! And I often spend many enjoyable hours learning the science behind my stargazing targets when I’m back at the armchair.

Here is Mojo’s blog + photos from October 22 at Amboy Crater.

Here is Mojo’s blog + photos from October 29 at Red Cloud Road.

A Month of Moon Views

jane — Mon, 12 Sep 2011 23:22:07 +0000

Lunar Landing Site Chart - click for larger versions. Courtesy Lunar and Planetary Institute

My photo of a three day moon. East is at the bottom. Mare Crisium is the egg-shaped feature on east limb.

Here's my photo of a five-six day moon, near first quarter. East is at bottom here too. The middle sea visible above/West of Mare Crisium is the Sea of Tranquility, site of the Apollo 11 landing.

Here's my photo of a fourteen day or full moon. East is at the top. Notice the features are less distinct, but look for the long rays spreading out from the two large craters Copernicus (lower middle left) and Tycho (lower right).

Finally, my photo of a 21 day or third quarter moon. West is at the bottom left

Fasten your seat belts. I’m going to take you on a guided month-long tour of the moon and highlight some of my favorite lunar features. You can use this travelog all year to observe or sketch the moon any time the moon is visible. You’ll be surprised how some of the familiar geology you’ll see on our rocky neighbor changes as sunrise or sunset illuminates different sides of crater walls. If you don’t have a moon map, click on the one to the left, or the other one at the bottom.

The visible features I describe will be illuminated by sunlight from the right to the left as shown on this moon chart. It takes 14 days from new to full moon. At full moon the entire disk will be illuminated, then sunset darkens the features night by night, from right to left. Try viewing the same features before, during and after the full moon.

New Moon Phase Day 1 – 6 The moon rises at dawn, and sets at dusk. The new moon phase starts at solar conjunction. This is the starting point of the lunation or period of the Moon’s cycle around the sky. Day 1 is very difficult to observe. On day 2, the “sea” of Crises, Mare Crisium becomes visible. To the south is Petavius, a large crater with a central peak of over 8000 feet. Day 3 brings Mare Fecunditatis, south of Mare Crisium, into view. On day 4, Mare Crisium and Mare Fecunditatis are fully visible, and the walled plain Janssen is visible. On day 5, Theophilus, Cyrillus and Catharina make a nice group of craters. The crater Maurolycus, with a central peak like Theophilus, appears on day 6. The moon is now approaching first quarter. The terminator (boundary between the sunlit and dark parts of the moon) is now at the center of the moon’s disk.

First Quarter Phase Day 7 – 13 The moon rises at noon, and sets at midnight. The crater Hipparchus is at its visible best near the terminator on day 7. Look for two craters within Hipparchus. Day 8 brings into view the rugged Appenine mountains, and to the north the oval walled plain Plato. With binoculars or telescopes, find the “Straight Wall”, a lunar fault line. Tycho and Copernicus are on the terminator on day 9, and so is Clavius, the large walled plain south of Tycho. On day 10 look for the Jura Mountains and Sinus Iridum (the bay of rainbows) with its hook-like curved mountainous point on the edge of Mare Imbrium. This is one of my favorite objects on the moon to observe and sketch. On day 11, look back on the whole moon and observe the dark lunar lava plains divided by mountains. On day 12, look at Gassendi, a large crater with a smaller crater next to it. Together they look like a diamond ring. As full moon approaches, look back over the objects you observed each night and see how different they look.

Full Moon Phase Day 14 – 21 The moon rises rises at dusk, and sets at dawn. Look at the bright ray systems. The direct sunlight on the moon at this phase washes out features, and you see no shadows, just like when the sun is directly overhead on earth. The long rays of Tycho are most dramatic at full moon! Day 15 brings sunset to Crisium, 2 weeks after we first viewed its sunrise. Watch the shadows cast on the walls of the plains including the darkened Mare Crisium, and craters on day 16 through 18. Day 19 is a good one to view the “Sea” of Tranquility, famous as the landing site of Apollo 11. There is a link to lunar landing sites at the bottom of the page, by the way. Day 20 brings the terminator to another of my favorite observing and sketching sites, the three craters Theophilus, Catharina and Cyrillus. Mountains are the highlight of day 21. The Apennines, and the large craters Kepler, Copernicus and Tycho are beautiful at lunar sunset. The last quarter moon has arrived.

Last Quarter Moon day 22 -27 The moon rises at midnight, and sets at noon. You really have to be dedicated to view this phase, or maybe just sleep deprived. Mare Imbrium and Copernicus are darkening on day 23. On day 24 through 27, most observers are sleeping when the moon is visible. Use binoculars to observe earthshine over the surface of the moon. These are the days (or rather nights) to turn your eyes, binoculars or telescopes to other wonders of the night sky: planets, comets, meteor showers and galaxies. Say good-night to our close neighbor. If you didn’t catch all these features, there’s always next month!

A moon map with almost all the features labelled

Check out all 6 Apollo landing sites, plus moon phase/landing site maps on this flyer I made for the GRAIL mission launch week in September 2011. (PDF)

USNO’s great Phases of the Moon and Percent of the Moon Illuminated pages

Here’s the original 1990 article I wrote for John Dobson’s Sidewalk Astronomy newsletter. My mom contributed the adorable lunar drawings.

My Sketches at the Eyepiece website

Meteor observing tips – updated old blog for 2015

jane — Wed, 31 Aug 2011 22:29:37 +0000

My meteor shower first aid kit

Waiting for moonset on Perseid night 2010, observing from Amboy Crater, CA

Notice elevated rates from August 7th-15th, and a secondary peak on the 17th, and the 20th?

Here’s what you can expect to see from a dark sky observing for several hours like the 2010 Perseids which peaked on a moonless night like this year.

I enjoy observing meteor showers from the darkest sky I can drive to in one night. Here’s where I go, what I bring (and don’t bring), and how I observe.

You will want a comfy chair that supports your neck. I bring a clipboard with blank sheets of paper and Finnish Triangle limiting magnitude star charts to determine my limiting magnitude throughout the night.

I also pack binoculars, but not for observing meteors. I just like to have them with me to look at galaxies and star clusters when not counting meteors. I leave my telescope at home, too. I bring a digital clock that doesn’t emit any light, a red flashlight, pencils, an audio recorder, and a cooler full of snacks and water. I keep on hand layers of clothes, a blanket or sleeping bag, and hand-warmers for cool nights. For comfort, I carry a first aid kit including eye drops, chap stick, and sting-ease for bug bites. One more thing I keep handy – a piece of string, in case I want to trace a meteor to its radiant by holding it up to the streak of light.

I don’t keep any light emitting devices within eyesight – no cell phone, no interior car lights, no telescope mounts or cameras that emit or blink light. You don’t have to be that drastic about darkness, but I often drive a long way to a dark sky and want to see faint meteors. Any car or phone light will ruin my dark adaptation. It can take up to an hour for your eyes to adjust again. If a car or a friend stops by, I will just take a break, or shut my eyes until the light is gone.

Once I am ready to begin observing, I scan the area of the sky I plan to watch. Note! You don’t have to look in the direction of the radiant. The Perseids all appear to radiate from (fly out of) a point – the radiant – in the constellation Perseus, and so they will appear everywhere. That’s where the string or shoelace are helpful — to trace the meteor back to its point of origin. Then I memorize the magnitudes of familiar stars nearby so I can accurately note the meteor magnitudes on my observing paper – one sheet for every 15 minutes I plan to observe. The info all ends up on this visual observing form, prepared from all the raw data. Then I sit in my comfy chair, clipboard on my lap, and wait for that first meteor to streak across my viewing field.

2015 Perseids – Live updates!

My accounts of the 1998-2002 Leonid Storm Multi-Instrument Aircraft Campaign (MAC)

My account of the 2007 Aurigid Outburst, Perseid MAC

2011 Draconids MAC