Sunday, April 26, 2009

Event Horizon at Deepsky Ranch

By 11, the first dark cloud appeared over the western horizon, low, flat, long, and dark. We knew what it meant. I knew it that afternoon, looking at the skies with my friends, when we met in Morgan Hill for the drive. The sky was thick, gloppy, Fremont Peak to the south a mere suggestion of a silhouette, no detail. All we could do was hope.

The drive, this time, blew by in a blur of quick glimpses. Part was due to speeding, but mostly it was an active internal dialogue - I was totally distracted.

A quick stop in Paicines waiting for others to catch up, I stood looking at the fields of green onions and grape vines, my mind still racing through personal history. I was hardly there. I missed all the scenery, and suddenly found myself turning onto Antelope Valley Road and into Willow Springs.

Willow Springs is almost not there. It is not a place name you find on any maps, just on the entry gate. It is a place where a few friends meet, once or twice a month, and almost literally leave the world behind. It is called Deepsky Ranch for a good reason, as there lives Dobzilla, the beastly 33.4" f/5 Dobsonian telescope. Even the 22" there that night, looked like a toy next to it.

We sat around for a while in the chill breeze, sipping a bitter Torpedo Ale, waiting for the crew to arrive. Soon we were all on board and began setting up or equipment.

At sunset, I was already in most of my cold weather gear, but the soles of my feet were chilled. Good news was, the jet contrails were short. Bad news, it was cold, and the air was still thick. In the east, the purple edge of night was rising, and the west showed a very thin sliver of a moon a few degrees above the horizon, and Mercury at its greatest elongation eight degrees further up the ecliptic, shining brightly at almost mag 0, fat at almost quarter phase. It was almost too bright and easy to see, to believe it was Mercury.

As soon as dark was upon us, the crew began in earnest at their telescopes. There was quite a bit of discussion about a new ultra-fast 22" that was nearby, but other than that, conversation revovled around occasional "hey... come look at this" sorts of invitations.

The evening continued that way until about 11, when the first dark cloud appeared over the western horizon, low, flat, long, and dark. We knew what it meant. As the property owner had predicted, the moisture content had begun to condense. Soon, the entire western horizon was dark - black bottom clouds, a testament to the darkness of Deepsky Ranch.

The race was on. I had been observing targets off a list I'd put together, mostly Arp galaxy pairs and (rather poor) Abell Galaxy Clusters.

To me, the best view of the night was NGC 4565 in the new 22". It had a huge wingspan, the dark lane was nearly photographic, and the small bright core stood clearly on one side of the lane. Great view.

With the approaching wave of moisture I abandoned the list, and began racing through the big and bright, as if to gather as many photons as possible before the stars went away. M3, M13, M 92, M51....

And it was done. The edge of darkness hung over us at zenith like a crashing wave. To the north and south it began closing in. Spots of darkness began to appear overhead further to the east. It felt like we were skirting some sort of event horizon... another 30 minutes, and the universe would appear to disappear. Indeed, the clouds were an ending horizon for our event.

We thought about how wet everything would soon get, packed, and by 12:30 I was on the way home. I saw no more of the scenery on the way back than I did getting there. My mind was racing, but this time, at night, I was driving cautiously, on the winding roads home from Darksky Ranch.

Here are my notes from the night. Telescope, 18" f/4.5 Obsession, using a 20mm Nagler for finding, 7mm Nagler for scrutiny, and sometimes a 12mm Nagler.

AGC 1767 UMa GXCL 20.7' 15.7 13 36.00 59 12 00 MCG+10-19-96
18" 7mm - observed MCG +10-19-96, MAC 1336-5911A, MAC 1336-5911B, MAC 1335-5913.

AGC 1691 CVn GXCL 19.0' 15.4 13 11 24 39 12 00
18" 7mm - most are very dim averted only. MCG +7-27-39, MCG +7-27-42, MAC 1311-3917, 1311-3916A, 1311-3916B

Arp 40 CVn GX 0.8'x0.5' 15.8 13 29 21 37 24 49 IC 4271
18" 7mm - galaxy is dim but obvious, elongated NNE/SSW, no detail, even brightness across. Dimmer galaxy visible about 6' EESE, no detail slightly smaller

N4914 CVn GX 3.5'x1.9' 12.5B 13 00 42 37 18 54
18" 7mm - elongated NNW/SSE about 3'x2' in size. Bright stellar nucleus in an elongated core. 20mm also shows N4868 and N4893 in same field.

NGC5033 CVn GX 12.4'x5.0' 10.8B 13 13 28 36 35 28
18" 7mm - elongated N/S, bright, 5'x1' with a bright elongated core and a distinct pinpoint nucleus. Star at N end of galaxy, possible bright knot on W edge of S side. Holmberg VII is nearby, large but smaller than N5033, dim, amorphous but elongated. Required averted.

Arp 265 CVn GX 1.4'x0.6' 15.1 12 53 53 36 05 10
IC 3862 18" 7mm - extremely faint, elongated slightly W of N/S. No detail, indistinct. Small.

NGC5273 CVn GX 2.7'X2.4' 12.4B 13 42 08 35 39 19
18" 7mm - nearly stellar nucleus surrounded by round brighter core, dim almost round halo extends to about 3'x3'. Just E is N5276, elongated NW/SE and slightly smaller, very little detail.

N4956 CVn GX 1.5'x1.5' 13.3B 13 05 00 35 10 40
18" 7mm - small, mostly round with possible slight elongation WWSW/EENE, bright nearly stellar nucleus in pronounced core. Core is surrounded by small halo.

Sunday, April 19, 2009

Outstanding Night at Dinosaur Point

Saturday April 18th was one of those days the astronomy gods smiled on. You can't tell when you'll get one. Sometimes there can be an entire observing season full of them. Then they can disappear for years. A friend once equated observing to skiing, saying conditions make all the difference. A great day skiing is memorable, like a great one observing. Saturday night was a very good one. The combination of very good seeing, transparency, little wind and warm temps made it about perfect.

Even the drive there, for those of us who beat the accident on 152 east, was easy, and beautiful. This has to be the prettiest time of year to drive out of the city. The hills are green, with yellow mustard and orange California Poppies. The spots that are not green are either a rusty red ochre or speckled granite. Pacheco Pass is an amazing place.

The turn to Dinosaur Point comes up fast. It is easy to miss, almost directly behind the sign. The road passes the entrance to Pacheco State Park, which was the old Rancho San Luis Gonzaga, back in the days of the California gold rush. The old stagecoach road can be seen down in a gully just past the entrance gate. The observing site is a large paved parking lot just above the boat launch at San Luis Reservoir. Literally hundreds of vehicles could park there.

The turnout was very good, a combination of lots of long time observing friends, with a good number of new attendees as well. We were all in for a treat.

The Zodiacal Light was huge. It was obvious well before dark. The seeing was never poor. It was excellent often during the night, with periods of slight softening. Saturn was easily winner of the beauty contest. Incredible, especially in a few Astrophysics refractors (5" and 6"), as well as a great home-made 10" Mak-Newtonian. In my 18" f/4.5 Dob, some of the real showstopper targets were at their best. M51 was showing spiral structure deep down into its core. The arms were etched at time. M94 too was showing tons of detail, big sweeping arms, an intense big nucleus, spiral structure in the outer core... the big globulars were at their best.

It was hard to go wrong. The only improvement I can imagine is to not have the seeing soften at all during the night. I'll put my order in now, for new moon June.

I didn't just look at big and bright stuff for the night. I was working the edges too. Probably the most challenging views of the night were Arp 204 and Hickson 66. Others were just plain interesting or fun, like NGC 5308, NGC 5322, NGC 5023 and NGC 5103. I finished the night sharing views of Copeland's Septet, with the entire group showing nicely.

This was truly a nice to enjoy being at the eyepiece, under a great sky, with your friends. More like this!

Even the drive home was easy. I was home by 3.

Here are my observing notes for the night. I didn't push it, enjoying the experience, looking through my friend's telescopes and sharing views through mine.

Arp 204 Cam GX 0.8'x0.3' 16.4 13 22 45 84 30 28 PGC46811
Arp 204 Cam GX 2.5'x0.5' 15.6 13 22 49 84 30 08 UGC 08454
18" 7mm - UGC 8454 is dim and elongated 3x1 E/W with no notable detail. Even brightness across. PGC 46811 lies to the W and is fleeting, coming in and out as a slight small amorphous brightening.

Arp 104 UMa GX 2.9'x1.6' 12.3 13 32 10 62 45 53 NGC 5218
18" 7mm elongated E/W and appears disrupted. Roundish, like it may be a spiral. Very dim star possibly embedded in E end. E end appears to hook N, W end appears to hook S. Even brightness throughout, no core visible.
Arp 104 UMa GX 2.4'x1.8' 13.6P 13 32 07 62 42 01 NGC 5216
18" 7mm about 7' S of NGC 5218. Appers round with bright core and stellar dim nucleus. Extended halo surround core but is qiuite dim.

Arp 238 UMa GX 0.9'x0.7' 14.4 13 15 29 62 07 27 UGC 08335
Arp 238 UMa GX 1.0'x0.6' 15.3 13 15 35 62 07 27 MCG+10-19-57
18" 7mm - small dim pair form this Arp. E/W to each other, with a pair of stars in identical orientation just to their N, forming an easy parallelogram. Eastern member seems brighter.

N5308 UMa GX 3.7'x0.6' 12.3B 13 47 00 60 58 23
18" 7mm - fairly bright and gorgeous spindle. Extremely bright stellar nucleus, maybe Seyfert galaxy. Elongated core around nucleus. Orientated SW/NE with hints of a dust lane along the 4'x0.5' size. Dust lane if there is on NW side of nucleus.

NGC5322 UMa GX 5.9'x3.8' 11.1B 13 49 47 60 11 26
18" 7mm - elongated E/W and about 2'x1'. Brighter core inside dimmer speckly halo, makes it look somewhat like a globular cluster. Nucleus is almost stellar.

N5204 UMa GX 5.0'x3.0' 11.7B 13 29 36 58 25 09
18" 7mm - elongated N/S about 3.5'x1.0'. Soft western edge, hard E edge. Even brightness across object, but hints of mottling and a slightly brighter core barely shows.

HGC066A UMa GX5 0.5'x0.4' 15.8B 13 38 38 57 18 44 MCG +10-19-104 PGC48226
18" 7mm - Hickson 66 is SSE of the nearby MCG 10-19-103, and appears clompy with a ENE/WSW orientation. Could be just one object elongated, but appears to be more than one.

Arp 239 UMa GX 0.7'x0.4' 15.0 13 41 43 55 40 23 NGC 5279
18" 7mm - very small with some possible NW/SE elongation. This Arp pair also has pairs UGC 8671 and MCG 9-22-94.
Arp 239 UMa GX 0.8'x0.6' 13.5 13 41 39 55 40 12 NGC 5278
18" 7mm - eongated E/W and fairly even brightness. Fairly bright.

NGC5195 CVn GX 5.8'x4.6' 10.5B 13 29 58 47 16 21
18" 7mm - bright nearly stellar core with a dark lane bisecting the galaxy NW/SE of the core, obscuring that side of the galaxy. W side of galaxy is round and bright but has a brighter bar NW/SE along the edge of the dark lane. Very interetsing object.

M51 CVn GX 10.3'x8.1' 9.0B 13 29 53 47 11 48 Arp 85
18" 7mm - incredible detail under very steady seeing. Main two arms are almost etched. Core has a bright stellar nucleus, with spiral structure within the core into the nucleus.

NGC4800 CVn GX 1.5'x1.1' 12.3B 12 54 37 46 31 50
18" 7mm - spiral with a dim pinpoint stellar core, 3'x2' elongated N/S. Bright core around the nucleus, with a large dimmer envelope around the core.

N5023 CVn GX 6.7'x0.7' 12.9B 13 12 11 44 02 20
18" 7mm - elongagted 7'x1.5' slightly W of N/S. Dim, pretty brightness across object, but hint of bisecting dust lane and several areas that appear to be brighter HII regions.

N5103 CVn GX 1.4'x0.9' 13.6P 13 20 30 43 05 02
18" 7mm - small, in beautiful setting at the end of a small chain of three other dim stars next to a bright star. Elongated NW/SE, in an oval. Appears to have a bright bar or spindle inside the halo. Very bright stellar core. Pretty object.

M63 CVn GX 13.7'x7.3' 9.3B 13 15 49 42 02 06
18" 7mm - very bright. Elongated 5x2 WWNW/EESE. Very bright pinpoint stellar nucleus surrounded by a large bright core about 4'x1.5'. Extensions off the core gradually dim, and have some hints of visible spiral
structure (dark lanes). Excellent example of a spiral galaxy.

M94 CVn GX 14.3'x12.1' 9.0B 12 50 53 41 07 10
18" 7mm - very bright, very large. Inner core is solidly bright and large, containing a pinpoint small nucleus. An outer core is distinct from the inner core, and appears somewhat mottled, possibly by tightly wound spiral arms. Two large sweeping spiral arms come out of the bright second core at the N and S and wrap around the galaxy, N to the W and around, S to the E and around. The bright outer core in moments of great seeing do show spiral structure and dark lanes. Galaxy outer core is elongated slightly NW/SE. What an objject!

Friday, April 17, 2009

Tight Split Night at Houge Park

I was at the SJAA's in-town public star party last night, at Houge Park. Early on, the skies were partly cloudy, but improved to "milky" as the night wore on. Transparency was clearly down, but little by little, the deep stuff began to show up.

I started out giving the public views of Saturn through my 10" f/5.7 CPT Dob. The seeing came and went, but when good, the views were outstanding. Lot of the public came by, there must have been over a dozen telescopes set up, and the fun people were having was obvious by the laughter and raucous buzz of voices.

I was very surprised to have very definite views of M65 and M66. Next door, another 10" had bright views of M81 and M82. The Sombrero (M104) showed up as an elongated streak, with one side clearly brighter than the other (the dust lane being the dark side). M13 and M3 were poor representation of their usual selves this night....

Someone was asking about double stars, and mentioned Porrima, which I had talked about in the beginning astronomy class. With a 7mm eyepiece in the scope, I was very surprised to see it cleanly split for long stretches of good seeing. Porrima is increasing in its separation, to
0.9" in 2010. A 6" AP running over twice the mag I had showed an amazing view, clean wide separation, nice round stars, and airy disks.

I moved on to Izar, which was interestingly more difficult that Porrima, due to the greater difference in magnitude of the components. Porrima is an almost equal double, while Izar is at magnitudes 2.3 and 5.

All in all, it was a fine night. I thought the tight split of Porrima stole the show.

The crowds thinned out after 11 P.M., and by midnight we were packing up to leave.

More observing tonight, with the gang, out of town.

Clear skies,


Saturday, April 4, 2009

Surprising Night at Houge Park

It turned out to be a much better night than expected. Weather forecasts called for wind increasing throughout the day, and reaching 25 mph during the night. It couldn't have calmer. Wispy clouds were appearing as I drove into Houge Park... but disappeared after sunset. There was a penetrating chill in the air at sunset as I set up my 10" CPT, but temps seemed to warm soon after. All in all, the night turned out to be a pleasant surprise... I stayed for the entire event.

With a full 1st quarter moon high in the sky, this was not a night for faint targets. A few people insisted on picking out galaxies, M81 and M82 were seen in telescopes as small at 4 inches. A 12.5" CPT gave the best view of M82, but still, not the night, thanks to Mr. Moonlight. I picked out M3, which broke into sprinkles of stars, but certainly wasn't its splashy self. Perhaps the best deep sky views were the big open clusters in Auriga (in the 12.5").

The real show of the night was put on by the moon and Saturn. Early on the seeing was okay, but not really tack sharp. I was cranking up the power on crater Eratosthenes, which was sliced in two by the terminator, enjoying the chain of craterlets sitting in the full sunlight, but wishing the steadiness could improve a bit. A neighbor with an 8" Orion Dob looked, and decided to get it in his scope. I looked at his view... it was fantastic. Detailed rilles and sharp edges on the craterlets. I was baffled, wondering how his smaller scope with mass produced optics (mine has pretty high end optics) could so clearly outperform my view! I went back to the 10" and looked again. It was the seeing! It transformed in a matter of minutes from acceptable to outstanding. The moon was giving up detail all over the place. This was totally unexpected, given the forecast for strong wind overnight.

That transformation kicked the star party into overdrive. Saturn now held up even in my most powerful eyepiece. The moon became a playground. Visitors were having fun, some so excited at the views words literally failed them - - - it was really, a surprising night at Houge Park.

It was also surprising to me, how much I have missed the public aspect of amateur astronomy. I used to be a regular at Houge, but over the past five years, seeking out darker sites further from home, my participation has been infrequent. This year has been a nice return. Maybe its time to bring sidewalk astronomy to downtown San Jose...

If you would like to participate at Houge Park, with or without a telescope, here is the events schedule for the San Jose Astronomical Association.

See you next time!