Tuesday, July 9, 2019

Currituck Lighthouse

Sights Near Corolla

While at the NC shore we decided to drive north along Highway 12 to explore areas we hadn't seen before. We found diminishing traffic, palatial shopping centers, large houses, and lovely Historic Corolla Park featuring the Currituck Lighthouse.
Lighthouse construction began in 1873 and was completed in 1875.
The lighthouse sits in a pretty shaded area featuring old restored buildings connected by brick walking paths. (Click on the following panorama to get a better idea of the layout.)
The lighthouse keepers' house, completed in 1876, (seen on the left in the panorama above), housed two families. It was restored and moved to its present position. A smaller house was moved to the location in 1920 and served as a home for a third keeper and his family. The smaller house, seen in the picture below, is now a museum shop filled with interesting items.
Park land extends far from the lighthouse itself. Here's a view looking back towards the lighthouse from the grounds of a "hunting lodge" built by wealthy landowners during the 1920's. A boathouse and lagoon appear in the foreground.
The view from near the boathouse itself reveals an attractive restored wooden bridge spanning the lagoon's exit into the neighboring sound.
The yellow "hunting lodge", seen in the next picture, was built by a wealthy couple, Edward Collings Wright Jr. and his wife, Marie Louise. Construction began in 1922 and was completed in 1925.
As we circled the house we saw enormous numbers of mosquitoes perched on the side just waiting for evening.
It was a pleasant surprise to find these attractions conveniently close to our vacation house.


Tuesday, July 2, 2019

Beach Fun

Southern Shores

We enjoyed a nice week at the North Carolina shore recently where our rental house was conveniently located a short distance from the beach. My daughter's happy family headed off to the ocean every day with their load of equipment.
Granddaughter Sophie is a joy to watch as she jumps over waves and frolics in the surf.
All week we had lucky weather and a calm ocean.
The smooth sea allowed paddle boarding near shore.
Annabelle sat in her pool with grandma.
Sometimes Annabelle even used her float in the ocean.
Sophie and Keegan launched a kite with boundless energy.
Sophie was fascinated by swarms of small crabs continually scurrying on the beach and popping in and out of the sand. She displayed crab parts on a beach chair so I could see the ones she collected.
One pleasant evening we strolled along the Duck Boardwalk where attractive scenes near sunset included: an isolated tree backlit by the setting Sun, seagulls on a wharf, a sunlit ripple pattern, and an osprey nest.
Some nice folks were kind enough to take this family portrait in front of the colorful sunset.
Back at the beach house we worked on the traditional jigsaw puzzle. Ellen and I became obsessed with completing the puzzle. We couldn't walk past without stopping to put a few pieces in place.
We chose a beautiful thousand-piece puzzle with lots of clearly defined lines and edges. (Last year's uncompleted puzzle, with lots of undifferentiated blue sky, was a nightmare.) This year we were happy to finish, although three pieces were missing in the end.
On our last morning Sophie wanted to see the Sun rise over the ocean, so the family went to the beach before dawn. Fortunately, the sky was clear down to the horizon, so sunrise was visible.
We've had two good years at this beach house and hope to return next year. 

Friday, June 7, 2019

Eyes on Eyepieces

Pleasant Evening

Modern cameras produce beautiful astronomical images. They reveal much more than the eye alone can see. But it's still wonderful to see celestial sights through a telescope with your own eyes. It's especially wonderful when you see things for the first time! We had a rare, cloud free night on June 3rd, and my bright young friend, Luisa, came to share some astronomical observing time with my Stellarvue 130mm refractor.
After overcoming initial telescope/mount pointing problems we settled down for more than two hours of fun. We attached eyepieces instead of cameras and decided to look at a sample of celestial wonders.

We saw six globular clusters: M13, M92, M12, M10, M5, and M4.

We saw six attractive double stars: Mizar, Albireo, Cor Caroli, Epsilon Lyrae, Acrab, and Algieba.

We saw the galaxy pair M81/M82, just capturing both in one field of view.

Open cluster M11 looked great, and the Ring Nebula M57 was spectacular.

The Swan Nebula, M17, showed some glowing gas, but only a hint of glow was apparent in the Lagoon Nebula, M8.

Louisa wanted to see how individual bright stars appeared through the telescope, so we looked at Vega, Spica, and Regulus. I also showed her the dim, but very red carbon star, T Lyrae.

By about 11:30 Jupiter had risen above the murky horizon. Luisa loved seeing Jovian moons arrayed beside Jupiter. I placed my phone on the eyepiece to grab the quick low quality picture of Jupiter shown below.
Jupiter is greatly overexposed, but you can see three moons beside the giant planet. Callisto is the moon on the bottom left. Europa is the moon closest to Jupiter on the right, and Ganymede is the remaining moon in the upper right. (The fourth Galilean moon, Io, was out of sight behind Jupiter.) The small dim object in line between Europa and Ganymede is actually a 9th magnitude background star called HD156182 which just happened to be aligned with the moons' orbital plane. Cloud bands on Jupiter were clearly visible to our eyes, but the phone camera wasn't smart enough to simultaneously capture both bright Jupiter and its relatively dimmer moons.

Saturn and its rings were near the horizon and showed a pleasing yellowish color in the eyepiece.

The telescope gave nice views, but we also saw some interesting naked eye events. The International Space Station passed over twice. Luisa saw a meteor streak across the sky. We also saw a tumbling satellite alternating in brightness as it traveled across constellations.

Eventually, some hazy clouds began appearing, and we were both getting tired after midnight. After the equipment was brought inside our exciting night was not quite finished. As I drove Luisa home at 1:00 am we passed hundreds of deer feeding along the roadsides, including one young buck who stood calmly in the middle of the highway blocking our way. I was astounded by the number of deer and glowing eyeballs reflecting our headlights! I drove well below the speed limit to avoid hitting them.

Luisa will soon return to Brazil. Farewell, Luisa! I'll miss you. 

Wednesday, May 29, 2019

Framed Rainbow

Rural Scene

While visiting my niece on May 25th in rural Orange, Virginia a late afternoon rainbow appeared attractively framed by backyard trees.
The background clouds are not very dark, so rainbow colors are not as dramatic as they could be.

A few moments before the previous picture was taken colors were slightly more intense.
The rainbow added extra beauty to the pleasant countryside visible from my niece's house.

Saturday, May 18, 2019

Sunspots, Old and New

Unexpected Activity

Thin early morning clouds cleared on May 7th leaving nearly clear skies, a light breeze, and temperature in the mid-60's. In a welcome change from the recent sunspot drought two spots and some prominences were on display this morning. The following 17-panel mosaic shows the unexpected features on the Sun's eastern hemisphere. (Click on the image for a larger, more detailed view.)
Sunspot 2740, on the right, is actually the same as old sunspot 2738. Sunspot 2738 remained intact long enough to travel across the Earth-facing solar disc a couple weeks ago, disappear around the western limb, travel across the solar far side, reappear on the eastern limb with a new number, and travel about one third across the solar disc again when this image was made on May 7th. A few days later it disintegrated leaving behind only its newer companion, sunspot 2741, seen near the eastern limb.

A nice array of prominences were scattered along the eastern limb as shown in the next 5-panel mosaic. Longer exposure time was used to capture relatively dim prominences. The overexposed solar disc has been blacked out, dim light levels enhanced, and yellow color added. It takes some work to make the prominences stand out above the background. I used both dark and flat field frames for this mosaic.
Both sunspots and a few prominences are captured in the next two single frame views. The first image was processed to bring out limb details. Notice the extended dark filament rising from the right side of sunspot 2740 in the first image. This was a transient eruption, as you can see by comparing the first image with the second image below taken 40 minutes before the first image.
It's difficult to preserve light and dark features in a sunspot umbra without decreasing the contrast of dark spicules. The next two images show this for sunspot 2740. The first image was processed to preserve umbra details. The second image was processed to show greater spicule contrast. (Click on the images to better see the umbral details.).
Solar minimum grinds on. Who knows when the Sun will display this number of features again. 

Saturday, May 11, 2019

Globular Clusters

Beautiful Evening

Evening, May 6th, a lovely night with no moon and temperature falling from the 70's to the 60's. I decided to try a ZWO 174 monochrome camera for night sky imaging. The camera was initially attached at prime focus on a Stellarvue 130mm refractor seen below waiting for darkness to fall.
The telescope is not permanently mounted, so its polar alignment is only approximate after each initial setup. Consequently, the mount alone will not track accurately enough for long exposure imaging. At present I have no way to make automatically guided images with a guiding camera. Although the mount tracks well enough for visual observing, stars slowly drift in the field of view as time goes on. This limits camera exposure times to values where star trails don't show up. I spent time trying different exposure times to see when star trails became visible. For example, at prime focus, I discovered exposure times less than 15 seconds were required to keep stars nearly round.

I then pointed the telescope at globular cluster M3 in the constellation Canes Venatici and stacked 40 individual 15-second exposures to make a single image equivalent to a 10-minute exposure. The next picture shows the result.
Notice the diagonal streaks above. These are caused by "hot pixels" in the camera chip. Actual stars don't trail in the image because software aligns all star images before adding them together in a stack. Unlike stars, however, hot pixels were not aligned, so the diagonal streaks show how stars would trail during a single equivalent 10-minute exposure if stars were not aligned before stacking. The hot pixels appear because I didn't take a dark frame for this image. A dark frame, or image obtained when no light falls on the camera chip, records the hot pixels and can remove them by subtraction. I manually removed the diagonal streaks in the next image, but a slight glow protruding on the right edge still remains.
As you can see above, the image scale is too small at prime focus. Stars look blocky instead of round. Star images look better with a 2X Barlow lens which produced the following image of globular custer M13 in the constellation Hercules. This is a stack of 40 individual 5-second exposures made with a gain setting of 350. I used a dark frame this time, so no diagonal hot pixels streaks are visible.
I don't know why I limited myself to 40 frames. In the future I will surely try for more. Next, I tried globular cluster M92 in the constellation Hercules. The following image is a stack of 40 individual 7-second exposures for a total exposure time of 280 seconds.
Finally, I had the best luck with globular cluster M5 in the constellation Serpens. There was a download malfunction while capturing images, so only 27 individual 7-second frames were stacked with gain setting at 320.
I moved the telescope to globular cluster M4 in Scorpius, but it was too near the horizon for good results. In the future I'll need larger stacks for longer equivalent exposure times. More magnification would also help. Although the grayscale images here are nowhere near as good as those produced by experienced dark sky imaging experts, I'm amazed at these first time results.  

Saturday, May 4, 2019

Beaver Dam & Birthday

Bike Ride With Sophie

A nice warm spring afternoon on April 25th was the perfect day to cash in a Christmas gift "coupon" from my granddaughter. This coupon treated me to a bike ride with Sophie, so off we went on the wonderful local bike trail. 
Our destination was a beaver dam near a wooden bridge along the trail. I have passed over this bridge many times, but never noticed the beaver pond until my daughter recently told me about it. Here Sophie stands on the east side of the bridge beside part of the dam.
The dam stretches the entire length of the bridge and beyond. Here's the view along the dam from its eastern edge.
Walking to the other end of the bridge gives the view looking from the west.
On the bridge's western end the dam begins to curve out to the right and continues in a semicircular arc seen in the next panoramic view.
Where are the industrious beavers who built the dam? We didn't see any. They are probably inactive during daylight. Their lodge is visible from the midpoint of the bridge.
This downed tree shows evidence of chewy beaver woodwork.
Apparently, some traps have been set in the area. Are these designed to control the beaver population, or to trap beaver predators? I don't know.
After our nice bike ride, Sophie and I joined her sister, Annabelle, and her Mom for an informal picnic celebration of Annabelle's 6th birthday. Annabelle really enjoyed listening to squeaky sounds on this swing with her Mom.
Sophie and Annabelle had a pleasant evening of fun after the picnic at the local playground.

People say I'm crazy doing what I'm doing
Well they give me all kinds of warnings to save me from ruin
When I say that I'm o.k. well they look at me kind of strange
Surely you're not happy now you no longer play the game

People say I'm lazy dreaming my life away
Well they give me all kinds of advice designed to enlighten me
When I tell them that I'm doing fine watching shadows on the wall
Don't you miss the big time boy you're no longer on the ball

I'm just sitting here watching the wheels go round and round
I really love to watch them roll
No longer riding on the merry-go-round
I just had to let it go

John Lennon