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. 

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.

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. 

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.  

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.

Sunspot Departs

Welcome Company

On April 16th I observed the Sun with my young friend, Luisa, a bright, curious international student from Brazil. Luisa has a deep interest in physics and astronomy. I feel so fortunate to be able to share common interests with Luisa. April 16th was a nearly perfect day with few clouds, light wind, low humidity, and temperatures in the mid to upper 60's.

We began using my troublesome new ZWO ASI 1600MM camera. From the start flashing horizontal lines were present on the laptop preview screen. I had hoped they would disappear when using a powered USB hub, but the powered hub by itself made no difference.

With Luisa's help, we were able to prove there is a faulty USB connection between the camera and laptop. She gently moved the USB plug at the camera while I looked at the preview screen. Sure enough, horizontal lines increased or decreased depending on how the plug was moved. There is a faulty connection right at the camera's USB plug on the camera body. The plug itself seems to be loose.

With Luisa holding the plug so that no lines were visible I captured the first image below showing sunspot 2738 approaching the Sun's western limb.

The picture above shows the kind of image the 1600 camera could produce if it were functioning properly.

With Luisa continuing to hold the USB plug, I took another image of the sunspot using a smaller region of interest.

Six days ago the umbra was split into two dark parts separated by a brighter dividing line. On this day the lower umbra was lighter than the upper portion.

Since the 1600 camera was malfunctioning, I decided to pack it up and use my trusty old ZWO ASI 174 camera instead. It has a smaller field of view, but at least it works as it should. The sunspot looked just as good with the older camera, but the reduced field of view is apparent if you compare the next image with the first image above.

As clouds increased I took three more images to blend together into the following three-panel mosaic.

Images from the old camera blended beautifully into a mosaic. In previous attempts, however, images from the new camera seemed to challenge and defeat all my mosaic building software.

I'm in the process of trying to return the 1600 camera, but don't know if this will be possible.

Rare Sunspot

Camera Struggles Continue

After many months with no significant sunspots a good sized spot finally appeared on April 10th. Two large prominences were also visible through an eyepiece. A four-hour window of clear skies along with comfortable temperatures in the mid 60's to low 70's made this a good day continue working with my ZWO ASI 1600 camera.

The first picture below, made with a 3X Barlow, shows solitary sunspot 2738, on an otherwise featureless disc. Only one prominence is dimly seen along the limb because exposure time and camera gain were not sufficient to properly capture dim prominences.

The camera malfunctioned from the very beginning of this observing session. Intermittent, thin, bright and dark horizontal lines appeared throughout the laptop preview screen. (A few of these defects show up along the limb at the very top of the previous image, but only if it is increased to full size.) It seemed like the camera couldn't download the chip contents completely without gaps in random locations. I tried pushing the USB plug in more firmly as well as using a different USB wire. I tried adjusting the USB traffic setting. Nothing eliminated the horizontal lines. Merely moving the Sun within the field of view caused horizontal lines to temporarily increase before settling into a less pervasive, but still existing effect. This problem did not happen during the previous three times I'd used the camera. Next time I'll try using a powered USB hub to see if it will eliminate the problem, but I'm beginning to think the camera has a hardware defect.

The sunspot itself had a bisected umbra more clearly visible in the next somewhat fuzzy cropped image.

A dramatic array of prominences were present around the limb as you can see in the next flawed image. Once again, I failed to capture prominences without also capturing unwanted, uneven background light. In this 2-panel mosaic the disc is overexposed. Horizontal streaks were also visible before I tediously removed some of them manually with Photoshop. (Click on the image for a larger view.)

Notice the imperfect blending of constituent panels at the bottom of the image.

After working with the 3X Barlow I switched to a 5X Barlow and successfully removed circular interference fringes by slightly loosening one screw on the tilt adjuster. This was one success in an otherwise disappointing session. Unfortunately, I couldn't continue working with the 5X Barlow because clouds moved in.

At this point I'm losing patience with this balky camera. If I can't find solutions to problems soon, I may try to return it and hope for a refund.