Milky Way and more Seestar photos

 In the late evening (10 pm MDT) at the end of August the Milky Way is standing tall in the southern sky.  Thursday night the sky was reasonably dark (sqml=21.45) and there was no breeze.  A few clouds lingered over the mountain ridges.

Sony A7iii + Laowa 15mm f/2 + Hoya Sparkle-6 filter.

Some faint red and green airglow was picked up by the camera in the northern sky.

Arcturus and the Big Dipper setting over Bristol Head.

The star at the top of the above image is Vega.  Arcturus and Vega have nearly the same brightness and are the fourth and fifth brightest stars in the sky, after Sirius, Canopus, and Alpha Centauri.

This was a good night to try out some more imaging with the Seestar S50 robotic telescope.  After leveling the tripod and calibrating the internal compass, it seemed to have no trouble finding objects selected from its internal database.  It was possible to sit comfortably indoors and use an iPad to watch images accumulate in real time.  The images in the following montage were all obtained with exposure lengths between 2 to 5 minutes.  Clockwise from upper left the objects are: M22 (globular cluster in Sagittarius), M27 (Dumbbell Nebula in Vulpecula), M20 (Trifid Nebula in Sagittarius), M13 (Great Hercules globular cluster), M16 (Eagle Nebula in Serpens), M8 (Lagoon Nebula in Sagittarius).

Finally, some stars!

 After the last full moon it has been almost non-stop cloudy and rainy.  Last night the sky was partially obscured by clouds, but also provided a brief look at the stars.  The open sky was moderately dark with a measured brightness of sqml=21.35 mpsas. These two images were obtained with an Olympus E-M1iii + Sigma 30mm f/1.4 lens + Hoya Softon filter.

Big Dipper descending over Bristol Head.

Sagittarius.  Galactic clouds partially obscured by Earthly clouds.

Blue Moon, active Sun, size comparison

 Lots of reports of auroras are showing up on the web.  Here is what the Sun looks like today:

White light. Astro-Tech AT102ED f/7 refractor + Lunt solar wedge + ND-0.6 filter.

Hydrogen-alpha light.  Lunt LS50THa.

There is (was) an interesting detached prominence near the western (right hand) limb.

The current full Moon is a so-called "Super Moon"  because it is near its closest approach to Earth.  This causes the apparent diameter to be slightly larger than average.  Here is an angular size comparison of the Moon and Sun taken with the same telescope (AT102ED):

Orange sun superimposed on a blue moon.

 The angular size difference of a "Super Moon" and an average full Moon is about the same as the difference between a 16" pizza and a 15" pizza viewed from 153 feet away.  Could you tell the difference?

Super Blue Sturgeon Moon

"Praise to the moon, bright queen of the skies,
Jewel of the black night, the light of our eyes,
Brighter than starlight, whiter than snow,
Look down on us in the darkness below."

John Renbourn, "Traveller's Prayer", 1998

 The full moon of August is known as the "Sturgeon Moon".  This year it occurs while the moon is near perigee (closest to earth), which makes it a so-called "Super Moon".  It is also the third full moon of the summer season, which will have four full moons this year.  That makes it a traditional "Blue Moon".

The angular size on 19 August is 33.4 arcmin.

Snowshoe Mtn ridgeline.  Canon FD 300mm f/4L.  9:00 pm MDT 18 Aug.

Canon FD 300mm f/4L

Seestar S50

Reflection. Canon FD 300mm f/4L

More images on Monday, 19 August:

Canon FD 300mm f/4L

Astro-Tech AT102ED f/7 refractor

Some nighttime Seestar images

 There was about one hour of mostly clear sky on Monday 12 Aug around 10:30 pm.  This provided an opportunity to try the Seestar S50 on something other than the Sun.

The Moon.

The Lagoon Nebula, M8.  2-min stack.

The globular cluster M22 in Sagittarius.  1-min stack.

These images are from post-processed FITS files and not the JPG versions saved on the iphone.  There is not a big difference, however.

A brief look at the sun with a new telescope: Seestar S50

 Saturday morning (10 Aug) as the sun rose over Snowshoe Mountain there was a brief window in time where the the clouds held back enough to provide a clear view to the east.  This provided an opportunity to test a brand new astrophotography telescope/camera, the ZWO Seestar S50.  

The Seestar is a robotic "smart" telescope (or, single-lens camera) that is controlled via an app on a phone or tablet.  You power on the device, connect via the app and use a menu to choose a target.  The device uses GPS and an internal compass to figure out where it is and where to point.  I was skeptical,  but with only a couple button presses it searched for and found the sun and locked on.  Impressive.

The Seestar uses a 50-mm diameter f/5 triplet objective.  In camera nomenclature this is a 250mm f/5 lens.  The imaging sensor is a Sony IMX462, with 2.9 µm pixels and a recording format of 1920 x 1080 pixels (5.57 x 3.13 mm).

first picture

2x digital zoom

Seestar S50 in action with solar filter installed

For comparison, here is an image taken with a much larger telescope, the Astro-Tech AT102ED f/7 refractor (fl = 714 mm).

E-M5iii. ISO 200, 1/5000 s, pushed two stops.

Large sunspot group currently visible.

AT102ED, after the clouds moved in.

Looking for the Northern Lights, finding airglow and a colorful sky

The new moon occurred on the morning of Sunday 04 Aug.  Milky Way viewing will get progressively harder as the moon waxes in the evening sky.  There are reports of auroras visible from some locations in Colorado.  In spite of substantial variable cloud cover, it seemed worth the effort to take some images Sunday evening to see what turned up .  The sky was noticeably brighter than average, with sqml=21.2 mpsas. 

All images taken with a Sony A7iii + FE 20mm f/1.8G lens, ISO 1600, 30 s.

Arcturus amid waves of airglow.  Sparkle-6x filter.

 The constellation Corona Borealis is in the center of the above image.  Astronomers world-wide are watching this constellation for the expected outburst of the recurrent nova T CrB.

The Milky Way with clouds and layers of airglow.  Sparkle-6x filter.

Airglow in the northern sky.  Sparkle-6x filter.

The Summer Triangle crossed with green and purple airglow.  Sparkle-6x filter.

The Milky Way and an active sun

There were some forecasts of auroral activity for the night of Monday 29 July, but nothing was visible to the unaided eye.  The sky was noticeably brighter, however, and a metered reading gave sqml=21.33 mpsas, about 45% brighter than the previous evening.  The camera revealed some strong green airglow.

The following images were obtained with a Sony A7iii camera and a 20mm FE f/1.8 G lens, ISO 1600, 30 s.

Milky Way over the southern end of Snowshoe Mountain. Hoya Softon filter.

 

Hoya Sparkle-6x filter

No filter.

These images have been color balanced to compensate for the strong green background, but it is still easy to see bands of green and purple at lower elevations. The third unfiltered image also illustrates how difficult it is to see constellation patterns without the use of a diffusion filter to enhance the brighter stars.

 In the northwest, bands of green and purple airglow were picked up by the camera:

Arcturus and the Big Dipper over the Bristol Head ridgeline. Softon filter.

Some images of the active sun were obtained the next morning:

The sun in Hydrogen-Alpha light (false color).

 

The sun in white light.

The Hydrogen-alpha image was obtained with a double-stacked Lunt LS50THa solar telescope and a ZWO ASI178mm camera.

Lunt LS50THa solar telescope.

 The white-light image was obtained with an Astro-Tech AT102ED refractor and a Lunt solar wedge.

AT102ED refractor set up for solar observing.