Patience and perseverance…

The forecast for the night of the 26th of September looked very promising, so I packed the car and set off for my Tebay Road site about at about 7.30 pm.  Full darkness was due at 9pm, so that would give me half an hour to drive and set up, plus a full hour for fine tuning the polar alignment.  It still needs practice.

Sadly the clouds had other ideas, and after a frustrating couple of hours trying to polar align through cloud gaps – in anticipation of clearing skies later – I decided to cut my losses and pack up shortly after 10pm.  Of course, that’s when the skies started to clear, in a tempting, optimistic kind of way, so I unpacked and started again from scratch.

From 11pm onwards, there followed about three hours of good conditions, occasionally excellent, in which I took about a hundred and twenty frames of various objects.  Afterwards, while the camera sat in the back of the car taking dark frames for calibration, I sat at the telescope eyepiece and manually calibrated the mount’s Periodic Error Correction system.

Good to be out under a clear dark sky!

First up, an attempt at Comet C/2014 E2 (Jacques), discovered in early March this year and now moving away from the Sun at about 32 kilometres per second (71,461 mph) at the time of writing.  Elevated 40º above the southern horizon, it makes a challenging target at Mag 10.0, given its distance of 175 million kilometres from Earth.  That part of the sky “moves” fastest, accentuating the slightest misalignment of the mount, so I restrict the exposure of each frame to just 45 seconds and push the ISO to 3200.  Here is the comet against half an hour of star movement:

C/2014 E2 (Jacques)  Nikon D90 on Altair Wave 115/805, 38x45 sec, ISO 3200

C/2014 E2 (Jacques)
Nikon D90 on Altair Wave 115/805, 38×45 sec, ISO 3200

Not my best comet photo to date, but it’s something.  Processing out the star movement:

Comet C/2014 E2 (Jacques) Nikon D90 on Altair Wave 115/805, 38 x 45 sec, ISO 3200

Comet C/2014 E2 (Jacques)
Nikon D90 on Altair Wave 115/805, 38 x 45 sec, ISO 3200

With the comet in the bag, I look to the zenith for promising targets.  NGC7789_WideThere have been a few to look forward to recently, and I am tempted by NGC 7789, a beautiful looking star cluster in Cassiopeia known as “Caroline’s Rose”.  It was discovered by William Herschel’s sister Caroline in 1783, and I have only seen it before in my wide-field photos of Cassiopeia.

Through the telescope, the camera’s field of view is only 1.68º x 1.12º and the cluster is indeed a beauty.  This shot is slightly cropped from full frame:

NGC 7789 "Caroline's Rose" Nikon D90 on Altair Wave 115/805, 20x45 sec, ISO 3200.

NGC 7789 “Caroline’s Rose”
Nikon D90 on Altair Wave 115/805, 20×45 sec, ISO 3200.

Between Cassiopeia and Perseus, the “double cluster” is next, NGC 869 and NGC 884:

Double Cluster in Perseus Nikon D90 on Altair Wave 115/805, 20x45sec, ISO 3200

Double Cluster in Perseus
Nikon D90 on Altair Wave 115/805, 20x45sec, ISO 3200

Then a very challenging edge-on spiral galaxy in Andromeda, NGC 891, showing angular size of only 11.7 x 1.6 arc minutes and Mag 9.9.  This galaxy is about 30 million light years away:

NGC 891 Nikon D90 on Altair Wave 115/805, 20x45sec, ISO3200

NGC 891
Nikon D90 on Altair Wave 115/805, 20x45sec, ISO3200

With the telescope in the region of Andromeda, it would be wrong not to take a peek, wouldn’t it?  Even with minimal processing, the Andromeda galaxy M31 makes a very big impression through the telescope and deserves a full session to itself on another night.

Andromeda Galaxy through the telescope Just 6 frames of 45 sec @ ISO 3200

Andromeda Galaxy through the telescope
Just 6 frames of 45 sec @ ISO 3200

Looking south west for darkness

Several locations around Kendal are dark enough for good astrophotography, but the one direction that causes problems is south west, where the lights of Morecambe Bay fill the horizon with their orange glow.

About an hour’s drive away is the West Cumbria coastline.  To the south of St. Bees it runs in a straight line from north west to south east, so it faces south west across the sea to the Isle of Man, Dublin or Anglesey (depending where you stand) with no urban lights to spoil the view.

From the car park at the end of the coast lane at Silecroft, the offshore wind farm sits exactly where the Milky Way hits the horizon, so I took the opportunity of clear skies last night to go and take a look. I had expected to find the wind farm illuminated only by starlight, but it was not to be!

Conditions were quite windy, so the mount was set up in the lee of the parked car.

First, the 50mm lens gives a viewing angle of 27º x 18º.

Start with 10 exposures of 10 seconds:

26 April 2014: The Milky Way from Silecroft. 50mm f/4 ISO 800, 100 sec. 10 frames of 10 sec.

26 April 2014: The Milky Way from Silecroft.
50mm f/4 ISO 800, 100 sec. 10 frames of 10 sec.

 

 

Increase exposure to 30 seconds, five frames:

 

26 April 2014: The Milky Way from Silecroft. 50mm f/4 ISO 800, 150 sec. 5 frames of 30 sec.

26 April 2014: The Milky Way from Silecroft.
50mm f/4 ISO 800, 150 sec. 5 frames of 30 sec.

 

 

The 24 mm lens widens the angle to 52º x 36º.

Seven frames of 60 seconds:

26 April 2014: The Milky Way from Silecroft. 24mm f/4 ISO 800, 7min.  7 frames of 60 sec.

26 April 2014: The Milky Way from Silecroft.
24mm f/4 ISO 800, 7min. 7 frames of 60 sec.

 

Moving up from the horizon, the summer triangle of Vega, Deneb and Altair extends almost to the zenith.

Three frames of two minutes per frame:

 

26 April 2014: The Summer Triangle from Silecroft. 24mm f/4 ISO 800, 6 min. 3 frames of 120 sec.

26 April 2014: The Summer Triangle from Silecroft.
24mm f/4 ISO 800, 6 min. 3 frames of 120 sec.

 

Why not stitch those together?

24mm Panorama

Further up the Milky Way, the 50mm lens again, for Cassiopeia looking down on Comet C/2014 E2 (Jacques).

Three frames at two minutes per frame:

26 April 2014: Cassiopeia and C/2014 E2 (Jacques) from Silecroft. 50mm f/4 ISO 800, 6 min. 3 frames of 120 sec.

26 April 2014: Cassiopeia and C/2014 E2 (Jacques) from Silecroft.
50mm f/4 ISO 800, 6 min. 3 frames of 120 sec.

 

Wide angle astrophotography is just as rewarding as going for long exposures at high magnification!

PANSTARRS through floodlights in the sky

Inspired by several astrophotographers around the world posting images of the amazing tail developing on PANSTARRS, I decided to have another go at this comet.  There is a minor road / very long layby running parallel to the A591 on the hill between Kendal and Staveley, with unimpeded views to the north.  I reckoned it would be almost as good as driving into the Kentmere valley.

En route, I dropped by Helsington Church again, to see how the planetary alignment was changing over the Langdales.  Jupiter, Venus and Mercury were now in a straight line and all clearly visible.  I met a delightful family who had come to look at the sunset after spending the day in Kendal, and we passed such an enjoyable half hour with my binoculars spotting planets that I forgot to take photos.

On to the layby, and quite easy to set up with Polaris visible in almost enough twilight to see the mount dials.  Hold on though, that northern sky is getting brighter, not darker!

18mm f/3.5, ISO 1600 1 sec.

18mm f/3.5, ISO 1600 1 sec.

Yes the noctilucent cloud season is under way.  I can’t make up my mind about these clouds that are only visible at night – is this astronomy or meteorology?  Yes, they are really pretty to look at, with amazing variation and complexity in their structure, but that’s Cassiopeia up there, and my dark sky location is ruined.

18mm f/3.5, ISO 1600 1 sec. Two High Pass filters: 40 pixels and 4 pixels.

18mm f/3.5, ISO 1600 1 sec.
Two High Pass filters: 40 pixels and 4 pixels.

Sharpened in Photoshop, the structure resembles waves on a beach.

Prompted by a comment on Noctilucent Clouds 2013, I have experimented with sharpening these images using two Photoshop techniques: Unsharp Mask and High Pass Filter.

NLC plain

50mm f/8, ISO 1600, 3 sec.

The unsharpened image.

NLC USM 200% 4P

50mm f/8, ISO 1600, 3 sec.
Unsharp mask 200%, 4 pixels.

Unsharp mask – Photoshop’s main choice of sharpening tool, but the effect can be seen across the whole image.

NLC HP40SL HP4HL

50mm f/8, ISO 1600, 3 sec.
High pass filter 1: 40 pixels, soft light blend.
High pass filter 2: 4 pixels, hard light blend.

High pass filter – this sharpens only regions of higher contrast ie edges, that benefit from sharpening but leaves the rest of the image untouched.  I picked up this tip from Nik Szymanek in a workshop at the International Astronomy Show in Leamington.  Nik was using it to enhance detail in galaxy images, but the principle applies just as well to noctilucent clouds.  I prefer this sharpening effect which doesn’t introduce the “sharpened feel” artefact to the whole canvas.

Anyway, eventually the light fades and I catch seven reasonable frames of PANSTARRS.

PANSTARRS passing Mag 4.3 Yildun and its Mag 5.8 partner "24 Ursa Minor". Yildun is the next star to Polaris in the tail of Ursa Minor. 200mm f/5.6, ISO 3200 7x3min.

PANSTARRS passing Mag 4.3 Yildun and its Mag 5.8 partner “24 Ursa Minor”.
200mm f/5.6, ISO 3200 7x3min.

Yildun is the next star to Polaris in the tail of Ursa Minor.

North is to the lower left of the shot, and the glow from the pesky noctilucent clouds can be seen in the comet’s tail – which is pointing pretty much towards the Sun.  I shouldn’t really moan about the cloud, as the Sun is only 13 degrees below the horizon so it’s not exactly dark anyway (from an astronomical point of view).

PANSTARRS success from Kentmere

Tuesday 30th April was sunny all day, the last patches of cloud drifting away to the north in late afternoon.  After my previous encounter with humidity and moonlight in Kentmere, it looked like a good opportunity to test this new dark site.

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This is how my setup looks.  Just me, a layby and the EQ3-2 equatorial mount.  At 9.30pm the Sun has already set, but I wanted to leave plenty of time in case it clouded over and I had to dash to another location.  It will be another couple of hours before the Sun is 18 degrees below the horizon, the offical end of astronomical twilight.

Elevation 25 degrees, Sun is 15.7 below horizon.

Elevation 25 degrees, Sun is 16.2 below horizon.

Elevation 25 degrees, Sun is 16.4 below horizon.

These unprocessed frames with the Sun only 15 degrees below the horizon show what a difference that makes to long exposures.

50mm f/2.8, ISO 800, 6 min. 2 X 240 sec. frames stacked in Photoshop.

50mm f/2.8, ISO 800, 8 min.
2 X 240 sec. frames stacked in Photoshop.

Two frames of 4 minutes each, stacked as layers in Photoshop.  PANSTARRS is in the centre, moving from Cassiopeia to Cephus.  The settings of ISO 800 and 240 seconds were inspired by Fred Espinak’s version, using pretty much the same kit.  I guess the difference in our results is an indication that, even on a good night in Kentmere, conditions in Arizona are better.  The thousands of stars in the bottom left corner (Cassiopeia is in the Milky Way) become so indistinct through our 80% humidity that they look like background glow, and any attempt to eliminate them damages the rest of the picture.  On the other hand, it could just be that Fred is much better at this than I am.

300mm f/5.6, ISO 3200, 12 min.
3 x 240 sec. frames stacked in Photoshop

With the 300mm lens, the optimum aperture is f/5.6 so I have wound the ISO up to 3200 to compensate.  Four minutes tracking with the 300mm lens is quite satisfying, with the stars showing no sign of trail.

PANSTARRS is passing close to two nebulae, Cederblad 214 and NGC 7822, between Cassiopeia and Cephus.  While neutralising the background, I notice that I have caught some nebulosity in Cederblad 214 – that’s the reddish glow to the right of PANSTARRS.

The comet itself still has two distinct tails.  The ion tail points away from the Sun (towards one o’clock in this photo) and the dust tail trails behind the comet (towards nine o’clock in this photo).

300mm f/5.6, ISO 3200, 5 min. Single frame of 300 sec.

300mm f/5.6, ISO 3200, 5 min.
Single frame of 300 sec.

Before packing up, I can’t resist an attempt at a five-minute frame.  The tracking seems to hold up well, which promises much for future sessions.