Our turn at last!

The recent weather patterns have tested the patience of many observers and astrophotographers in the UK, but on the night of 18 January, it was most definitely our turn for clear skies.  I drove to the church car park at Old Hutton at around half past five, to find three colleagues from the Eddington Astronomical Society already there!

There were three potential comet targets on my list that evening, resulting in varying levels of success and more lessons learned.

The handset of my AZ-EQ6 mount allows pre-programming of GOTO coordinates, so I had already loaded the comets’ coordinates in the warmth and comfort of home.  Once the mount was aligned, picking up the pre-programmed targets was very easy.  I also took the opportunity of the observing delay (caused by the slight cloud layer during the alignment process) to calibrate the mount’s adjustment knobs.

First up, low in the south west, Comet 15P/Finlay which is described in Sky Safari as magnitude +13, but is unexpectedly in “outburst” so significantly brighter.  I could see it clearly in the 24mm eyepiece at 33x magnification.  In the photo, its outburst form is very clear and really rather pretty.

Comet 15P/Finlay Nikon D90, Altair Wave 115/805 ISO 800, 6x3min.

Comet 15P/Finlay
Nikon D90, Altair Wave 115/805
ISO 800, 6x3min.

Finlay had to be the first target as it was only 15° above the horizon at dusk, and quickly setting.

Then on to Lovejoy, which was visible to the naked eye and also very strong through the telescope.  I had already attached the camera in place of the eyepiece on mine, so I got on with taking pictures.  This is Lovejoy on the same scale as Finlay:

Comet C/2014 Q2 (Lovejoy) Nikon D90 on Altair Wave 115/805 ISO 800, 13x3min.

Comet C/2014 Q2 (Lovejoy)
Nikon D90 on Altair Wave 115/805
ISO 800, 9x3min.

Switching to the 300mm telephoto catches more of the tail:

Comet C/2014 Q2 (Lovejoy) Nikon D90 and Nikkor 300mm ISO 800, 9x3min.

Comet C/2014 Q2 (Lovejoy)
Nikon D90 and Nikkor 300mm
ISO 800, 9x3min.

And finally a wide angle “context” shot through the trusty old 50mm manual lens (which came with my first Nikon, the F301, in about 1987).  The tail goes on for ever, past The Pleiades and the head of Taurus.

Comet C/2014 Q2 (Lovejoy) Nikon D90 and Nikkor 50mm ISO 800, 7x5min.

Comet C/2014 Q2 (Lovejoy)
Nikon D90 and Nikkor 50mm
ISO 800, 7x5min.

All in all, a very satisfying evening.

What about the third target?  More of that later…

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!

Nova Delphini 2013

The news of this star’s change to a nova about two weeks ago has highlighted the frustrations of Cumbria-based amateur astrophotography. Work commitments, late evening sunsets, early evening moonrises, waxing gibbous / full / waning gibbous moon phases and Cumbria’s generally cloudy night time conditions have combined on this occasion to make this discovery more “internet” than “actual” for me.

Nova1

This crop from a wide angle shot taken from Shap on a “clear” night illustrates the vagaries of Cumbrian weather forecasting. I stayed for another hour after this, waiting for the clouds to pass by, but they just got thicker and thicker. Nova Delphini 2013 is there, in the top left of the frame, but it was a hurried single-frame capture.

Last night, 25th August, promised clear skies and a sunset about 90 minutes before moonrise. Off to Helsington Church, set up to catch a view to the south in the gap between sunset in the north west and moonrise in the east. As the light faded, I was joined by a family who had come to look for shooting stars, so we swapped tales of stargazing as the darkness fell. I think at least one of them has decided to come and try the Eddington Astronomical Society meetings (if you don’t already know, they are on the first Monday of the month, 7-9pm at Kendal Museum, all welcome)!

50mm 4x30 sec  5.6 1600 paths8

50mm f/5.6, ISO 1600 2 min.
4 frames of 30 sec, stacked in DSS.

Once the background light had faded, conditions were pretty good. The air felt humid, but the sky was clear. Clockwise from the bottom, Altair, Delphinus the Dolphin, “the wonky H”, Nova Delphini 2013, Sagitta the Arrow, Brocchi’s Cluster – the “Coathanger” asterism.

50mm f/5.6, ISO 1600 2 min.
4 frames of 30 sec, stacked in DSS.

Again, without the lines. Photoshop has been used to take out some of the background glow. The sky never became fully dark as the Moon rose when the Sun was only about 12 degrees below the north-western horizon.

300mm f/5.6, ISO 1600 6 min.
6 frames of 60 sec, stacked in DSS.

The contrast and the magnification are increased with a 300mm lens.

300mm f/5.6, ISO 1600 6 min.
6 frames of 60 sec, stacked in DSS.

So I caught Nova Delphini 2013 at last, although it is now below its peak magnitude of about 4. Invisible to the naked eye last night (probably due to the never-quite-dark sky), in binoculars I estimated it at about Mag 5.5 – 6.0.  The “wonky H” asterism is made up of stars that are all below Mag 6.

PANSTARRS one last time?

This is an awkward time of year for astrophotography. It only gets really dark after the end of “astronomical twilight”, when the Sun dips 18 degrees below the horizon. That didn’t happen until quarter past midnight last night, and by 2am it was back above that 18 degree line. The longest day / shortest night is still six weeks away, so for the next twelve weeks the night sky will be at least as testing as it is now.

These photos were taken in the hour around 1am last night, from the long layby set back from the A591 east of Staveley.

First, the constellation Cepheus:

PANSTARRS approaching Cepheus 50mm f/5.6, ISO 800, 15 min. Single frame of 15 minutes.

PANSTARRS approaching Cepheus
50mm f/5.6, ISO 800, 15 min.
Single frame of 15 minutes.

The 50mm lens gives a 27×18-degree field of view on the D90, so just enough space to accommodate the whole of Cepheus as PANSTARRS (mag 7.2) approaches from Casseopeia.

At ISO 800 all the numbered stars in Cepheus are fully illuminated on the screen, including Erakis (mag 4.1), the “Garnet Star” on the right.

On to PANSTARRS with the 300mm lens:

PANSTARRS approaching Cepheus 300mm f/5.6, ISO 800, 8 min. 2x4 min. frames stacked in Photoshop.

PANSTARRS approaching Cepheus
300mm f/5.6, ISO 800, 8 min.
2×4 min. frames stacked in Photoshop.

PANSTARRS approaching Cepheus 300mm f/5.6, ISO 800, 8 min. Single 8-minute frame.

PANSTARRS approaching Cepheus
300mm f/5.6, ISO 800, 8 min.
Single 8-minute frame.

Two questions are answered here. First, does a stack of two 4-minute frames deliver more than a single 8-minute frame (all other settings unchanged) or is it the other way round? Decide for yourself, but I think there’s more refinement in the layered 4-minute frames and more punch in the single 8-minute frame.

Second, can the EQ3-2 mount track accurately for 8 minutes loaded with the D90 and a 300mm lens? Looks good to me.

At 2am it’s getting light in the east (!!) so time to pack up. I’ve had great fun photographing PANSTARRS over the last few weeks and learned many lessons along the way, but this is probably the last session, given the combination of short, late nights and uncertain Cumbrian weather.

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.

_CSC0003

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.

PANSTARRS in Casseopeia

First attempt, a fairly optimistic shot over the garden fence on 19 April.

Casseopeia with PANSTARRS

18-200mm @ 65mm f/5.6, ISO 1600, 6 min
12 x 30 sec frames stacked in DSS

The clear sky had tempted me to set up the kit, but the urban glow catching the moisture in the atmosphere defeated any serious attempt to produce a reasonable photo. I thought that stacking several frames would help edit out the glow, but it doesn’t work that way.

Out to a new site on 20 April, in a layby part way up the Kentmere Valley.

C&P4x30

50mm f/2.8, ISO 800, 2 min
4 x 30 sec frames stacked in Photoshop

Skies were forecast to clear for an hour or so around midnight, but the waxing gibbous moon spread light throughout the sky. There were a few wisps of low cloud on the northern horizon. These 4 frames were stacked as layers in Photoshop.

My intention was to assess the suitability of the site for views to the north. Having escaped the street lights of Kendal, the next town north from Kentmere Valley is Penrith, some 19 miles away over mostly uninhabited countryside. It was pleasing to see there was almost no discernible urban glow in the northern sky.

C&P4x2

50mm f/4, ISO 800, 8 min
4 x 2 min frames stacked in Photoshop

Finally, four reasonable frames of 2 min each, relatively cloud free. Given that I was able to write notes by the moonlight, and the humidity was high enough for cloud inversion to begin settling in the valley (see bottom right corner of the photo), this is a pleasing result. Certainly I will visit this site again around the New Moon in about a fortnight. Cloud permitting…