Category Archives: Observing Log

Posts describing an observing session or astrophotography session.

Images of Comet c/2104 Q2 (Lovejoy) – 2015-01-19

Using a Stellavue 80mm APO (with 0.8x reducer) and a Canon T2i, i took some images of comet Lovejoy. The main imaging run was 30 x 2 min exposures at ISO1600. The comet is bright enough that the core is blown at this exposure. So i also took a series of shorter exposure sets at 60s, 30s and 15s. Unfortunately, i could not create a high dynamic range image (HDR) with the short exposures – either automatically with the tools i have nor manually.

I was guiding on a star and not accounting for the relative motion of the comet. At 2 min expsoures, it’s manageable as the comet is not moving so fast that it would show any noticeable signs of being stretched in each frame. However, after an hour it had moved considerably in the FoV, so each frame had to be realigned to the comet’s new location. The 30 aligned frames were then stacked with a rejection filter. This provided the best image of the comet at the expense of dimming the background stars. (A simple averaging would keep each star and the result would be a line of stars giving the impression the comet was racing past them – which it is.)

Comet c2104 Q2 Lovejoy 2015-01-19 comet aligned

Comet c2104 Q2 Lovejoy 2015-01-19 comet aligned

The part of the tail visible in the image above is 2.2deg wide. This works out to 3.3Mkm in actual length and that’s not all the tail. The distance from earth to the comet was about 85 Mkm when the image was taken.

To get an image with the background stars, i reprocessed just 5 of the images and aligned on the stars. Even with a 10min lapsed time, the comet is still not stretched too much in the final image.

Comet c2104 Q2 Lovejoy 2015-01-19 star aligned

Comet c2104 Q2 Lovejoy 2015-01-19 star aligned

Comet c/2104 Q2 (Lovejoy) – 2015-01-15

A bright comet is moving through the solar system and in January is just getting bright enough to be visible unaided.

I managed to see Lovejoy unaided from my location just south of Carp at 10pm on January 15th. The light pollution map shows my location as orange, but it’s probably a little better than that looking south west where the comet was.

The comet was just visible with averted vision and occasionally while looking directly at it. With binoculars it was of course obvious, but no tail was detectable. With my 173mm, f/5.7 Dob, the core was very distinct within the larger halo. Still no tail.

For brightness comparison, Botein, Epsilon and Zeta Aries were also just visible – mag 4.34, 4.69 and 4.84. However 63 and 47 Aries – mag 5.09 and 5.78 – were not.

North America and Pelican Nebula – 2014-10-24

The region around the brightest star Deneb in the constellation Cygnus is occupied by a giant cloud of ionized molecular hydrogen (H II or H2) which is categorized as an “emission nebula”. Three degrees towards the north are two nebula named the “North America Nebula” (NGC 7000) and the “Pelican Nebula” (IC 5070).

NGC7000-IC5070 - North America and Pelican Nebulae - 2014-10-24 v1

NGC7000-IC5070 – North America and Pelican Nebulae – 2014-10-24 v1


The image spans 3.2 x 3.0 degrees which translates to an object size of 96 x 89 ly

The interesting  “North America” shape is caused by interstellar dust blocking some of the light from the nebula. Therefore the stars in the “”Gulf of Mexico” are in front of the dust and closer to us than the actual nebula. The peninsula is referred to as the “Cygnus Wall” and the bright filaments along the wall are regions of intense active star formation.

IC5070 - Pelican Nebula 2014-10-24 v3 high contrast

IC5070 – Pelican Nebula 2014-10-24 v3 high contrast


The Pelican nebula is supposed to look like a pelican taking flight. With the low contrast in my image it’s hard to make out. The pelican is facing towards us and to the left. The top of it’s head is the peak above the bright filament in the upper centre and it’s full beak is pointing down to the left and formed by the cloud along the upper left edge of the nebula. The vertical filament itself outlines the back of the pelican’s neck. The right part of the nebula is then the bird’s right wing on the downward part of a stroke. The left wing would be behind the pelican’s beak.

The pelican shows up better in the high contrast version of just IC 5070 (reprocessed from the same image above).

Generally emission nebula are difficult to see. Although quite large and bright in H-alpha, it is not possible to see this object unaided. The ionized hydrogen glows strongly deep red from the primary Blamer series Hα (hydrogen alpha) at 656nm. Unfortunately our night time vision (scotopic vision) tops out at 620nm, so we cannot see the Hα faint red glow. (Our day time vision – photopic vision – can see deep reds up to about 750nm when they are bright daylight intensities.) But the nebula also glows in other wavelengths so it is possible to see it.

There are some reports that the formation can be seen with binoculars or a small telescope using a UHC filter. I suspect this has to be done under dark skies and ideal conditions. I have never been able to make it out from my semi-rural location.

North America Nebula
– Magnitude: 4.0
– Angular Size: 120 x 100 arc-min
– Distance: 1,600 ly

Pelican Nebula
– Magnitude: 8.0
– Angular Size: 60 x 50 arm-min
– Distance: 1,800 ly

This is a two pane mosaic. The left part of the NA Nebula is from a data set acquired 2010-10-09 using a TV Pronto and Canon XS. The right side of the image, including a good portion of the NA nebula and all of the Pelican Nebula was acquired 2014-10-24 with a Stellarvue 80mm APO and a Canon T2i. The Pronto and SV80 have the same FL of 380mm, but the cameras are different so the image scales of the two sub-frames are different. The Pronto image was up-scaled to match the image scale of the Canon T2i and then aligned and merged to form the composite image.

Super Moon 2014-09-09

A “super moon” occurs when the moon is full (or new) and is also at it’s closest approach to the Earth (perigee). When this happens, the full moon appears bigger and brighter compared to other full moons. The difference in size is only 16% compared to the smallest full moon – a full moon at apogee or micro moon. So it’s actually very hard to notice the larger apparent size unless you see the super moon presented beside the micro moon.

While i don’t like the term “Super Moon” the media has latched onto it, so that’s what i’ve call this post. The correct term according to wikipedia is “perigee-syzygy of the Earth-Moon-Sun”. Ok, doesn’t roll off the tongue very well. But a simpler term is “perigee moon”. Perigee meaning the point where the moon is closest to earth during it’s monthly orbit. Both a full moon and new moon at perigee are considered a “super moon”, but the media doesn’t seem to care about the new moon event. (At new moon you can’t actually see the moon since it’s directly in line with the sun.)

When a full moon or new moon occurs, the sun, earth and moon are aligned so their mutual gravitational forces are also aligned and the combined affect on the earth’s oceans is at it’s greatest. At perigee the moon’s gravitational pull on the earth is also at a maximum. So the combined affect of the sun and the super moon can have a mild affect on tides. And if a perigee moon occurs in spring when tides are already at their highest, the additional affects of a perigee moon can be noticeable.

It’s always reported in the media that the perigee full moon makes the tides higher. But it occurs to me that at full moon, the moon and sun are on opposite sides of the earth. So it would seem their gravitational pull on the oceans should cancel out and the tides would therefore be smaller. I don’t know if this is the case however.

Usually there are 2, and occasionally just one perigee moon in a calendar year. The coincidence of full moon with perigee occurs every 13.94 months. The new moons before and after the full moon can also be at perigee so it’s possible to have 3 super moons in one calendar year. This occurred in 2014 with super moons on July 12th, August 10th, and Sept. 9th.

On September 8th, i took a photograph of the almost full moon just around sunset – or moon rise.

Super Moon 2014-09-07

Super Moon 2014-09-07

The next day was actually the super moon event and i took this photo:

Moon - Super Moon 2014-09-08 v2

Moon – Super Moon 2014-09-08 v2

M81-M82 – Bodes Nebula – 2014-04-24

The data for this image was collected in April but i didn’t get around to processing the image until last week. I was working through a new image processing workflow based on PixInsight. It didn’t really take 6 months to develop the process, it just took that long for me to get around to it.

Bode’s Nebula is in the constellation Ursa Major, and therefore towards the north. Until last year when the trees to the north came down, this target was out of view.

The data was aquired over three nights. However, there were a lot of technical problems (and operator error) so only 2 of the three nights produced usable results. And then only a partial set of the data from the other two nights was acceptable. Still, there is 5hrs of integration time which is enough to produce a reasonable image.

M81 (NGC 3031) Bode’s Galaxy
Face-on spiral galaxy in Ursa Major
Dimensions: 26.9 x 14.1 arc-min
Magnitude: 6.94
Distance: 11.8 mLy

M82 (NGC 3034) Cigar Galaxy
Edge-on spiral galaxy in Ursa Major
Dimensions: 11.2 x 4.3 arc-min
Magnitude: 8.41
Distance: 11.4-12.4 mLy

M81-M82 - Bodes Nebula - 2014-04-24

M81-M82 – Bodes Nebula – 2014-04-24

The bright star in the upper middle of M82 is a supernova SN 2014J which appeared 2014-01-21 at 19.20 UT. A close crop with an annotated view shows the location of the super nova.

M82 -SN 2014J - 2014-04-24

M82 -SN 2014J – 2014-04-24

NGC6946 – Fireworks Galaxy 2014-09-26 v2

The Fireworks Galaxy is technically in the constellation Cygnus, but it is quite a bit to the north. Until the trees were removed last year that obsecured the northern sky, circum polar objects were out of view.

NGC 6946 (Arp 29, Caldwell 12) – The Fireworks Galaxy.
Dimensions: 11.5 x 9.8 arcmin
Magnitude: 9.6
Distance: 22.5Mly (+/- 8Mly)

NGC 6946 - Fireworks Galaxy - 2014-09-26 v2

NGC 6946 – Fireworks Galaxy – 2014-09-26 v2

The data for the image was collected over three nights from Oct 24 to the 26th. Amazingly there were 3 clear night in a row all with good seeing. The total integration time is 15hrs which is a bit of a record for me.

Not Much Summer Astronomy Happening – 2014-07-09

The late sunset for a few weeks before and after the summer solstice means that any deep sky observing can’t even start ’till quite late. Therefore i tend to abandon any plans for serious observing in the late spring and summer. The early sunrises also reduce the available dark sky time, so photography is a bust. That, and using a DSLR means that the camera sensor is hot – like 25c – so long exposures are quite noisy. In Ottawa, astronomical twilight is as late as 11:30 with dawn around 2:30. Even in July the skies don’t really get dark until 10:30.

I have therefore taken to quite casual observing. Mostly this means taking in the few star and planets visible when i take the dog for a walk around 9pm. I might get out the binoculars but not usually.

In June, i did manage to see Saturn, Mars, Jupiter and Mercury in the evening sky – all at the same time. I was actually lucky enough to see this lineup on two or three nights.

Just this month, i saw the conjunction of Mars with the 2 quarter moon. I think they were less than 1 degree apart.

The summer constellations are coming into view – Scorpios and Sagittarius. The latter a little later in the evening right now. The centre of the milky way is just a little right of Sagittarius and therefore is the brightest and most prominent section. By late August and September the milky way will be at it’s best in the evening.

I plan to start some astrophotography projects perhaps in late August when the nights are cooler and the skies are darker at a more reasonable time.

Trapezium Project – 2014-01-22

Imaging the trapezium – the multiple star cluster at the centre of the Orion Nebula (M42).

Equipment:

Scope: EdgeHD 11 (focal length 2800mm, f/10)
– astro-tech diagonal (too cold to refocus for straight through config)

Camera: Canon T2i modified with astrodon UV/IR filter
– Pixel pitch advertised as 4.30 um
– Width: 22.30 x 14.90mm
– Active Pixels: 5184 x 3456
– Astro SW though uses 5202 x 3465 pixels.

Mount: CGE Pro
– unguided, no PEC, PA hasn’t been done in awhile

I calculate the resolution of this optical train as 0.32 arc-sec per pixel.

However, a platesolve using Platesolve2 (by Dave Rowe) and the UCAC3PS catalog results in a resolution of 0.266 arc-sec per pixel.

From a run last year with the HD11, 5x powermate and a chameleon webcam i got this result:

Trapezium with 6 members resolved

Trapezium with 6 members resolved – 2013-04-01

 

The table below are the stacked versions of several different exposures.
– The picture is a tight crop of just the trapezium with a moderate stretch. Something akin to what the camera does for a non-linear jpg.
– The platesolve is the result of the platesolve2 on the fits file.
– the fits file is the full frame of a the stack of the calibrated and aligned lights for that exposure. The data is linear 16bit RGB.

To download a .fits files, right click and select “save as”. (Clicking on the link just opens up the .fit file as a text file, which isn’t any good at all.)

Note that all fits files are align to the same master. So its possible to combine the individual exposures into an HDR.

trap_1x4s_iso400.fit
integration: 4 * 1/4sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_1s_iso400.fit
integration: 2 * 1sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_2s_iso400.fit
integration: 4 * 2sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_3.2s_iso400.fit
integration: 5 * 3.2sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_5s_iso400.fit
integration: 5 * 5sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_10s_iso400.fit
integration: 6 * 10sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_30s_iso400.fit
integration: 5 * 30sec at ISO400
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_30s_iso800.fit
integration: 7 * 30sec at ISO800
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB
trap_30s_iso1600.fit
integration: 6 * 30sec at ISO1600
pixels: 5202 x 3465
format: RGB, 16bit unsigned int
Download size: 105MB

Observing Report – 2014-01-14

After 8 weeks of almost no astronomy, i finally opened up the dome. In truth, i did take out the 3″ refractor a couple of times for a quick peek at things from the front porch. But for the last 2 months it’s either been cloudy or there was a full moon when clear so not worth getting out the big scope. There were 2 decent clear nights, but social engagements precluded spending an evening in the observatory.

Pyroclastic formation south east of Mare Vaporum

Pyroclastic formation south east of Mare Vaporum

On Jan 14th there was also an almost full moon. But i had a specific objective for looking at the moon when full. When doing a little research for my image of the pyroclastic formation near Mare Varopum, i found a reference that stated the dark pyroclastic formation could even be seen at full moon.

The forecast was for clear skies in the late evening with moderate to poor seeing. The skies were clear and quite transparent and the seeing on occasions was actually 4/5 – but only for a few seconds at a time. Mostly it was the predicted poor 2/5.

Using the HD11 and 24mm Hyperion (mag 116x and 35′ real FoV) i first checked out the double in Rigel. At first the glare from Rigel obscured the companion. But when the seeing stabilized, it was easy to see.

Betelgeuse was a beautiful orange. I half expected it to go supernova while observing it. It’s reported to be quite unstable and ready to explode sometime between now and the next million years.

Just for fun, i slewed to Alnitak – the left most star in Orion’s belt. And then down a half a degree to where the horse head nebula is. Of course i could not see it as it’s really an HA object and only visible in HA capable cameras.

trapezium 6 starsThe next target was the Trapezium in Orion’s sword. It’s at the centre of the Orion Nebula (M42). The centre of the nebula is visible in an EP as a distinct grey patch with well defined edges. Averted vision affords some structure to the otherwise smooth “cloud”. The 4 stars that form the bright trapezium – mag 4.96 to 7.46 – were of course obvious as the separations vary from 9″ to 19″. After a few minutes of observing, i also detected a 5th member – E – which is mag 10.3 and positioned between A and B. The 6th member F is mag 10.2 and should have been visible, but i did not see it. To my credit, i did not know where E and F were located, so the observation is by merit alone.

The image below captures what it’s like to try to see the faint E and F members. The tear drop shapes are due to atmospheric dispersion as the image was taken when Orion was quite low in the sky. (Note that this image is flipped relative to the graphic above.)

Trapezium with 6 members resolved

Trapezium with 6 members resolved – 2013-04-01

I took a quick look a Jupiter. The seeing wasn’t very good at the time so i could not make out any details expect for the major bands. There were 3 moons visible at the time of observation at about 9:30. These were Io, Europa and Callisto. Had i waited just a few more minutes, i would have seen Ganymede emerge from behind Jupiter.

The last target was the full moon. Even with a 10% neutral density “moon” filter, it is blindingly bright. After a few minutes to orient myself and get used to the flipped horizontal view with an SCT and diagonal, i was viewing Mare Varporum. The ridges on the formation of interest were just visible as bright jagged lines. I could not detect any darkening in the region even though at other lunations, this region is distinctly reddish in colour.

Observing Report – Mare Vaporum – 2013-12-12

I am pretty sure i was observing on the 12th, although it may have been Dec 11. It’s  important because the phase of the moon plays an important role in what can be observed on the lunar surface.  I do know it was clear and pretty $#^&* cold with temperatures below -20c at 10pm.

Pyroclastic formation south east of Mare Vaporum

Pyroclastic formation south east of Mare Vaporum

I had found statements that the dark pyroclastic formation to the south east of Mare Vaporum was observable even at a full moon. I had just completed my image of that area taken with a lunation of 7days, so was keen to test that statement. I grabbed the 70mm Telvue Pronto, which was already on the camera tripod, and observed from the front porch at 10pm to see if i could find the “dark spot” below Mare Vaporum.

Using the 70mm scope and a 5mm Hyperion yields a magnification of 96x and a real FoV of 42′. So the whole moon didn’t quite fill the field of view but provided enough magnification that i was hopeful of seeing the details i was after. The seeing was actually quite poor despite the seemingly very transparent skies. I was also observing at about 10pm so the moon was high in the sky and due south which should have been ideal. I think the cold winter air gives the impression of being clear, but the seeing (stability) is generally poor in these conditions.

Mare Vaporum was easy to spot. As well 4 dark “spots” to the south east were clearly visible. The one furthest east is the large crater Julius Caesar. Just west of that is the crater Boscovish. Then there are two dark spots that together with Boscovish form a line going south west. I presume the two additional spots are the craters Hyginus Z and Hyginus S.

As for the pyroclastic formation, i think with a little stretch of the imagination i did see it. But the seeing was poor and the magnification and resolution of the 70m Pronto was probably marginal for that task. As well, the camera tripod was affected by the stiff breeze making it hard to get a stable fix on the object of interest.

I will have to try again with the HD11 on the motorized CGE Pro to be able to definitively say that the dark formation is visible past the 1st quarter moon.