BACKYARD ASTRONOMY FROM PALMERSTON NORTH

NEW ZEALAND

A city-centre site is not ideal for astrophotography, but the photographs on this page were taken from near the middle of Palmerston North.
They show objects that are visible to the unaided eye. Some were taken with a DSLR camera through a telescope and are time exposures, or produced from stacking hundreds of single shots from a webcam, so show more detail.

Send email inquiries about material on this page to astronomy@meldrum.nz

FINDING THE SOUTH CELESTIAL POLE

To set up the computerised telescopes they need to be pointing at the south celestial pole (the place in the sky that the Earth's axis points towards). All the stars appear to move around that spot as the Earth turns. It is about halfway between the Southern Cross and the bright star Achernar. The two hour time-lapse movie below was taken from behind the PNBHS cricket pavilion, towards the south and the city lights. The labelled photograph is the first of the time-lapse series.

SAGITTARIUS ON 21 JULY 2017

Last winter we concentrated on observing the numerous deep sky objects close to Scorpius (see the photograph below).

 

This year we have moved to the neighbouring constellation, Sagittarius. Most folk recognise it because of the teapot shape. It follows Scorpius, rising just a little later in the eastern sky. There was no moon on 21 July this year, so this 20 second exposure shows the steam (Milky Way) coming out of the spout, without moonlight pollution hiding it.

 

The Corona Australis is to the south of Sagittarius and not visible north of 53o so cannot be seen from the United Kingdom, but can from southern Europe and the southern United States. We are far enough south for it to reach high into our winter night sky.

SCORPIUS ON 12 JULY 2016

Scorpius is the most well recognised winter constellation. This year both Mars and Saturn are nearby.

This photo was taken low in the sky (towards the east) just after it became dark , but the moonlight and city lights cause poor contrast. Labels have been added to point out the most interesting areas. Antares means "rival of Mars", yet Mars is so close to us at present that it clearly outshines the star. They are both red in colour.

The centre of the Milky Way passes close to the tail of the scorpion causing the cloudy appearance. Use binoculars or a small telescope to get a better view of the star clusters and nebulae.

SATURN

This photograph of Saturn, showing the Cassini division, was also taken on 12 July 2016. It was made by stacking the best frames from a minute-long movie taken through a telescope. That movie of the planet is shown on the right.

The shot of Saturn on the left was taken on 20 April 2012. The increasing tilt with time has brought the rings into a position where we can see some detail. The pale outer ring is clear, and the Cassini division between it and the inner ring is just visible.

In September 2009 we passed through the plane of the rings so they looked like a straight line through the planet. The black and white shot on the right was taken on 13 July 2010. The maximum tilt will occur during 2017, so our view of Saturn is at its best now.

MARS

Although the most Earth-like of all the planets it is rare to be able to make out much detail on Mars. This was probably shot during a dust storm. Taken from the Earth's southern hemisphere the image is upside down. The pale area at the top is the southern polar cap of Mars, probably consisting of dry ice. The dark area just below is Syrtis Major (it is triangular and looks like a map of India). Is actually dark balsamic rock.

These two photographs were taken in October 2015 at the last observation evening of the year. The security lights on the buildings made it difficult to see deep sky objects.

The right hand shot is towards the west and Saturn was lower in the sky each night, by November it was too close to the sun to be seen. It is the brightest light in the sky, close to the top left corner. The telescope is being moved to view it.

VENUS IN JULY 2015

Apart from the moon, Venus is the brightest object in the night sky. Yet it is only a crescent. This photo was taken at 6pm on 13 July through a 9cm refracting telescope, using the little Neximage camera.

On 6 June Venus reached its greatest eastern elongation (furthest position from the sun when viewed from Earth). It is still moving closer to us now, but as it does so, less surface is illuminated. Venus appears very bright  because although it is less than a quarter crescent, it is so close that the illuminated area appears large from Earth. A small telescope should give a view similar to this over the next few weeks as the brightly-lit area slowly becomes smaller. By the middle of August it moved between us and the sun, so disappeared.

A 100 second video (5 frames per second) was made, and is available here. Of these 500 shots the best were selected and stacked with Registax software to produce the photo above.

With Venus low in the sky it was photographed through a thick and turbulent atmosphere just above the city. The disturbance of the view that resulted is apparent in the video.

COMET LOVEJOY

This photograph was taken on 9 January 2015 as Terry Lovejoy's fifth comet moved into Taurus. It was not easily visible in the city's light pollution, but showed up in binoculars as a fuzzy blob about a third of a degree across. Dusty comets produce the most bright tails, this one is not releasing much dust, yet a faint tail can be seen below it. It passed closest to Earth on 7 January. In most photos the nucleus appears circular. Five 3-minute shots were taken and combined to make this image. During those fifteen minutes the comet moved enough to make to appear slightly oval.

The summer constellations of Orion, Taurus and Gemini dominate the night sky early in the year.  The photograph below shows boys setting up a dobsonian telescope to observe Jupiter low in the northeastern sky (3 February).

The best deep sky object is the great nebula in Orion, which was also observed.

This photograph was taken through the Meade telescope in February 2014 using a Canon 60Da DSLR camera which is designed to take astrophotographs, so does a better job than a regular camera.

 

Close to the great nebula is one which is difficult to see in light-polluted areas. The running man nebula is a combination emission and reflection nebula. In the middle there is a dark feature which appears to be a man running along with his arms spread apart.

If you live well out of town and have dark skies see if you can  find the running man with binoculars.

Total Lunar Eclipse

On 15 April 2014 there was a total lunar eclipse, which had begun before the moon rose in the east.

Above the eclipsing moon was the bright star Spica, and Mars was shining in the northeast.

This was taken at 7-30pm, about fifteen minutes before the eclipse was total.

The shot on the left was taken at about 7pm, by which time the shadow of the Earth was covering most of the moon.

The last photograph shows the moon at 7-45pm, when it was at maximum eclipse. It is never completely dark because the sunlight passing through the Earth's atmosphere is scattered. The red end of the spectrum falls on the moon, the blue end being lost to space.

Globular star clusters are interesting deep-sky objects. This is Omega Centauri which is the brightest of all. It is also close at just 16,000 light years and contains about a million stars. The binocular view looks like a large oval cloud.

This photograph was taken with a Mintron camera through a Meade telescope on 5 April 2013. Until then the cluster did not rise high enough above the horizon until late at night. Through the winter it will be easier to find.

The southern hemisphere globular cluster, 47 Tucanae is one of the most impressive. It is easy to resolve in small telescopes and bright enough to be visible to the unaided eye, just to the west of the Small Magellanic Cloud. It is in the constellation Tucana the Toucan and the second brightest cluster after Omega Centauri.

This photograph was taken on 9 February 2013 as the cluster sank lower in the southwestern sky.

Most star clusters are open clusters. They are described according to objects they resemble, although they usually do so remotely. This photograph shows Sirius, the brightest star in the sky. The full moon is nearby so the sky is light. To the right is the open cluster M41 (or Little Beehive). It is made up of about 75 stars and looks like a skep (dome-shaped straw beehive) with bees streaming out if it. A very easy cluster to find with a small telescope.

Probably the best known deep-sky object in the Southern Hemisphere is this open cluster. It is the Jewel Box. A bright group of stars which lies just outside the Southern Cross. Easy to spot with binoculars, it is next to Mimosa (the second brightest star of the Southern Cross). Even the city lights do not diminish the impact of this cluster.

 

14 November 2012      

Partial Solar Eclipse

This photograph of the moon passing between the sun and the Earth was taken at 10.30am when the eclipse was at maximum (most of the sun was obscured). We will not have another eclipse as full as this for thirteen years.

About 80% of the sun is hidden by the moon. In northern Australia the eclipse was total, but the sun was not completely hidden from any site in New Zealand.

 

6 June 2012

Transit of Venus

One of the rarest events in astronomy did not occur in the twentieth century, and will not be seen again until the twenty-second century (in 105 years from now). This is the passing of the planet Venus between Earth and the sun. It was a wet day in Palmerston North on 6 June, but at 4.20pm, just before the transit finished, the cloud lifted slightly and this photograph was possible. It shows Venus just minutes before it passes from the face of the sun.

 

6 May 2012       SUPERMOON

This is a shot of the biggest full moon of 2012 as it rises over the PNBHS College House dining hall. The nearest point in its orbit around the Earth has coincided with the full phase of its cycle. That creates a perigee-syzygy, but 'supermoon' is easier to say.

Here it is thirty percent brighter and fourteen percent bigger than average.

It is 356,955km from Earth. The mean moon-Earth distance is about 384,400km.

This photo of Jupiter was taken at 9pm on 6 September 2009. Over 1000 shots were taken (5 per second) and recorded on a laptop.  These were stacked using Registax software to produce this result.  One of Jupiter's Galilean moons (Europa) can be seen to the left.

The light coloured regions are zones and result from upward moving atmosphere.  The dark parts are belts of downward sinking material.  The boundaries between them are bands and the turbulence there results in blue festoons and brown cyclones, particularly near the equator.  The most easily recognised feature is the Great Red Spot, which is actually a light orange cyclone twice the size of the Earth.  The key below points out these features.  This second photo was taken 30 minutes later, notice that the planet has rotated slightly to the right.  It only takes Jupiter 10 hours to make one complete turn, compared to our 24 hours.  This fast rotation is the reason the planet is wider than it is tall.

 
jeremy.jpg (28204 bytes)

When using a telescope it needs to have the small finder scope on the side accurately set so we can easily identify what we want to view.

This is done during the day by lining the telescope up with the top corner of a building and adjusting the cross-hairs of the finder scope to match.

 

LUNAR LANDSCAPE

Here the moon is 81% lit.

The details of the surface are easiest to see along the terminator (boundary between light and dark). This photo was taken because the most prominent crater of all (Copernicus) is near the middle of the terminator. You can see the rays of ejecta blasted out from the impact which formed this crater.

Copernicus is 93 km wide
and nearly 4 km deep.

moon2.jpg (5654 bytes)

The dark patches are basaltic lava flows, evidence of the moon's volcanic past.

The photo at left was taken through a small telescope. A pair of binoculars should give similar detail.

The photos on this page were all taken from Palmerston North (in the Southern Hemisphere). This is why the moon is upside down compared to the Northern Hemisphere views found in most books. We cannot see a "man in the moon", but there is a rabbit!  Look for it and its long ears on the left of the moon above.

CURRENT MOON

For those wanting to recognise the stars and planets there is an excellent resource available at www.cybersky.comThis freeware programme will turn your computer into a planetarium. It shows a labeled view of what the sky looks like now, or almost any time in the past or future. It is ideal for learning the names of the stars, constellations and planets. Just print out the map, then go outside and identify everything.

For those interested in satellite-watching visit www.heavens-above.com This site will tell you when and where to look to see the next bright satellite pass over your place.

Click here to return...