Observing

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Written by: Seanie Morris

Parent Category: Astronomy

Published: 18 September 2008

Created: 18 September 2008

Last Updated: 04 January 2014

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This annual Springtime shower peaks around the 22nd of April. This year, 2007, it will be after 10pm on Sunday night (22nd) when it will peak for observers in Ireland.


Background

The April Lyrids are the oldest recorded meteor shower, with Chinese records going back as far as c. 687BC. Although most meteor showers are associated with regular periodic comets to keep up annual displays, the April Lyrids are more associated with longterm-periodic comet Thatcher C/1861 G1, which takes around 415 years to travel around the Sun. Prior to this comets’ pass in 1861 (as discovered by Mr. A.E. Thatcher in New York), the Lyrids were still associated with this previously unknown periodic comet, but it would have only passed Earth 5 times in its recorded 2,600 year history.

Any meteor shower gets its name from the constellation in the sky where activity seems greatest. As Earth encounters a dust stream, a rise in meteor activity is called a “shower”. The known constellation closest to that peak as seen in the sky gives its name to that shower. Thus, the Lyrids occur in the constellation of Lyra (the “Lyre”, or “Harp”). There are a couple of showers in a year that occur in this general area, so this shower is called the April Lyrids.

The meteors themselves contained in this dust stream are classed as “medium fast”, in that they travel around 28 miles per second (100,000 miles an hour). Faster meteors travel around 36 miles per second (130,000 miles per hour). Lyrids number an average of 15 to 20 per hour when at maximum. Bursts in the past have numbered almost 100 per hour in 1803 and 1922, and a major burst of about 250 per hour in 1982.

A meteor itself is essentially dust and small solid particles of rock and sand left behind by the comet as it travelled through space. Coming from the depths of the outer Solar System where it would have been frozen at almost absolute zero, it warms up as it gets closer to the sun. Just like water ice in a hot saucepan melts and lets off steam, the same effect happens with the comet when its carbon dioxide ice sublimes from ice directly to a gas. As the gas is expelled, so too is any amount of attached rock and dust, leaving behind it a glistening trail of debris for the rest of time.


How and where to look

On Sunday night of the 22nd, look towards the northeast after 10pm. Low down near the horizon will be a bright blue-white star. This is Vega, and it the brightest star in this part of the sky that night (and 5th brightest overall). Vega is one of 5 key stars that make up Lyra. The other 4 lie beneath it in a small parallelogram shape. This is the area of sky t look for a rise in meteors. Lyra will rise higher as the night progresses, getting to its highest point almost directly overhead around 6am in the growing morning twilight. In the small hours of the morning, you will also see brilliant Jupiter shining brightly low down in the south.

All you need to observe meteors is a your eyes, and a comfortable chair. Your chair should have some reclining feature/posture to it to prevent you getting a crick in your neck while holding your head skyward! Wrap up warm, and bring a flask of soup or tea too – coffee can actually make your body feel cold quicker, as the caffeine amongst other chemical in it restricts blood flow to your extremities (hands, toes, nose and ears etc).

Then just sit back and enjoy the show!


-Seanie Morris.

Editors Note: Feel free to contact me for diagrams etc. associated with this article.

Details

Written by: Seanie Morris

Parent Category: Astronomy

Published: 18 September 2008

Created: 18 September 2008

Last Updated: 04 January 2014

Hits: 3149

Feel free to copy and paste this list into your text editor and print off for future reference.

M1 The Crab Nebula  supernova remnant in Taurus
M2 globular cluster in Aquarius
M3 globular cluster in Canes Venatici
M4 globular cluster in Scorpius
M5 globular cluster in Serpens Caput
M6 The Butterfly Cluster open cluster in Scorpius
M7 Ptolemy's Cluster open cluster in Scorpius
M8 The Lagoon Nebula diffuse nebula in Sagittarius
M9 globular cluster in Ophiuchus
M10 globular cluster in Ophiuchus
M11 The Wild Duck Cluster open cluster in Scutum
M12 globular cluster in Ophiuchus
M13 Great Hercules Globular Cluster globular cluster in Hercules
M14 globular cluster in Ophiuchus
M15 globular cluster in Pegasus
M16 open cluster associated with the Eagle Nebula or Star Queen Nebula IC 4703 in Serpens Cauda
M17 The Omega or Swan or Horseshoe or Lobster Nebula diffuse nebula in Sagittarius
M18 open cluster in Sagittarius
M19 globular cluster in Ophiuchus
M20 The Trifid Nebula diffuse nebula in Sagittarius
M21 open cluster in Sagittarius
M22 globular cluster in Sagittarius
M23 open cluster in Sagittarius
M24 Milky Way Patch star cloud with open cluster NGC 6603 in Sagittarius
M25 open cluster in Sagittarius
M26 open cluster in Scutum
M27 The Dumbbell Nebula planetary nebula in Vulpecula
M28 globular cluster in Sagittarius
M29 open cluster in Cygnus
M30 globular cluster in Capricornus
M31 The Andromeda Galaxy spiral galaxy in Andromeda
M32 Satellite galaxy of M31 elliptical galaxy in Andromeda
M33 The Triangulum Galaxy (also Pinwheel) spiral galaxy in Triangulum
M34 open cluster in Perseus
M35 open cluster in Gemini
M36 open cluster in Auriga
M37 open cluster in Auriga
M38 open cluster in Auriga
M39 open cluster in Cygnus
M40 Double Star WNC4 in Ursa Major
M41 open cluster in Canis Major
M42 The Great Orion Nebula diffuse nebula in Orion
M43 part of the Orion Nebula (de Mairan's Nebula) diffuse nebula in Orion
M44 Praesepe, the Beehive Cluster open cluster in Cancer
M45 Subaru, the Pleiades--the Seven Sisters open cluster in Taurus
M46 open cluster in Puppis
M47 open cluster in Puppis
M48 open cluster in Hydra
M49 elliptical galaxy in Virgo
M50 open cluster in Monoceros
M51 The Whirlpool Galaxy in Canes Venatici
M52 open cluster in Cassiopeia
M53 globular cluster in Coma Berenices
M54 globular cluster in Sagittarius
M55 globular cluster in Sagittarius
M56 globular cluster in Lyra
M57 The Ring Nebula planetary nebula in Lyra
M58 spiral galaxy in Virgo
M59 elliptical galaxy in Virgo
M60 elliptical galaxy in Virgo
M61 spiral galaxy in Virgo
M62 globular cluster in Ophiuchus
M63 Sunflower galaxy spiral galaxy in Canes Venatici
M64 Blackeye galaxy spiral galaxy in Coma Berenices
M65 spiral galaxy in Leo
M66 spiral galaxy in Leo
M67 open cluster in Cancer
M68 globular cluster in Hydra
M69 globular cluster in Sagittarius
M70 globular cluster in Sagittarius
M71 globular cluster in Sagitta
M72 globular cluster in Aquarius
M73 open cluster in Aquarius
M74 spiral galaxy in Pisces
M75 globular cluster in Sagittarius
M76 The Little Dumbell, Cork, or Butterfly planetary nebula in Perseus
M77 spiral galaxy in Cetus
M78 diffuse reflection nebula in Orion
M79 globular cluster in Lepus
M80 globular cluster in Scorpius
M81 Bode's Galaxy (nebula) spiral galaxy in Ursa Major
M82 The Cigar Galaxy irregular galaxy in Ursa Major
M83 The Southern Pinwheel Galaxy spiral galaxy in Hydra
M84 lenticular galaxy in Virgo
M85 lenticular galaxy in Coma Berenices
M86 lenticular galaxy in Virgo
M87 Virgo A elliptical galaxy in Virgo
M88 spiral galaxy in Coma Berenices
M89 elliptical galaxy in Virgo
M90 spiral galaxy in Virgo
M91 spiral galaxy in Coma Berenices
M92 globular cluster in Hercules
M93 open cluster in Puppis
M94 spiral galaxy in Canes Venatici
M95 spiral galaxy in Leo
M96 spiral galaxy in Leo
M97 The Owl Nebula planetary nebula in Ursa Major
M98 spiral galaxy in Coma Berenices
M99 spiral galaxy in Coma Berenices
M100 spiral galaxy in Coma Berenices
M101 The Pinwheel Galaxy spiral galaxy in Ursa Major
M102: Lenticular galaxy (the Spindle Galaxy NGC 5866) in Draco ?
Duplication of M101 in Ursa Major?
M103 open cluster in Casseopeia
M104 The Sombrero Galaxy spiral galaxy in Virgo
M105 elliptical galaxy in Leo
M106 spiral galaxy in Canes Venatici
M107 globular cluster in Ophiuchus
M108 spiral galaxy in Ursa Major
M109 spiral galaxy in Ursa Major
M110 Satellite galaxy of M31 elliptical galaxy in Andromeda

Details

Written by: Seanie Morris

Parent Category: Astronomy

Published: 18 September 2008

Created: 18 September 2008

Last Updated: 04 January 2014

Hits: 2846

(Originally printed for local newspapers Feb 2006)

As we come out of winter, more astronomers are prepared to leave the warmth of their homes to look at the splendours of the Universe. Shame on you! Winter provides some of the best opportunities to see these wonders! Nevertheless, spring means that summer is not far ahead, and that means more pleasant viewing conditions.

While a lot of the winter constellations offer more to see within them, most of them will remain visible for a month or two yet. Orion, Gemini, Leo, and Virgo, all rich with nebulae, star clusters, and galaxies, will still remain on view till April or May at best. Not forgetting the circumpolar constellations, all these have at some stage, something brilliant worth aiming a telescope at.

It is also worth to note that by now, many people who received a new telescope for Christmas recently, will be getting used to using their new toy. But, there is still a lot to learn in maintaining and maximising the use of that toy. For now, let me talk to you about what to look for. And since many people availed of the telescopes on offer before Christmas such as the Skylux 70mm, and the Meade ETX-70, I’ll start with these telescopes in mind. Also, have your star atlas nearby!

Lets Go
If you go out tonight (or any night) when its dark and look up above, you should see three bright stars in a bent line. They cover an area about the same as your flat hand held in front of your eyes at arms length. One of the stars will appear a little brighter, and more white that the other two bright blue stars. This white ‘star’ is in fact Saturn, while the other two are Castor and Pollux, the heads of the twin brothers of Greek mythology that make up Gemini. This constellation actually looks like two stick men standing side by side holding hands.

Saturn is tilted favourably towards Earth in such a way that the rings are unmistakeable, even in a small 70mm refractor telescope. If you have one or similar and look at Saturn, you should see the disk surrounded by the rings as a solid bright shape. Larger telescopes will show a little more detail, with an 8 inch reflector and larger showing slightly more colour, and the famous Cassini Division – a large gap in the rings. No one forgets their first look at Saturn in a telescope!

Below Gemini towards the horizon is a very bright star, twinkling from blue to white. This is Sirius, the brightest star in the sky, and lies in the constellation Canis Major, the Greater Dog. If you focus your telescope on it and watch it for a minute, you will see it goes through many changes in colour from blue to red to white to orange. This is not a natural effect of Sirius – it is an effect caused by its light going through our turbulent atmosphere. If we had no atmosphere, Sirius would be brighter, and almost pure white.

Soon, Sirius will move closer to the horizon and fall below, only to be seen by those further south of our latitudes until it comes into view again next November.

Back at Saturn
To the left of Saturn and moving away from Gemini is a small constellation called Cancer, The Crab. Within Cancer there is a small cluster, known as Praesepe, or  M44 - The Beehive Cluster. This cluster is easily seen from a dark observing site with little or no light pollution. More experienced observers will see it from towns or suburbs by knowing where to locate it. This cluster is composed of many tens of stars held loosely together by their own gravity – an Open Cluster. It lies within our own Milky Way galaxy, but can be thought of as a mini galaxy within it.

With the naked eye, you can see a couple of stars within a small cloudy area. If you point your telescope at this tiny cloud, you will see many stars within the cluster. The bigger the telescope, the more stars you will see. You can try and count them, but you’ll be there for a long time doing so!

Moving on, if you draw an imaginary line from Saturn to The Beehive and keep going, you will come to the constellation of Leo, The Lion. You have probably heard of this constellation in recent years as the source of the famous Leonids Meteor Shower every November 17th. Leo itself takes on the shape of a lion sitting on the ground. The front paws and head make a shape know as The Sickle. It is just off the sickle that the radiant for the Leonids lies.

At Leo’s front paw is a bright blue star. This is Regulus, meaning Prince, or Heart of the Lion. Along Leo’s flank moving left, you pass a star marked simply as theta Leonis. A small bit further on again, you come to another bright star called Denebola, marking the tail end of Leo. With your telescope, if you slowly sweep the area half way and a little below between Regulus and  theta Leonis, you might encounter some very faint small blurry objects. If you have nice viewing conditions and keen eyesight, you should see 3 really. These are distant galaxies M95, M96, and M101. A little to the left and below theta Leonis itself are 3 more galaxies, M65, M66, and NGC 3628. If you can spot these with your 70mm refractor, imagine what you could see with a 6 inch reflector and larger.

The Messier Catalogue
Where do we get the M-numbers from? We credit this to the French astronomer, Charles Messier (1730-1817). In a bid to try and find comets with a small and rather poor refractor, he came across many objects not catalogued before. Since they did not move, yet he did not have the optical power to see what they really were, he compiled a list of 110 objects he found not to be comets. These were numbered and given an ‘M’ prefix. This catalogue is known at the Messier Catalogue.


The King
Not far away from the left and below of Leo is a brilliant steady white point of light. This is Jupiter, the largest planet in the Solar System. This is a favourite target among amateur astronomers, even those with nothing more than a pair of binoculars. From night to night, you can see 3 or 4 of Jupiter’s moons big enough to be seen from Earth. In order of size they are Ganymede, Callisto, Europa, and Io.

If you manage to get a couple of clear nights in a row, spend at least a few minutes each night looking at Jupiter. You will notice that these 4 tiny points of light, even in binoculars, move around Jupiter. With your 70mm refractor, you should be able to see 2 coloured bands or cloud belts across Jupiter. A larger telescope will show more. A larger telescope will also show the Great Red Spot. This massive storm, 3 times as big as Earth, was first seen by Galileo over 400 years ago, and is still bellowing! If you look at Jupiter a few hours apart, you will notice the Great red Spot moving across the planet. It completes one revolution every 9.8 hours.

(Paragraph here mentioned about the forthcoming TAS meeting at the time in order to find more info.)

Clear Skies!