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The Sky This Month - June 2008

Posted in
Written by Gary Boyle, Ottawa on
Post Date: 
Wed, 2008/06/04

Star Light…Star Bright

My favourite part of the day is sunset. As time marches on and if the sky is clear, I enjoy watching pastels of blue get progressively darker. As the sky is dimming, I try to catch stars as they start to show themselves one at a time. In June however, this game is short lived as brilliant Arcturus is the first to pop out, barring the obvious Moon or bright planets. Referred as alpha star in the constellation Bootes (the herdsman), it is the third brightest star seen overall after of course the Sun. But if it already dark and you have trouble recognizing it for the first time, take the curved handle of the Big Dipper and follow as it arks to Arcturus. In fact, keep moving south with this curve and you stumble onto the bright star – Spica in the constellation Virgo. Spica is 15th on the list.

Arcturus is a K1 red giant star located at a cosmic stone’s throw distance of 37 light years (ly). In fact, you can line up 16 Suns across the equator of Arcturus, keeping in mind that 109 earths fit across the Sun. This star is peculiar in the sense that its light spectrum is giving off lots of emission lines and its output is close to 180 times that of the Sun.

There are a few wonderful double stars associated with Bootes. Kappa Bootis for instance is made up of two colourful stars of magnitude 4.6 and 6.6, separated by 13.5 arc seconds. In a low power eyepiece, include Iota (one full moon) to the south. Epsilon Bootis is another striking pair of gold and blue but only with a 2.9 arc second gap. They rotate around each other in 153 years. Epsilon also takes on the name Izar of Pulcherrima.

 

 

As for objects, the constellation is littered with galaxies mostly on the faint side and has no bright Messier objects. About 30 galaxies are 13th magnitude or brighter. Unfortunately most are round galaxies without structure. There is however NGC 5523, a 13th magnitude edge on galaxy. Photography will reveal a hint of arm structure.

A bright almost edge on galaxy with a bright core is NGC 5899. This pancake of stars has nice detail in its arms but only measures 3.2 X 1.2 arc minutes. NGC 5899 is the brightest within a group of galaxies including NGC 5893 and NGC 5895/96.

Next, try to hunt down another detailed spiral - NGC 5248. Although it resides within the borders of Bootes, it is actually part of the Virgo cluster. NGC 5248 measures 6.2 X 4.5 arc minutes and glows at magnitude 10.2. It is an estimated 50 ly from us. The only globular cluster within the confines of Bootes is NGC 5466. Nothing impressive her as it is a magnitude 9.2 unresolved, dim globular.

We will not slide over to east and enter Serpens the serpent. A funny and unique orientation in the sky as the constellation appears in two parts. Serpens lies to the west of Ophiuchus while Serpens Cauda is to the east. There is one Messier in Serpens that is M5 and what a gem it is. At 24,000 ly from us and with an estimated age of 13 billion years, it is believed to be one of the oldest globulars in our galaxy. Before leaving this area, check out NGC 5951. Its orientation is close to edge-on and its magnitude is 13.1. There is some detail in the spiral arms. Large scopes will reveal this structure.

 

 

 Switching to the other side of Ophiuchus, Serpens Cauda is home to M16 the Eagle Nebula. This emission nebula is a favourite at star parties and is the famous Hubble Space Telescope picture of the “Pillar of Creation”. M16 is 7,000 ly away and is about 20 ly in diameter. It is just at naked eye visibility and is a treat even in binoculars.

The King of Planets - Jupiter opens this month by rising in the south east at midnight locally and well on its way to the July 9th opposition when it will be visible all night long. From time to time you will witness through a telescope the tiny black dot of a moon’s shadow crossing Jupiter. These transit timings can be found starting on page 215 of the 2008 RASC Hand Book.

Venus is too close to the Sun to be seen safely. It is behind the Sun on June 8th and slowly moves into the evening sky and will be a summertime treat.

We have a celestial visitor low in the west. Comet Boattini was discovered at the end of May and will sneak under Sirius around June 11th. In fact it might get brighter from its current 6th magnitude status. The down side, it is low in the sky. We also have 10th magnitude nova in the constellation Ophiuchus.

 

Object

Type

Magnitude

Coordinates

M05

Globular cluster

13.1

RA:15h 18m Dec:+02d 05' 00"

M16

Emission Nebula

6.4

RA:18h 18m Dec:-13d 47'

NGC 5248

Galaxy

10.2

RA:13h 37m Dec:+08d 53'

NGC 5466

Globular cluster

9.1

R.A:14h 05m Dec:+28d 32'

NGC 5523

Galaxy

13

          RA:14h 14m Dec:+25d 23m

NGC 5899

Galaxy

11.8

RA:15h 15m  Dec:+42d 03"

NGC 5951

Galaxy

13

RA:15h 33m Dec:+15d 00'

 

Well, a piece of Canada is now on the Martian surface. On May 25th, the Phoenix Mars Lander successfully touch down in the red planet’s arctic. The 90 day mission is to look for signs of water, the question that has been puzzling scientists for a long time. Canada’s contribution is a 37 million dollar shoebox sized weather station. The mini station will record temperature, air pressure, cloud height, humidity and wind speed. Stay tuned to the Phoenix home page for mission updates.

And finally the Space Shuttle Discovery is now in orbit and docked with the ever growing International Space Station. You can track the mission via NASA TV as well as witnessing these extremely bright objects as they pass over you city.

Remember, summer solstice will occur on June 20th at 16:00 UT.

Until next month, clear skies everyone.

Gary Boyle