Saturday, July 7, 2012

How to use the SFA star chart–Malaysia

How to use the SFA star chart – download it here at http://observe.phy.sfasu.edu/SFAStarCharts/SFAStarChartsAll.pdf

A star chart can be confusing at first with the dots and strings - no worries. For Malaysia we usually just use the 2nd and 3rd 'Equatorial Region' star chart.
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1. Look at the upper scale, the one with the dates and search for the date today. Then, look downwards at the constellations - the ones that are directly below the date are the ones that appears directly on top of your head on 8p.m..
Meridian on celestial sphere.png
What does ‘meridian’ means? It simply means an imaginary line that splits the sky into the East and the West. Knowledge of your orientation is very important during observation of the night sky. So what’s under the dates shows the constellations that are on the centre of the sky during 8p.m. Be prepared to search for a wider field as illustrated, not just one or two stars.


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If you’re observing at other times, just move the red rectangle 15 days forward per hour after 8p.m. For example, if you’re observing at August 6, 12a.m., move the ‘rectangle’ to October 6th.

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2. Hold your star chart upright and face North. Find a constellation where the stars are brighter (larger black dot on the chart), then look up and search for the constellation. An easy target to start with is Orion or Scorpio - either one can be observed throughout the year.

The left scale, ‘declination’ shows where the constellation will be in the night sky. The ones on declination zero will be at the centre. The ones towards the negatives will be on the southern side, the ones towards the positives will be towards the northern sides. For example in this Stellarium snapshot, you can see the constellation Ophiuchus on the line marked ‘Declination zero’. You can also see that it is also on the Meridian on 11p.m. on July 6th.
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Once you gauge the approximate positions of the constellations, you will begin to identify more of the constellations. A good training is to download the Stellarium application at www.stellarium.org and practise identifying the constellations using the star chart and disabling the lines.

Once you’re there - Congratulations, you've acquired the most important skill for stargazing.

1 comment:

  1. I would like to ask which constellation will be available around June in Malaysia?

    ReplyDelete