Night Sky Course – Lecture 2- April 8 2016

Mississippi Valley Night Sky Conservation:
‘Observing the Night Sky Around Us’:

Night Sky above Mississippi Mills Apr 8 2016 -courtesy stellarium

Program developed by:

  • Mississippi Valley Conservation Authority in partnership with:
    • Royal Astronomical Society of Canada
    • Ottawa Astronomy Friends
  • Instructor: Pat Browne
    • Assistant: Shawn McKay
  • References used in this course References
  • Course runs Fridays: April 1, 8, 15, 22, 29.
  • Note: Donations can be receipted as charitable – best to write a cheque so that we have proper name and address information (mark it as NightSky donation). Donations can also be made on-line to Mississippi Valley Conservation via canadaHelps Choose Night Sky Conservation fund
  • Course time: 7:45 – 10:00 formally with priority given to observing when clear sky . (We may choose to observe on a clear night other than Friday due to weather patterns)


– Andrew Lindstrom Siberia, Akademgorodok (Not exactly around us… 🙂
    • Explore the Universe Program Explore the Universe Exercises for Certificate
    • exploreDeepSky
      Annotated image for Andrew, our foreign correspondent . Mar. 5 2016, Andrew Lindstrom our former Night Sky Assistant asked for annotations:
    • Constellation Taurus and the Hyades Open Cluster
    • Constellation Orion and the Great Orion Nebula
    • Sirius – the Dog Star (Canis Major) Brightest Star
    • Meteor Note: The sporadic meteor in the image is apparently part of a swarm that happens during Spring Equinox. The reason why is still unknown (no identifiable parent Comet), but one hypothesis is that more space debris litters this section of Earth’s orbit. Meteors are debris from space.  As these objects enter Earth’s atmosphere (small particles), they vaporize due to friction with the air See Nasa meteor network
    • Star charts and Spring Observing Exercises: springObserving doc
    • Handouts and Tools
    • Logbooks and handbooks
      • Observer’s Handbook – RASC
      • Isabel Williamson Lunar Observing
      • Beginners Observing Guide – RASC BOG
      • *YOUR* Logbook (Without a logbook you’ll always be a beginner)

Some ‘reflections’ from our Observing Session …

Using a simple reflector

Here is a simple reflector with a tripod and an altitude/azimuth mount.
A reflector telescope has 2 mirrors: the primary mirror which collects all the photons of light, and the diagonal secondary mirror that directs that beam of photons into your eyepiece to be magnified and ‘absorbed’. The telescope is equiped with a ‘finder’ that needs to be aligned on the same optical axis as the eyepiece in the telescope. The finder is used to ‘Star Hop’ to bright stars so that we can find the deep sky objects in our telescope eyepiece.

How to Set-up your Finder so that you can ‘Star Hop’

We learned How to line up the telescope:So that we can find things using the smaller spotting scope (we call it the finder). Once we know that our finder is looking at the same point in the sky as the eyepiece. Here is a sketch of a reflector telescope with a finder.

  • Finders typically have cross-hairs to center a bright star. They are mini-telescopes that produce low magnification.
  • You can also use other spotting devices like LED red-dot TelRads or even an arrow with flourescent paint and a small magnifying lens lined up on the optical tube.
      • The principle is the same: Find the bright object, such as a first magnitude star, planet or even the moon in a low power eyepiece and then center the same object in your finder.


    • You may have to adjust set screws or orient the pointer in some way
    • Once the object is aligned in the center of your finder thanks to your eyepiece, you can find other objects just using your finder.

Find things by moving the telescope using the motion controls:

    • The principle is the same for adjusting your telescope altitude and azimuth.
    • Use a low power eyepiece to find the object, use your coarse adjustments to move the scope in altitude and azimuth (or if you have an equatorial mount, in Right Ascension and Declination)
    • Then to keep the object centered, you use fine motion control or just ‘nudge’ the telescope

We learned how the rotation of the earth moves these objects out of our eyepiece or ‘field of view’

  • Telescopes magnify the field of view through the eyepiece. So we have very small fields of view, and it is hard to find objects unless they are big and bright.
  • We use the moon or planets to be able to sight along the telescope and find it in the small eyepiece.
  • The earth rotates on its own axis in 24 hours. That represents a rotation rate of 15 degrees per hour or 60 minutes. Divide 60 minutes by 15 and we are turning at the rate of 1 degree every 4 minutes. If we are not paying attention, when we look into the eyepiece we will see that the object has indeed been carried along in the sky… or that the earth has rotated underneath our feet!All objects that we view in a telescope will drift out of the eyepiece according to the sidereal rate. Motorized mounts to counter the earth rotation are used when we wish to track the object for imaging and spectroscopic data.

Let’s look at our Observing list for Early Spring Observing: springObserving doc

April 4 2016 Night Sky Tour with OAFs (Ottawa Astronomy Friends):

Guest Scope Support OAFs: see OAFs (Ottawa Astronomy Friends) Conversation
Ottawa Astronomy Friends: Attilla, Richard and Ingrid:

Here is the annotated version of our Night Sky Tour (incomplete as it went on for a few hours…)
Constellation IDs – Auriga (the funny pentagon thing) Taurus, Canis Major, Canis Minor (because of Procyon) Orion, Gemini, Cancer, Leo, Coma, Ursa Major
Many folks brought their planisphere- great to see them use it!
When observing nebulousity in the eyepiece for the first time, the trick was to ‘look without looking’. I found that if I placed the object off center, it was easier for people to ‘look and really see’

We did an aligning exercise using the brightest thing available – Jupiter with 4 moons . Ingrid was a great teacher using her 4″ and finder with cross-hairs.

1. Taurus – M45 -Pleaides
2. Taurus – M1 (wide field is nice to find it)
(Congrats to Ingrid – my 6″ is used to getting it – but her 4″ at (6^2/4^2) or 1/2 the light gathering, displayed it nicely).
3. Orion – M42
4. Gemini – M35 and 4x further NGC 2158
5. Castor (although designated alpha – it is the dimmer one – and with small scopes – separations tooo close – a few arc-seconds. – need higher power and good focus)

South / Spring
1.Cancer – M44 Beehive Cluster
2. – M67
(Naked eye – although the constellation was not)

M67 reinforced the ‘averted vision’ technique of looking at distant and whispy things (2.9kly vs .5kly)

3.Leo – M65/66 and that NGC,,,
Great to see it in 3 scopes!

4. Coma Star Cloud Mel 111
– Not dark and south enough yet
4a- Thanks to Richard! – M104 Sombrero

Towards East
1.M3 – Globular Cluster
Found at 30x – got too cold to go for higher power eyepiece.

2.Ursa Major – Galaxies M81/M82
Thanks to Richard !

I find this one different from the orientation I’m used to…
3. Alcor Mizar double
(not tonight)

Attilla’s M51 with anti-UHC filter was ‘vaux le voyage’… Up to the heaviside layer. Never have I seen such spiral structure (with extra blue-light content!)
We could augment the list…with whatever else was seen as the night progressed…