Transcript astrocoursespring2012lec1-1-5

Spring 2012 Astronomy Course
Mississippi Valley NightSky Conservation
The Sky Around Us
Program developed by
•Mississippi Valley
Conservation Authority
•Royal Astronomical Society
of Canada
•Ottawa Astronomy Friends
Instructors:
Pat Browne
Stephen Collie
Rick Scholes
Earth Centered Universe
software for illustrations –
courtesy David Lane
Lectures combined with
Observing
Course runs each Friday during the
month of April and the beginning of
May
Course time: 19:30 – 22:00
formally with priority given to
observing when clear
5 lectures covering observing the night sky:
I
Celestial Sphere and our place in it
II
Stars within our galaxy,
binary systems, variable stars, dying stars (‘planetary
nebula’)
III Star clusters Open Clusters within the disk of the Milky
Way, Globular clusters , in a halo around the Milky
way
IV
Galaxies
V Observing stellar and non-stellar objects, galaxies,
clusters of Galaxies,
•
and always … Observing Techniques:
•
•
•
star charts
astronomy applications
logbooks and handbooks
•
Postings for the course, and discussion group are at
the Mill of Kintail Night Sky Conservation Yahoo
Group. You can join here:
http://tech.groups.yahoo.com/group/MoK_NSC
•
Course Notes available
at
www.millstonenews.com/the-night-sky
Activities
Activities will include …
Moonlit walk to Fred
Lossing Observatory
Dark sky observing
Guest speakers
*Sanjeev Sivarulrasa
astro-photographer
Videos
Night Sky Conservation
ByLaw 03-62 in partnership with MVC NightSky
Conservation, and the RASC
NOW WHEREAS, properly
designed light fixtures do not
emit undesirable illuminating
light rays up into the night
sky and thus protect the
nighttime environment
NOW THEREFORE the
Council of the Corporation of
the Town of Mississippi Mills
ENACTS AS FOLLOWS: The
Outdoor Illumination By-Law
for
Mississippi Mills for the
regulation and standards for
responsible lighting, light
pollution abatement, and the
conservation of the night sky
environment.
CONSIDER THIS...
Our Dark Sky Site –
Long History of Looking up
Mississippi Mills is the home of
the Fred Lossing Observatory
(FLO) maintained and operated
by the Royal Astronomical
Society of Canada (RASC).
Located at the Mill of Kintail
Conservation Area, it was built by
the scientific community with
high-quality optics from the
National Research Council of
Canada.
Thanks to the continued
preservation of the night sky at
the Mill of Kintail, the local dark
skies have permitted the visual
discovery of 5 comets, making
FLO the only observatory in
Canada to do this
Comet Garadd
click on this link to download movie (19 MB)
:
http://millstone.typepad.com/files/garad2-2.avi
Lecture 1 The earth in space
StartShip Earth within its
Celestial Sphere
• The sky in different
seasons
• Planetary and comet
observations (those
objects which grace
our skies only
temporarily)
• Navigating around the
sky – knowing when to
observe objects and
where to look
The closest objects to us...
The solar System … planets Mars (right) and Saturn (left)
Celestial Sphere
The celestial sphere is an
imaginary sphere The
concept of the celestial
sphere provides a simple
way of thinking about the
appearance of the stars,
and other celestial objects
from our location on Earth
without the complication of
a realistic model of the
universe.
The position of a celestial
object is given by its Right
Ascension (RA) and
Declination (Dec) in the
same way as our position
on earth is given by our
Longitude and Latitude.
We can locate the celestial
object, like the star
Regulus in Leo by
specifying its RA and Dec.
It is visible in the
springtime along with the
galaxies in Leo, such as
M65 and M66
M65, M65
Galaxies
Earth Rotation – Night and Day
Earth Orbit - Seasons
Day and Night around the year
As we stand on the earth looking up
½ of the hemisphere is obscured by the
earth itself.
As the earth orbits around the sun in the
year, the night-sky will contain different
objects, different constellations.
What we see in the sky depends on
1.
Time of Year (and what is our nighttime view when our Time of Day is
after sunset)
2. Our latitude on earth: This sets our
horizon, and what is above or below
it when we look up at night.
Objects below the horizon cannot
be viewed. Certain celestial objects
remain permanently below our horizon.
Earth orbit and Tilt –
Seasons and star fields…

We do not see the same objects in
the sky day after day due to our orbit
and tilt. To understand this better
watch this video that explains the sky
at different points in its elliptical orbit
… and at different times of year in its
cyclical , tilting traversal around the
sky…. see A Year on Earth…
http://www.youtube.com/watch?v=IhqzW97_47w&feature=relmfu
double click or if that fails, copy and paste this link into your
browser
-minor errata They point to the cross-over point of the analemma as the
the equinox. This is not the case. The equinox occurs halfway
between the most northern, and south excursion of the Sun
So we can see that our orbit takes us
around the sidereal year where we
see different constellations and
different objects like stars, star
clusters and galaxies within these
constellations as we travel around
our orbit
What we can see in April …
The celestial sphere presented in this lecture
is set for April 13 2012 at 10 pm
•
Mars and Jupiter are visible
•
Bright stars can be identified such as
Regulus in Leo
•
Open clusters such as M44, the
magnificent Beehive cluster – visible
naked eye!
•
Globular clusters are less abundant
due to where we are looking in our orbit
. We have to wait till the summer to
view such knots of stars as seen in the
summer portion of the Milky way
•
Next time we will see the celestial
sphere has turned a bit. We will notice
this as we look up!
constellation Leo
The Observers Handbook of the
RASC (Royal Astronomical Society
of Canada) has tables of objects
visible for our location for different
times of the year.
The Observer’s Handbook Edition
includes data from 17 of the
astronomical object catalogs printed in
the Observer’s Handbook. The
catalogs included are:
1. Brightest Stars
2. Nearest Stars
3. Double and Multiple Stars
4. Colored Double Stars
5. Carbon Stars
6. Open Clusters
7. Globular Clusters
8. Galactic Nebulae
9. Messier Catalogue
10. Finest NGC Catalogue
11. David Levy’s Deep Sky Gems
12. Deep Sky Challenge Objects
13. Southern Hemisphere Splendours
14. Dark Nebulae
15. Nearest Galaxies
16. Brightest Galaxies
17. Radio Sources
Astronomical Cataloguing …
(A historical note)
What’s the M in M1, 2, … 109?
A contemporary comet hunter, David Levy
writes…
Fuzzy objects that are not comets lurk all over
the
sky . They are beautiful to watch, but for people
who search for comets they can be viewed as an
inconvenience; comet discoverer Leslie Peltier
called them “comet masqueraders.”.
At the end of 1758, Charles Messier found a
fuzzy patch around Zeta Tauri.
As he studied it from hour to hour and from night
to night, he found that the faint fuzzy object
stayed plastered to the sky; even though it
looked
like a comet, it never moved like a comet
Deep Sky Objects, David Levy, p. 24
There are other catalogues,
but the Messier catalogue is the best one
to start with!
M1
Nomencalture for Earth Centered Universe (ECU)
Double and Multiple Stars
Example: Porrima (Gamma Virginis)
Open Clusters
Example: M44, Beehive Cluster
Globular Clusters
Example: M53, Coma Berenices
Brightest Galaxies
Example: Leo Galaxies,
M65, M66
Mars
As the Earth Turns –Tour of the Night Sky
April 13 2012, 9pm EDT
N/S line - Meridian
M44
M67
When planning your are observing
session , start with the things that are
going to set first – Westward HO!
Here is the ECU view of the celestial
sphere showing the western sky,
You can see this on your planisphere.
But your planisphere does not record the
planets because they change from year to
year. ECU can program the planets in…
Jupiter, nearly set…
Venus (the brightest object)
We shall see a phase on Venus
Constellation Object
---------------- --------Taurus
M1 Crab Nebula – Supernova remnant
Taurus
M45 – the Pleaides – setting…
Gemini
M35 – Open Cluster
Auriga
M37,M36,M38 OCs
Orion
M42 Orion Nebula Emission, M78
M46,M47
M38
M1
M78
M42
We finish the Western tour with ruddy Mars
which is culminating on our meridian.
Venus
Venus
M45
line of the planets
(ecliptic)
Reflection Nebula
Monoceros M46, M47 OCs
Cancer
M44 Beehive Cluster , M67
M37
M36
M35
horizon (west)
Jupiter
As in 2004, 8 years ago, this season we
can see 4 naked eye planets…
venus
mars
jupiter
(set)
saturn
View - Southern horizon
Turning to the South…
M81,M82
Constellation Object
---------------- --------Leo
M65,M66
Galaxy pair
Canis Venatici M51 Whirlpool Galaxy
M3 Globular cluster
M51
M3
Ursa Major M81,M82
peculiar galaxies
oh, and planets Mars(again) and
Saturn …
PostScript: Many people are
imaging Mars as we observe. If you
see
a feature like the South Polar Cap,
you might be able to see it at:
http://www.christone.net/astro/mars/in
dex.html
M65,M66