The Messier Objects As A Tool in Teaching Astronomy

(1)

The Messier Objects As A Tool in Teaching Astronomy

Dr. Jesus Rodrigo F. Torres

President, Rizal Technological University Individual Member, International Astronomical Union

Chairman, Department of Astronomy, Rizal Technological University Graduate School

(2)

Research Problems

a. What are the best methods of teaching Astronomy through the Messier Objects?

b. Should the Messier Objects be shown to the students at random or in any pre-arranged order?

c. In addition to telescopes, what other methods would be useful in better understanding the Messier Objects?

d. What the principles or concepts that are best taught with each Messier Object?

e. What are the best locations to conduct studies of the Messier

Objects?

(3)

Research Objectives

This research has the following objectives:

a. To find out the best methods in teaching astronomy through the Messier Objects.

b. To find out whether the Messier Objects are best taught at random or through a planned or pre-arranged order.

c. What telescopes and other devises should be used for instruction?

d. To find out the principles and concepts that could be best taught with each Messier Object

e. To find out the best locations in conducting studies and

observations of the Messier Objects.

(4)

Research Methods

A good 4-inch telescope of whatever type would be enough for the study of the Messier Objects if one is observing in a dark site.

I have seen all of them with my 4.25-inch Astroscan in Puerto Galera, and my audience was pretty much impressed with the brighter objects and could even see the fainter galaxies.

The 12-inch Newtonian telescope, the biggest

telescope one can get, of the RTU Department of Earth

and Space Sciences. Telescopes with bigger apertures

gather more light and can detect fainter objects better.

(5)

Observing Sites

I have categorized three possible sites for observing Messier Objects with students.

a. The campuses of RTU.

a.1 Mandaluyong Campus a.2 Pasig Campus

b. Another site would be the suburban sites.

c. The dark site is perfect for observing the Messier

Objects

(6)

Telescopes and Other Equipment

Celestron 8-inch Schmidt-Cassegrain telescope or C-8

Celestron 4-inch achromatic refractor

or C-102 Orion XT-10 Newtonian Reflector

Astroscan Binoculars

(7)

Instructional Value of the Individual Messier Objects

Table 1

Instructional Values of Messier Objects

(8)

(9)

(10)

(11)

(12)

(13)

(14)

(15)

(16)

(17)

(18)

(19)

(20)

(21)

(22)

(23)

(24)

(25)

CRAB NEBULA

Catalogue Designations:

M1

NGC 1952

It is a supernova remnant and pulsar wind nebula in the

constellation of Taurus. It is

part of the Perseus Arm of the

Milky Way Galaxy.

(26)

ANDROMEDA GALAXY

Catalogue Designations:

M31 NGC 224

It is a large spiral galaxy, very similar to Milky Way galaxy. It is heading our way and on a collision with the Milky Way.

Image credit: NASA/JPL-Caltech/ESA/Harvard-Smithsonian CfA

(27)

GLOBULAR CLUSTER

Catalogue Designations:

M4

NGC 6121

It contains over 10,000 stars. It is one of the nearest globular clusters to our solar system.

Image credit: NASA/ESA Hubble Space Telescope

(28)

RING NEBULA

Catalogue Designations:

M57 NGC 6720

It is the most famous celestial band.

Ionized oxygen atoms produce the greenish glow and the red emission is from the ionized hydrogen.

Image credit: M57 ring nebula -HST-Subaru-LLgendler.jpg

(29)

BODE’S GALAXY

Catalogue Designations:

M81 NGC 3031

It is a grand design spiral galaxy because of its elegant arms curl all the way down into its center. It is one of the

brightest galaxies that can be seen from Earth through

telescopes.

Image credit: NASA/JPL-Caltech/ESA/Harvard-Smithsonian CfA

(30)

CIGAR GALAXY

Catalogue Designations:

M82 NGC 3034

It is an Irregular galaxy. It has a red-glowing outwardly expanding gas caused by emerging particle winds of many stars.

Image credit: http://apod.nasa.gov

(31)

VIRGO A

Catalogue Designations:

M87 NGC 4486

The jet is created by energetic gas

swirling around a massive black hole at the galaxy’s center.

Image credit: http://apod.nasa.gov

(32)

Definition of Terms

• Active Galactic Nucleus. The central galactic region of galaxy in which considerable energy is generated by processes other than those operating in normal stars.

Oxford Dictionary of Astronomy

• Barred spiral galaxy. A spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in approximately two-thirds of all spiral galaxies. en.wikipedia.org/wiki/Barred_spiral_galaxy

• Black hole. According to the general theory of relativity, a black hole is a region of space from which nothing, including light, can escape. It is the result of the denting of spacetime caused by a very compact mass. Around a black hole there is an undetectable surface which marks the point of no return, called an event horizon. It is called

"black" because it absorbs all the light that hits it, reflecting nothing, just like a perfect black body in

thermodynamics. Under the theory of quantum mechanics black holes possess a temperature and emit Hawking radiation through slow dissipation by anti-protons. http://simple.wikipedia.org/wiki/Black_hole

• Blue stragglers. Blue stragglers (BSS) are main sequence stars in open or globular clusters that are more luminous and bluer than stars at the main sequence turn-off point for the cluster…In a cluster, stars all formed at

approximately the same time, and thus in an H–R diagram for a cluster, all stars should lie along a clearly defined curve set by the age of the cluster, with the positions of individual stars on that curve determined solely by their initial mass. With masses two to three times that of the rest of the main sequence cluster stars, blue stragglers seem to be exceptions to this rule. http://en.wikipedia.org/wiki/Blue_straggler

• Cataclysmic variable. A variable star that exhibits sudden outbursts generally arising either from the release of gravitational energy through accretion or from thermonuclear processes.

(33)

• Dark matter. In astronomy and cosmology, dark matter is a type of matter hypothesized to account for a large part of the total mass in the universe. Dark matter cannot be seen directly with telescopes; evidently it neither emits nor absorbs light or other electromagnetic radiation at any significant level. Instead, its existence and properties are inferred from its gravitational effects on visible matter, radiation, and the large scale structure of the universe. Dark matter is estimated to constitute 84% of the matter in the universe and 23% of the mass- energy. http://en.wikipedia.org/wiki/Dark_Matter

• Dwarf elliptical galaxy. Elliptical galaxies that are much smaller than others. They are classified as dE, and are quite common in galaxy groups and cluster, and are usually companions to other galaxies.

en.wikipedia.org/wiki/Dwarf_elliptical_galaxy

• Globular cluster. A roughly spherical group of old stars in the halo of a galaxy. Oxford Dictionary of Astronomy

• Elliptical galaxy. A type of galaxy with a smooth, featureless circular or elliptical appearance, no spiral arms, and little or no interstellar gas or dust.

• Herbig-Haro objects. A small nebula with an emission-line spectrum, found in regions of star formation.

• lenticular galaxy. A type of galaxy with a definite disk of stars and a central bulge, but showing no sign of spiral arms and little or no interstellar material.

• Open cluster. A comparatively young, irregularly shaped group of stars, often numbering up to several hundred, and held together by mutual gravitation; usually found along the central plane of the Milky Way and other galaxies. http://dictionary.reference.com/browse/open+cluster

(34)

• Planetary nebula. A gaseous shell thrown off by a dying star before the star settles down to become a degenerate white dwarf.

McGraw Hill Science and Technology Encyclopedia

• Seyfert galaxy. A type of galaxy with a small, bright nucleus.

Oxford Dictionary of Astronomy

• Supernova. A supernova (abbreviated SN, plural SNe after

supernovae) is a stellar explosion that is more energetic than a nova. Supernovae are extremely luminous and cause a burst of

radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months. During this short interval a supernova can radiate as much energy as the Sun is expected to emit over its entire life span.

http://en.wikipedia.org/wiki/Supernova

(35)

Conclusions and Recommendations

• The teaching of Astronomy can be accomplished better with field

observations with the use of telescopes. Pictures of astronomical objects, especially if taken with the Hubble Space Telescope are stunning, but

there is really no substitute to seeing the objects themselves through telescopes, no matter how featureless the objects may appear. Students like to do field observing. Looking through a telescope is an exciting

experience to them.

• Teaching Astronomy through the Messier Objects leads to better

understanding of the concepts and principles. Further, young initiates to Astronomy find a sense of accomplishment in gathering their observations of the Messier Objects, as this is arguably the most famous listing of all.

Students should be encouraged to keep a journal of their observations, and to have a Messier checklist. Students should be taught the

fundamentals of sketching what they see in the eyepiece of a telescope,

and to keep a record of their impressions.

(36)

• Teachers should themselves familiarize themselves with the night sky, and to be able to use star maps to locate objects in the sky. In this way, the use of manually-operated telescopes would be easier.