an introduction to cosmic mining james webb space...
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AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
A ‘RESEARCH IN SCHOOLS – AT HOME’ PROJECT
www.researchinschools.org [email protected]
This project has been developed by the Institute for Research in Schools and the Science and Technology
Facilities Council.
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AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
CONTENTS
Privacy, GDPR and Safeguarding Statement PG 4
Curriculum Links PG 5
Introduction PG 6
The Life Cycle of Starts and Stellar Evolution PG 8
Forming Stars PG 9
Stars PG 9
Evolved Stars PG 10
Checkpoint 1 PG 11
Exploring the Universe PG 12
Infrared Astronomy PG 13
Checkpoint 2 PG 14
James Webb Space Telescope PG 14
Checkpoint 3 PG 15
Photometry and Spectroscopy PG 17
Introduction to Spectra PG 19
Checkpoint 4 PG 22
Identifying Spectra PG 24
Forming Stars PG 25
Evolved Stars PG 26
Planetary Nebulae PG 27
Ordinary Stars PG 28
Unusual Objects (other) PG 29
Noise PG 30
Identification Key PG 30
Activity 1 PG 32
Activity 2 PG 35
Answer Booklet PG 38
PG 2
NASA engineer Ernie Wright looks on as the first six flight ready James Webb Space
Telescope's primary mirror segments are prepped to begin final cryogenic testing at
NASA's Marshall Space Flight Center
Image Credit: NASA/MSFC/David Higginbotham
AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
PRIVACY, GDPR & SAFEGUARDING
The following data will be collected by the Institute for Research in Schools (IRIS) when
students submit their completed activity:
• Student Name (First Name and Surname)
• Student Email
• Year Group
• School Name
• Teacher Email
The data will be used to generate a participation certificate and provide students with
feedback. This will be emailed directly to students along with a link to a participant survey.
Student names and email addresses will be deleted by IRIS within 2 weeks of us receiving a
student’s submission.
Information on the year group of students along with which schools have participated in this
project will be recorded and used with the participant survey results to evaluate the impact
and effectiveness of the project. This information may be shared with funders and other
interested parties. No specific student data is shared.
As part of IRIS’ safeguarding procedures, when emailing students directly, a teacher must
always be copied in. The teachers email address provided during the submission of a
student’s work will be deleted by IRIS within 2 weeks of the submission. Students should use
their school email accounts when emailing IRIS.
Teachers can, if they wish, provide a school email address for the purposes of IRIS
contacting them in future about the work of IRIS. Their data will not be shared with any third
parties.
If you have any questions regarding privacy, GDPR or safeguarding please visit our website
(www.researchinschools.org) or email [email protected].
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AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
CURRICULUM LINKS
ENGLAND AND WALES
• Electromagnetic Waves and Light (GCSE Physics, GCSE Double Science)
• Life Cycle of a Star (GCSE Physics)
• Spectroscopy (A Level Physics)
• Astrophysics and Space –Telescopes, Star Classification and Cosmology (A Level
Physics)
• Waves and Particle Nature of Light (A Level Physics)
SCOTLAND
• National 5 Physics: Space – Cosmology
• Higher Physics: Our Dynamic Universe – The Expanding Universe, Particles and
Waves – Interference and Diffraction, Spectra
• Advanced Higher Physics: Stellar Physics
Three engineers from the European Space Agency wearing blue hoods are investigating the Mid-Infrared Instrument (MIRI) that recently arrived at NASA Goddard’s clean room from the U.K. The MIRI sees light in the mid-infrared region of the electromagnetic spectrum.
Image Credit: NASA/Chris Gunn
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AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
INTRODUCTION
An artist impression of the James Webb Space Telescope
Image Credit: NASA/Northrop Grumman
The James Webb Space Telescope (JWST or Webb) is scheduled for launch in 2021 and
will be the world’s premier observational telescope of the next decade. It will study every
phase in the history of our Universe, ranging from the first glows after the Big Bang to the
formation of solar systems capable of supporting life on planets like Earth.
Webb has been designed to help us understand more about how our Universe formed and
evolved. We know that, at a chemical level, most of the materials around us were formed
by stars living, dying and colliding with each other. There are still many open questions as
to how these materials are made and distributed throughout galaxies like our Milky Way.
One way to learn more about this is to study cosmic dust and astronomers hope to use
Webb to do this.
Once Webb is launched and active, astronomers from around the world will be using its
instruments to explore our galaxy and beyond. As you can imagine, time on the telescope
is in huge demand and is extremely valuable. Before scientists are chosen to use the
telescope, they must justify why they want to have telescope time and what they will be
doing with that time – they can’t simply point it out into space and hope for the best!
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The James Webb Cosmic Mining
project run by the Institute for
Research in Schools (IRIS) and
funded by the Science and
Technology Facilities Council
(STFC), helps astronomers identify
potential targets for Webb. Students
and schools working on the project
analyse observations made by the
Spitzer Space Telescope and look
for interesting, unexplored ‘space
gems’ worthy of further study with
Webb. This is cutting-edge, high-
level scientific research that will
contribute to our understanding of
the Universe around us.
‘An Introduction to Cosmic Mining’ –
will provide you with an introduction
to the process by which
astronomers learn more about stars
from the light they emit. This project
will allow you to develop your
understanding of key scientific
knowledge while applying it to real
life science!
If you would like to learn more about
the JWST, visit these websites:
• https://www.jwst.org.uk/
• https://www.jwst.nasa.gov/
• https://webbtelescope.org/
The most powerful and complex space telescope ever created by humankind achieved
its final form as a fully assembled observatory in August 2019.
Image Credit: NASA//Chris Gunn
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AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
THE LIFE CYCLE OF STARS & STELLAR EVOLUTION
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Forming Stars
Stars form from a cloud of dust and gas (mainly hydrogen) called a nebula; they are often
called stellar nurseries! The dust and gas spirals and collapses under gravity while heating
up, this process forms a protostar.
Gravitational attraction causes the size and density of the protostar to increase which forms
a pre-main sequence star. As particles in a pre-main sequence star collide with each other
more and more, the temperature starts to rise. At this point, it is not yet hot enough to drive
nuclear fusion reactions turning hydrogen to helium at the stellar core. When the
temperature gets hot enough nuclear fusion is established which releases a huge amount
of energy keeping the newly formed star hot. Pre-main sequence stars are often
surrounded by a protoplanetary disc (dense gas and dust) which may go on to form planets
and other objects that orbit the star.
For more information on nuclear fusion, follow this link:
https://www.bbc.co.uk/bitesize/guides/zx86y4j
Stars
Once hot and dense enough to sustain stable nuclear fusion of hydrogen into helium, a
star has been formed. A star’s stability is created through a balance of outward pressure
from nuclear fusion and gravity pulling inwards.
Once a star has achieved this stability it is called
a main sequence star. Stars spend most of their
lives in this phase. The length of the main
sequence phase depends on the stars mass, and
is typically several billion years. Our solar
system’s star, the Sun, is a stable main sequence
star.
After a very long period of time, the hydrogen fuel in the core of the star will start to run out.
This causes the fusion of hydrogen to stop and the inner regions of the star to contract and
heat further. The increased temperature triggers helium fusion and the star enters its post-
main sequence phase.
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Evolved Stars
When the hydrogen fuel in the stellar core runs out, fusion stops and the inner regions of
the star begin to contract and heat up again. Several processes can occur in an evolved star
to produce heavier elements and disperse them through space.
Smaller stars, similar to the size of our Sun, will expand and turn into a red giant. Hydrogen
fusion can take place in a shell around the core and helium in the core can eventually fuse to
create oxygen and carbon. These internal changes cause the star to expand and become a
very luminous star with a cool surface. This is why it looks red.
As the helium fuel in the core is exhausted, a number of unstable layers are formed from
different types of elements fusing together. This causes the star to become unstable and it
pulses regularly.
A star ends its life when it can no longer sustain fusion reactions and ejects its outer layers of
dust and gas to form a colourful planetary nebula. The remaining core of the star is left
behind and contracts to form a very hot and dense, planet-sized object called a white dwarf.
The Sunshield on the James Webb Space Telescope is the largest part of the observatory
being around the same length as a tennis court. It is made from five layers of thin membrane.
Image Credit: NASA//Chris Gunn
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Over time the white dwarf cools down, as a result it releases less energy (light and heat).
When it stops releasing a significant amount of energy it turns into a black dwarf and is no
longer visible. Although many GCSE and A-level courses refer to black dwarfs, the existence
of these stellar objects are only theoretical.
Large stars, with significantly higher masses than our Sun, will turn into red super giants
once they run out of hydrogen fuel in their core. Red super giants are formed as they are
able to fuse heavier elements up to Iron in their core. This causes the star to expand and
contract several times. Red super giants become unstable when they run out of elements
which can fuse together and their lives end in a supernova explosion. This event destroys
the star and launches materials into space. Many of the heavier elements, such as
radioactive uranium, are created in these violent events.
After going supernova, large stars leave behind incredibly dense, city-sized objects known as
neutron stars. The most massive stars do not turn into neutron stars but instead become
black holes, objects so dense that even light cannot escape their grasp.
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AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
EXPLORING THE UNIVERSE
Cosmic dust, also called extra-terrestrial dust or space dust, is dust (think tiny particles of
sand or soot) which exists in outer space. Cosmic dust is a great tracer of the chemical
evolution of galaxies. By studying the amount and different types of elements in dust we can
learn how the materials around us were created over the history of the Universe. But how do
we study dust in space? We do it by examining how much light a star gives off at different
wavelengths and looking for tell-tale features which are hallmarks of light emitted by dust.
In this artist's rendering of NASA's Spitzer Space Telescope in space, the background is shown in infrared light Image Credit: NASA/JPL-Caltech
The Spitzer Space Telescope was launched by Nasa in 2003 from Cape Canaveral in
Florida, USA. It continued to operate until it was retired on 30th January 2020. The goal of
Spitzer was to provide a unique, infrared view of the Universe and allow us to peer into
regions of space that are hidden from optical (light) telescopes. Spitzer observed over ten
thousand points of sources (a single identifiable localised source of light), that is a huge
amount of data! Much of the data has not yet been analysed or looked at by astronomers,
and students completing the full IRIS JWST project will, in many cases, be the first
individuals to look at that data in order to find targets for the JWST.
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Infrared Astronomy
Infrared is a type of electromagnetic (EM) wave. There are seven types of electromagnetic
wave:
• Radio
• Microwave
• Infrared
• Visible Light
• Ultraviolet
• X-rays
• Gamma Rays
These electromagnetic waves form a continuous spectrum of different wavelengths called the
Electromagnetic Spectrum:
Before moving on, you should ensure that you are comfortable with the features and nature of
waves. For more information on waves please follow this link:
https://www.bbc.co.uk/bitesize/guides/zgf97p3
Electromagnetic waves all travel at the same speed through a vacuum (e.g. space) – 3 x 108
m/s, that is 300 000 000 m/s or around 671 000 000 mph.
Infrared light is of interest to scientists because it can reveal information
about:
• Cool objects in the universe.
• The oldest stars and galaxies.
• The atoms and molecules found in dusty regions of space,
for example star forming regions.PG 13
Telescopes on Earth are used to observe targets in the infrared range but not all infrared light
makes it to the surface of Earth. Some are absorbed by water vapour in the Earth’s
atmosphere, meaning that observations from space are required in order to view the full range
of infrared wavelengths.
Areas containing large amounts of gas and dust absorb visible wavelengths. Infrared light has
longer wavelengths and it is able to pass through this gas and dust without being absorbed.
This allows astronomers to find out more about dusty areas such as star forming regions
James Webb Space Telescope
Please Watch: Webb Space Telescope - a video overview by NASA:
https://youtu.be/aC6BGIAvccE
Webb will view the Universe at infrared wavelengths. It is the largest and most complicated
telescope design ever built for use in space. It will sit at L2, the second Lagrange point, a place
where the gravitational pull of the Sun and Earth balance.
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There are three key elements to the JWST: sunshield, six-meter mirror and instruments.
• The JWST must run at very cold temperatures in order to see the light from the coldest
and faintest targets. A sunshield is used to keep the telescope and instruments cool so
that they are not overwhelmed by light and heat from the Sun.
• The primary mirror (the main collector of light) is made up of eighteen hexagons. It
bounces light to a secondary mirror which reflects it onto the scientific instruments.
• Webb has four instruments providing a wide range of cameras, spectrographs and other
optical devices to collect and analyse light depending on the scientific goal. For example,
some instruments have coronagraphs. These block the light from a bright object so that
nearby faint objects can be seen. These will be used to study exoplanets (planets outside
the Solar System).
An artist impression of the James Webb Space Telescope
Image Credit: NASA/Northrop Grumman
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AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
PEOPLEPeople from across the UK are playing an active
role in the Webb story. Meet some of them and
explore an interactive map to see what’s been
happening near you by visiting:
www.jwst.org.uk/people
AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
PHOTOMETRY AND SPECTROSCOPYPhotometry is the measure of how much light an object is giving off at specific wavelength
ranges.
White light is made up of all wavelengths of
the electromagnetic spectrum in the visible
part of the spectrum. White light can be
split into its composite wavelengths using a
prism. The resulting continuous spectrum
of wavelengths appears in the visible range
to our eyes as a rainbow. The spectrum
continues beyond the visible into longer
and shorter wavelengths.
This splitting of light can be used in many situations to understand more about the
source of that light. For example, by studying light from a star that has passed through a
cloud of gas it is possible to identify atoms and molecules within the cloud.
Different atoms and molecules can absorb energy from incoming light, for example when
light passes through a cloud of gas. Evidence of this can be seen through the presence
of black lines on a spectrum – these are known as absorption lines.
Due to the movement of electrons inside atoms and molecules, energy can also be
emitted as light. This results in emission lines being produced.
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Each type of atom or molecule emits and absorbs a unique set of wavelengths which can act
like a distinctive fingerprint for that specific substance. When scientists look at a type of
graph called a spectrum and see a specific set of wavelengths, they know exactly which
atom or molecule created it.
Ball Aerospace's Jake Lewis is reflected in one of the mirrors on a James Webb Space Telescope Array that was in the X-ray and
Cryogenic Facility for Testing.Image Credit:
NASA/MSFC/David Higginbotham/Emmett Given
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AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
INTRODUCTION TO SPECTRA
The spectrum above has been produced by instruments on Spitzer. The instruments
recorded infrared waves coming from an unknown object in space (a stellar object).
Although it may look complicated, spectra are very simple to interpret and can tell us a lot
about the object they came from.
Each observation made by Spitzer is unique and therefore each spectrum has a unique
identifier called an AOR key; you can see this at the top of the image above
The y-axis tells us how much light there is (Flux Density), whilst the x-axis tells us the
wavelength of the light. In infrared astronomy, the unit of wavelength used is
micrometres or microns (10-6m).
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As we explored in the previous sections, spectra can have emission or absorption lines,
the wavelengths of which can be used to identify elements or molecules. You can see on
the annotated spectrum above that there are clear emission lines that do not follow the
overall trend in the continuum (purple line). Some emission lines are narrow, others are
broad.
Atomic emission lines appear narrow and will be centred exactly on the expected
wavelength. On the example spectrum above, you can see that there is a narrow
emission line at around 15.5 microns. This is a typical identifying feature of Neon [Ne III].
Broad emission lines represent the average around which the line is centred. In the
example provided, the broad emission line peaks at around 11.2 to 11.3 microns.
Emission and absorption lines are important to help us to identify specific features of
stellar objects, however we must also be able to describe the gradient and general trend
in curve of the spectrum in order to identify the type stellar object.
Example A
In this spectrum the gradient
increases and continues to
increase past 30 microns.
Although there is some noise
past 30 microns, it is clear to
see that the overall trend of
the gradient increases from
left to right or with increasing
wavelength.
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Example B
In this example there is a
rising spectrum which flattens
out and dips after 30 microns.
Example C
In this spectrum, the gradient
is decreasing and generally
smooth with very few emission
or absorption features.
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Engineer Erin Wilson prepares for the environmental testing of special optical equipment. These tests will verify the alignment of the actual flight
instruments that will fly aboard the James Webb Space Telescope.Image Credit:
NASA/Chris Gunn
AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
IDENTIFYING SPECTRAThe main activities within this project requires you to identify stellar objects based on their
spectrum. There are 7 different stellar objects that you can choose from:
• Evolved star
• Forming star
• Star (main sequence)
• Planetary nebula
• Galaxy
• Unusual (Other)
• Noise
Over the next few pages, you will be able to explore each type of object and the typical
spectra they generate.
This Hubble photo is of a small portion of one of the largest seen star-birth regions in the galaxy, the Carina Nebula. Towers of cool hydrogen laced with dust rise from the wall of the nebula. Image Credit: NASA, ESA, and M. Livio and the Hubble 20th
Anniversary Team (STScI)
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Forming Stars
These are spectra of forming stars.
In each of these spectra the gradient of the line spectrum continues to increase above 30 microns.
Optical image of young stars in the Orion nebula surrounded by protoplanetary disk.Image Credit: C.R. O'Dell/Rice University NASA/ESA)
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Evolved Stars
These are spectra of evolved stars.
The main features of these type of
spectra are:
• Decreasing spectrum.
• There is sometimes a dip in the
spectrum at 6 and 8 microns.
This differentiates an evolved
star from an ordinary star.
• Broad emission or absorption
features due to molecules.
A cluster of evolved stars called Red Super Giants.Image Credit: NASA/NSF/2MASS/UMass/IPAC-Caltech/D. Figer (Space Telescope ScienceInstitute/Rochester Institute of Technology).
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Planetary Nebulae
These are spectra of evolved planetary nebulae.
The main features of these type
of spectra are:
• Rising spectrum which
flattens or dips after 30
microns.
• They have broad emission
features and narrow
emission features.
Infrared image of a planetary nebula called the Helix Nebula.Image Credit: NASA/JPL-Cal tech
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Ordinary Stars
These are spectra of ordinary stars.
Unlike the spectra of evolved stars, these are much smoother without large emission or absorption features. Most of the variation seen in the smooth continuum is due to noise.
The Sun is halfway through its lifetime.Image Credit:
SOHO - EIT Consortium/ESA/NASA
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Unusual Objects (other)
These are spectra of more unusual objects. Compare these to the other groupings you have looked at. Do they fit into any of them?
These will be classified as “Other” when it comes to the analysis.
1. The first spectrum is of a R Coronae Borealis variable star. The light given out by this star changes over time.
2. The second spectrum is a Blue Supergiant star. These are very large and bright stars that have relatively short lifespans. These stars that through their Hydrogen very quickly.
This is an important grouping. You will come across quite a few objects that will be classified
as “other”. These are often some of the most scientifically interesting objects.
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Noise
The grey areas on the spectrum are ‘error bars’. The trace (line) going through the middle is
the most likely value but the true value can lie anywhere within the shaded region. The
‘noise’ in the data reflects the fact that the signal is weak relative to the background level. If
there is a lot of noise we cannot accurately identify the stellar object.
Identification Key
In order to assist you in identifying stellar objects the key below can be used.
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The wings and telescope structure of the James Webb Space Telescope. The wings and structure are essential because they make up the telescope's carbon fibre framework which will hold all 18 of the telescope's mirrors and the tower for the primary mirror.Image Credit: NASA/Chris Gunn
AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
ACTIVITY 1Over the next two activities you will be focusing on classifying spectra produced from
data collected by the Spitzer Space Telescope. These spectra are from a range of
different objects including planetary nebulae, forming stars and evolved stars.
The spectra you will be examining are available to download online from the CASSIS
database (https://cassis.sirtf.com/). This holds over ten thousand spectra. These
observations were taken at the request of many different astronomers. Although the
database holds information about each object, the classification of each spectrum has not
been done on a large scale and in some cases you may be the first person to look at the
results.
Accessing CASSIS data
Using a web browser, open the following page: https://cassis.sirtf.com/
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Select “Proceed to CASSIS Query for IRS spectra”.
For activity 1, you will be asked to classify 9 objects based on their spectrum. For each
object you will be supplied with the “AORKey”.
Enter the AOR Key into the field and select “Search for Spitzer Spectra”, this is shown
below.
Once you have submitted the AOR Key you will be taken to a new web page. Scroll
down until it you see the spectrum.
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In some rare instances, you may find that there are several spectra available. As well as
an AOR Key you will also be provided with a ‘Pointing” number.
Where several spectra are available, look for the AOR Key which has the matching
pointing number as shown below.
It is now time to classify your first objects. Using the guide above and information in the booklet
have a go at classifying the following stellar objects. Once you have completed this activity you
can check your classifications using the answer section at the back of this booklet.
Object AORkey Pointing Number
1 27533824 0
2 4954624 0
3 10667008 0
4 6017792 0
5 10655488 0
6 27520256 0
7 4953088 0
8 12928001 0
9 17409536 0
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AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
ACTIVITY 2
You are now ready to complete the main task!
When you received this booklet, you should have also received an excel spreadsheet
called “Activity 2 IRIS Webb at Home”. If you have not received this, please email
[email protected] to request a copy.
Open the spreadsheet to start and follow the instructions below.
The spreadsheet lists 30 unknown objects. Using the CASSIS database, attempt to
classify each object and record your answers in the ‘Classification’ column by selecting
your answer from the drop-down options.
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AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
ACTIVITY 2Once you have attempted to classify all 30 objects, please email your completed
spreadsheet to [email protected]. A member of our team will review your
answers and send you a participation certificate along with feedback on how you did. If,
after receiving your certificate, you would like another go you may submit another set of
answers.
Please ensure that you complete all the boxes at the top of the excel spreadsheet. When
submitting your answers by email you should use your school email account. Please
attach your completed excel file to the email, do not attach a link from your school cloud
as we will not be able to access the file. For more information about privacy, GDPR and
safeguarding please see page 4.
This project introduces you to and gives you a preview of the ‘James Webb Space
Telescope Cosmic Mining’ project. If you would like more information on this project
please go to www.researchinschools.org. If you would like to participate in the full project,
your school will need to register as an IRIS school. Information on how to sign up can be
found on our website.
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AN INTRODUCTION TO COSMIC MININGJAMES WEBB SPACE TELESCOPE
ANSWER BOOKLETCheckpoint 1
A) A nebula is made from dust and gas (mainly hydrogen).B) Pre-main sequence stars are often surrounded by a protoplanetary disc (dense gas
and dust) which may go on to form planets and other objects that orbit the star.C) A main sequence star.D) A star’s stability is created through a balance of outward pressure from nuclear fusion
and gravity pulling inwards.E) HeliumF) Large stars will turn into super red giants and eventually go supernova. After going
supernova white dwarfs will form and cool down to turn into black dwarfs. Very large stars will create a black hole.
G) A red giant looks red because the surface has cooled down.
CHALLENGE) As stars form, they often have a protoplanetary disc made from dense gas and dust. Over time, the gas and dust spiral together due to gravitational forces and create planets that surround the newly formed star.
Checkpoint 2
A) Cosmic dust, also called extra-terrestrial dust or space dust, is dust which exists in outer space.
B) To provide a unique, infrared view of the universe and allow us to peer into regions of space that are hidden from optical (light) telescopes.
C) Radio, Microwave, Infrared, Visible Light, Ultraviolet, X-rays and Gamma rays.D) Radio waves have the longest wavelength at 10-1m while Gamma rays have the
shortest wavelength at 10-15m. E) It allows astronomers to observe: Cool objects in the universe OR The oldest stars and
galaxies OR The atoms and molecules found in dusty regions of space, for example star forming regions.
CHALLENGE) Areas containing large amounts of gas and dust absorb visible wavelengths meaning they cannot pass through and reach the telescope or earth.
Checkpoint 3
A) Where the gravitational pull of the Sun and Earth are balanced.B) A sunshield is used to keep the telescope and instruments cool.C) If the instruments and telescope warm up, they will emit infrared radiation that would
interfere with detecting infrared waves from deep space.D) Planets outside the Solar System.
Checkpoint 4
A) Overall, there is a decreasing spectrum. There is a dip in the spectrum at around 6 to 8 microns. Beyond 15 microns the spectrum begins to fall more gradually.
B) The spectrum rises and then dips after 30 microns. There is a narrow emission line at around 15.5 microns and a broad emission line which peaks at around 11.3 microns.
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Activity 1 Answers
Object AORkey Pointing Number Classification
1 27533824 0 Forming Star
2 4954624 0 Planetary Nebula
3 10667008 0 Evolved Star
4 6017792 0 Ordinary Star
5 10655488 0 Other (Unknown)
6 27520256 0 Forming Star
7 4953088 0 Planetary Nebula
8 12928001 0 Evolved Star
9 17409536 0 Evolved Star
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