I teach an Introductory Astronomy course at Bryant University – a small university with a total undergraduate enrollment of a little over 3,000 students.  Although Bryant University has a College of Arts & Sciences (which included only one ‘Department of Science’,) and now a School of Health and Behavioral Sciences, it is well known for its College of Business.  This is where most of my students come from.  In my class, I try to not only teach them all about our amazing universe, but also ‘how’ we know all of this.  Sometimes the ‘how’ is mathematical and sometimes it isn’t.  I’ve also run into semesters where we get so far behind (a semester when we seemed to have a class-canceling snowstorm every week or many tech issues during COVID), that covering the entire syllabus was very challenging.  So, over the years of teaching, I have developed a number of in-class group activities (“In-class Homework”) that help in my mission.

When I started these activities, some of them were begun in class, but had an ‘out of the class’ component.  Unfortunately, group dynamics don’t always work well, and a number of students had trouble meeting with their group outside of class, resulting in reduced grades.  These were in the days before zoom, so to solve this, all activities are now only in the classroom.  Fortunately, my class meets for 1¼ hours, so there is time for the activities and then (sometimes) time left over to return to the class lecture.  Mathematically speaking, I am dealing with a math-challenged group.  Ask them to calculate, for example interest, they can do it in their sleep, but the minute I ask them to calculate circular velocity, they look at me like I have two heads.  These are smart students, but many of them tell me “I don’t understand science.”  Hence my challenge!

I cover Kepler’s Laws and Newton’s Laws early in the semester.  To show the importance of math in astronomy and spaceflight, I developed a multi-part group activity where the premise is that the group is the first manned mission to Mars.  Think The Martian but with no infrastructure on the planet.  In part 1, I have the students calculate the spacecraft’s orbital period and semi-major axis using Kepler’s Laws, as well as the round-trip travel time needed for a simple conversation between astronauts on Mars and mission control on Earth.  In part 2, they calculate first the escape speed needed to leave Earth’s orbit, then the speed of Mars in its orbit.  The students work in groups, but each student submits their calculations for grading.  I do walk around the room to help the students as needed (and often a lot is needed, including how to use the calculator to complete the calculations.)  At the end of the ‘part 2’ activity I show them the clip from The Martian where Rich Purnell explains his proposal to the group (my favorite scene of the movie – ‘the math checks out’.) 

I also have several non-mathematical activities that I’ve used, including one that helps the students to learn about the “how we know what we know” and one that is perfect for the “uh-oh I’m out of time, what do I do” moment near the end of the semester.  I look forward to discussing my activities with you in an upcoming coffee break!  I would love to hear your thoughts about class activities as well.  The coffee break will be held Thursday, December 1, 2022, at 3pm EST.  You can sign up to join us here.  If you are reading this after the fact, you can get a link to the recording by reaching out to [email protected].  Don’t forget to bring your favorite afternoon beverage and I look forward to seeing you on December 1st!

-Sandi Brenner, Bryant University

https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-reveals-cosmic-cliffs-glittering-landscape-of-star-birth

The Carina Nebula is a nearby (about 7,600 ly away) star-forming region, and this image captures just a segment of it. Above the image (out of frame) are a number of hot, young stars, producing outflows that are blowing around the dust and gas, carving out a cavity. This image captures the edge of that cavity, at the boundary between the thick dust and the partially-evacuated region.

I particularly like to point out “fingers” in the dust, which so nicely show which way the stellar winds are blowing. These fingers are dust shadows behind denser regions from which stars can form.

NBC News put together a particularly nice comparison of this image with the same image taken by HST (https://www.nbcnews.com/data-graphics/compare-photos-nasas-james-webb-space-telescope-hubble-space-telescope-rcna37875). By moving the slider back and forth, you can see how the infrared observatory sees through the dust to the underlying (newly-forming!) stars. More detail is evident in the JWST image as well, due to Webb’s increased aperture. It’s a beautiful example of how observations from telescopes operating at different wavelengths can complement each other. While the registration of the two images is not exactly perfect, it’s close enough to compare subtle details between the two images. One not-so-subtle detail jumps out that could be used to spark class discussion: near the center of the JWST image is a bright yellow star with prominent diffraction spikes. Slide the slider across to see it in the HST image, and you’ll know if your students are paying attention or not…

Supporting material in the texts and online: This image provides a great opportunity to talk to students about why astronomers use telescopes that observe at different wavelengths to explore different parts of the universe. You might reference this image in the chapters on Telescopes, Star Formation, or the Interstellar Medium. Other connected material appears in:

Process of Science Assignment: Interpreting Radiation through ISM

Astronomy in Action Video: Emission and Absorption

Learning Astronomy by Doing Astronomy Workbook, Activity 22: The Stuff Between the Stars will help students interpret what they see in this image, while Activity 7: Light and Spectra will help them understand the pairing of telescope and target, and why this region is a good target for JWST

https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-captures-dying-star-s-final-performance-in-fine-detail

The Southern Ring Nebula is a striking example of a bipolar planetary nebula, seen very nearly along the axis. Planetary nebulae result from the death of low-mass stars, and their shaping mechanisms have long been somewhat mysterious. In this image from JWST, a binary system is visible at the center of the nebula, which may provide the shaping mechanism for this object. Comparison with the HST image show that the binary star at the center was invisible before JWST took this image.

Most of the carbon in their bodies once passed through a planetary nebula like this one, as the carbon was lost from the star that fused it. Later, that carbon wound up in the cloud from which our solar system formed, so these objects have a personal relevance to our own existence.

The colors in the JWST image are not “true-color”, and this is perhaps a good image to show to initiate that conversation--why do astronomers make the color choices they do, and do the colors actually mean anything at all? (Sometimes it’s just because the person making the image liked those colors…but yes, the colors still have meaning.)

Supporting material in the texts and online: This image provides a great opportunity to talk to students about why astronomers use telescopes that observe at different wavelengths to explore different parts of the universe. You might reference this image in the chapters on Telescopes, or the Interstellar Medium. Other connected material appears in:

Exploration: Evolution of Low-Mass Stars

Process of Science Assignment: Low mass life cycle

Interactive Simulations: H-R Diagram

Astrotours: H-R Diagram

Learning Astronomy by Doing Astronomy Workbook, Activity 21: Understanding the Evolution of the Sun explores the life and death of low-mass stars.

https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-reveals-steamy-atmosphere-of-distant-planet-in-detail

I freely admit that my mind is blown any time anyone presents any data that shows anything definite about the atmospheres of exoplanets. I (wrongly) predicted that we would not see this in my lifetime, and I could not be more delighted to be wrong.

The first JWST exoplanet spectrum came in the original release of five images, and identified water in the atmosphere of WASP-96 b. This is a hot gas giant orbiting a Sun-like star more than 1,000 ly away. The spectrum is a transmission spectrum: the planet was observed as it transited the star, and then the spectrum was compared to that of the star when the planet is not in view. The spectrum has a wide range of wavelengths, and multiple water lines are present across the full spectrum. I see other narrower lines there as well that I’m certain are being investigated further.

But already, we have more! In August, a similar transmission spectrum for WASP-39 b was released, (https://www.nasa.gov/feature/goddard/2022/nasa-s-webb-detects-carbon-dioxide-in-exoplanet-atmosphere) showing a clear detection of carbon dioxide in the atmosphere of that hot gas giant.

All that said, it’s a bit of a heavy lift to help students understand how exciting a graph can be!  They’ll need you to help them understand why they should be astonished that we can determine the composition of the atmosphere of a planet (even a Jupiter-sized one) from 1,000 light years away.

Supporting material in the texts and online: This image ties in to a deep fascination about life in the universe---if we are all honest about it, we are anxiously awaiting the first detection of O₂. You might reference this image in the chapters on the Formation of Stars and Planets, the Giant Planets, Exoplanets or Life in the Universe.

Exploration: Exploring Exoplanets

Process of Science Assignment: Light and Spectroscopy

Interactive Simulations: Planetary Orbits Simulator and Habitable Zone

Astrotours: Atmospheres: Formation and Escape

Astronomy in Action videos: Emission and Absorption

Learning Astronomy by Doing Astronomy Workbook, Activity 6: Extraterrestrial Tourism explores the relationship between observations and properties of planets; Activity 35: Finding Habitable Worlds beyond Earth will help students understand why we are interested in the orbital properties of planets.

https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-sheds-light-on-galaxy-evolution-black-holes

Stephan’s Quintet is most famous for its appearance in It’s a Wonderful Life, and I really enjoy privately mulling over the absolutely astonishing improvements in imaging, physical understanding, and even humility that have occurred between the time when the image appeared in the film and the time when this JWST image was taken. However, I am not so foolish as to think that students yet enjoy that type of perspective. So, I share it with you but stick to the astronomy with my students!

Four of the large galaxies in this image are close together in space, but the leftmost one is in the foreground by about 250 million light years. The others are all about 290 million light years away. The interaction between the top three galaxies that are near to one another is extraordinary. Bright red star-forming regions really pop out in this image, as do the jets emitted from the AGN in the top galaxy. There’s a nice tidal tail to the left of that topmost galaxy, and the merging galaxies right below that topmost one really give a sense of motion and inspiral.

The background to the quintet is also interesting, with lots of galaxies of various colors, sizes and shapes.  

Supporting material in the texts and online: This image provides a great opportunity to talk to students about “What an Astronomer Sees”--how astronomers draw meaning out of an image by closely examining shapes, colors and relationships. You might reference this image in the chapters on the Formation and Evolution of Structure, because it so clearly shows that galaxies merge and evolve. Other connected material appears in:

Exploration: Galaxy Classification, where this image could be substituted for the image shown. Students can zoom in and identify galaxies of each type on a printout or grid.

AstroTour: Active Galactic Nuclei, which relates to the AGN in the top galaxy.

Astronomy in Action Video: Size of Active Galactic Nuclei and Galaxy Shapes and Orientation.

Hubble Law, where the connection between redshift and distance (of galaxies in the background, for example) is made concrete.

The Learning Astronomy by Doing Astronomy Workbook, Activity 28: Light Travel Time and the Size of a Quasar can help students understand why they can’t actually SEE the AGN at the bottom of the jets in the topmost galaxy.

https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-delivers-deepest-infrared-image-of-universe-yet

Deep field images never disappoint, do they? For the novice astronomer, however, these images need quite a lot of interpretation. I usually start by identifying different types of objects in the image, and help students figure out how to identify them. The spikey objects are stars (objects like our Sun) in the foreground. These stars are bright enough that the bits of light deflected by the telescope itself are noticeable. (This is a gloss on diffraction, of course, but it’s enough for early in the semester!) A student might notice that the diffraction spikes.

The smaller, fainter objects are nearly all galaxies. This gives me the opportunity to mention what a galaxy actually is: a conglomeration of billions or trillions of stars, plus dust and gas. I’ll ask them to estimate the number of galaxies in this image, and accept any number that is in the thousands. So then I ask them to think about how many STARS are represented in this image—including the stars in the galaxies!

Next, I’ll point out that galaxies come in several shapes. I’ll point out a nice face-on spiral (there is a particularly nice one just above center on the right), and then an edge-on spiral (there are lots!). Then I’ll point out a smudgy elliptical galaxy, like the one near the center of the image.

I’ll mention that those are the two basic shapes of isolated galaxies, and then I’ll draw students’ attention to the gravitationally-lensed galaxies that appear as arcs along concentric circles around the big elliptical near the center of the image.

I’ll often ask students to notice the colors of the galaxies. At the beginning of the course, it’s too much to ask them to understand WHY more distant galaxies are redder, in general. But I ask them to notice that the galaxies shown have colors, and that distance is one of the things we can figure out from those colors.

Finally, I circle back to the most accessible big WOW of these kinds of images: a feel for the size of the universe. The image took 12.5 hours to build from lots of shorter images, and “zooms in” on a section of sky as small as a grain of sand held at arm’s length. In order to get a sense of the scale of the universe, students must imagine wallpapering the sky with grains of sand…and then replacing every single grain with an image like this one, including its thousands of galaxies.

Supporting material in the texts and online: This image provides a great opportunity to talk to students about “What an Astronomer Sees”--how astronomers draw meaning out of an image by closely examining shapes, colors, and relationships. You might reference this image in Chapter 1, as a final “zoom out” from the Figures that develop the universal address. Other connected material appears in:

The Light and Telescopes chapter, where diffraction makes an appearance (these are particularly beautiful diffraction spikes, if you are into that sort of thing!).

Evolution of High-Mass Stars, where it first becomes possible to discuss gravitational lensing.

Hubble Law, where the connection between redshift and distance is made concrete.

Formation and Evolution of Structure, which connects this image to the larger mission of JWST to find the first stars and galaxies, and finally answer these questions about how the universe has changed since very early times.

The Learning Astronomy by Doing Astronomy Workbook, Activity 32: Hubble Deep Field North is a great activity for introducing the ideas that could be explored by astronomers in the newer James Webb image.

Two related Astronomy in Action videos: Galaxy Shapes and Orientation and Expanding Balloon Universe.

We are so lucky to have a spiffy new telescope that has captured the public imagination over the summer! 

I used the first group of five images (one is really a spectrum, but for simplicity, I’ll refer to them all as images here!) to introduce the course to my Astro101 students this semester, and it was a hit!  Many of them had heard about the images over the summer, and a few had seen them.  But most of them, while they might have understood a particular image, hadn’t put the grouping together to ‘see the bigger picture’, which is that these five images span the history of the universe from shortly after it began to now.

I presented them in this order:

SMACS 0723 (the Webb Deep Field) I used this image to introduce the concept of the Universe as a whole object of a certain age, which has an observable size limited by that age.  I introduced a number of questions that I know my students would have, and promised to answer them once they’ve learned a few more things along the way…

Stephan’s Quintet This visual grouping of five galaxies includes a number of the signatures of interactions between galaxies, such as starburst regions and tidal tails. It’s a handy image to show to introduce the idea that the universe is not static, that even galaxies evolve over time.

Carina Nebula A nearby star-forming region starts to bring the discussion closer to home in both space and time. I’m often bemused to find that student do not know that stars are not eternal. This is a great image to show to talk about how stars form, and how we build that story from pictures like these.

Southern Ring Nebula  Stars are “born”, and they also “die”. When they die, they enrich the galaxy with the elements that form new stars, new planets, and sometimes people.

WASP-96 b I found a nice segue from the Southern Ring Nebula (all about elements in the galaxy) to detecting those elements using a spectrum like this one! Later in the course, they will find out more about how to read such an image, but for now it’s enough to be absolutely staggered that it’s possible to know that there is water in the atmosphere of a planet that orbits another star!

I’ll give a bit more information and background on these images in the next few blog posts, but presenting them on Day One, as a sort of “movie trailer” for the course turned out to be a great way to inspire students to ask questions, get talking, and be motivated to continue on.

I finished with a sketching activity which I have picked up and modified from a workshop I attended years ago. I show the students the image, and then have them sketch it 3 times: once in 15 seconds, once in 30 seconds, and once in three minutes.  By the third time they sketch the object, they are beginning to see things that they didn’t see in the first few seconds.  This emphasizes that sometimes they just need to slow down to understand or appreciate the material—a lesson I am always trying to teach! 

Summary: As we all know, and is explained in the text, dark matter is “a thing”, but we still don’t know much more about it than that it exists. Lately particle physicists have been getting excited about the possibility that dark matter consists of axions. I found these two recent review articles (February issue of Science Advances) to be very helpful.  They reminded me of particle physics that I had forgotten, caught me up on the arguments that particle physicists are making in favor of axion dark matter, and helped me understand the observational strategy to try to detect axions.  These are not articles for introductory astronomy students to read; they are written at far too high a level.  But they may be useful for busy astronomy teachers, who need a refresher about the issue---just in case this turns out to be the answer!

Articles:

What is it?  

How might we observe it?  

For several years now, I have met the “science and society” general education learning goal with a unit on climate change.  This year, SpaceX gave me another option, with the latest installment of the planned 42,000 satellite constellation known as Starlink.  I had strong feelings when 40 satellites were destroyed at launch by a solar storm, and I shared those feelings with students.  We had the opportunity for a free-ranging discussion in class about the tension between technological advances and preserving the resources we hold in common.

There were many articles, but here’s one:

A few other resources that might be useful:

The Starlink Situation   (last update 3/2020)

Starlink and the Astronomers (an update from 4/2020)

How do Starlink Satellites Work?

It also affects radio astronomy 

A web search for “starlink astronomy images” tends to yield images taken shortly after launch, with a large number of satellite tracks from the latest batch.

About the cost of Starlink internet (the article includes both premium and standard rates)

IAU’s stance

In this four-part series, Dr. Stacy Palen will discuss her own journey toward recognizing and addressing issues of equity in the Astro 101 classroom. We encourage this to be an open communication and discussion through the comment section below.

To read the previous post, follow the link here.

Addressing Equity in Astronomy IV: It’s Different for Everyone

Addressing equity in the classroom is complex, and a moving target. There is a lot of pressure to modify a lot of teaching methods to be more inclusive: have flexible deadlines, creative grading policies, invite informality in the classroom, etc.  But these methods sometimes have unintended consequences for particular faculty members.

Consider this article in the Chronicle of Higher Education: https://www.chronicle.com/article/academe-has-a-lot-to-learn-about-how-inclusive-teaching-affects-instructors?cid2=gen_login_refresh&cid=gen_sign_in

Different faculty need to behave differently in the classroom, in order to be perceived as the “competent”. Of all the faculty in my Department, I am the only one who has been called “obstinate” by a student because I insisted that he learn to write proper lab reports with error bars on his graphs. Other faculty are far worse sticklers than I am, but by nature of their personal attributes, their feedback to students is accepted more readily. I cannot “get away” with being on a first-name basis with my students, or with having an open-door policy, as some of my colleagues can.  How do I know? I tried it. The boundaries fell, and I was swamped by people who were not even my students but wanted help with their coursework assigned by my colleagues.  My colleagues would ask for advice on how to get students to come to their office hours. “Smile more,” I would say, somewhat tongue in cheek.

I believe learning is different for everyone---what motivates any given student, and what works for them is deeply individual. In the same way, teaching is different for everyone---what works for you is deeply individual. Teaching is not a Shakespeare play, with a pre-determined set of lines to say and movements to make across the stage.  Teaching is improv (sometimes comedy) where the action can go in all sorts of directions along the way to telling the story.

All of which to say: be kind to yourself and your colleagues as you figure out how to teach more equitably. What works for you may not work for them; what works for them may not work for you. If you receive advice to try something…but it doesn’t work, abandon it, and try something else. Experiment! Tell your students that you are experimenting, and why, so that they can give you good feedback about how your experiments affect them.  Not only will you find surprising ways to engage students, but this will help you stay engaged in the process of teaching.  I suspect all of us could use a little help with that just now.