Jason Kendall
I taught introductory Astronomy at William Paterson University from 2011 to 2020, and at CUNY Hunter from 2016 to 2018. In my years of teaching, I tried to make my class innovative and interesting, featuring unique assignments and activities. I've also created a series of over 100 videos covering most of introductory Astronomy. These videos are rigorous enough to be possibly used as a low-level, self-taught Astrophysics class.
Most of the videos on this channel are geared towards a full intro astronomy course. It contains all the content of a typical undergraduate course, and then some.
If you like what you see, please consider supporting me through Patreon.
Jason Kendall
Why are star clusters ideal "laboratories" for stellar evolution?
14 hours ago | [YT] | 10
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Jason Kendall
The star Betelgeuse is a Supergiant red star. What will happen to it within the next million years, or sooner?
A) It will swell up to become a blue supergiant, like Rigel.
B) It will shed off its outer layers just like what happened to a similar star in what is now the Orion Nebula.
C) It will explode as a supernova, becoming visible in the daytime sky.
D) It will continue to change size and temperature for another 20 million years, becoming the nearest planetary nebula.
1 day ago | [YT] | 15
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Jason Kendall
What is the importance of 1.4 solar masses in stellar evolution?
2 days ago | [YT] | 18
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Jason Kendall
Why don't we see the most common stars of the Galaxy in HR Diagrams?
3 days ago | [YT] | 15
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Jason Kendall
A very important note popped in the comments, so I'm revising an older one!
The star Sigma Draconis has a parallax of 173 milli-arcseconds, while the star Ross 128 has a parallax of 300 milli-arcseconds. What can you correctly conclude?
3 days ago | [YT] | 16
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Jason Kendall
Why were Type Ia supernovae so critical in discovering dark energy?
A) They were used to trace the chemical evolution of early galaxies, revealing patterns of heavy-element formation that suggested the universe was expanding differently than astronomers had originally assumed.
B) They allowed astronomers to map the distribution of dark matter in galaxy clusters, providing indirect evidence that unexpected gravitational effects were influencing the large-scale structure of the universe.
C) These brilliant explosions are consistent standard candles, visible out to billions of light years. Instead of finding the most distant galaxies slowing down as expected in a closed universe, the supernovae were even more distant than expected, as dark energy kept the universe forever expanding.
D) They made it possible to measure the ages of very old stars with high precision, leading scientists to realize that the universe’s expansion history must have been altered by an additional, previously unknown form of energy.
4 days ago | [YT] | 16
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Jason Kendall
Why do we see different constellations in the Summer than in the Winter?
A) Because Earth’s rotation axis wobbles over thousands of years.
B) Because the Moon’s orbit blocks different parts of the sky at different times of year.
C) Because Earth orbits the Sun, so nighttime faces a different part of the sky in different seasons.
D) Because the stars move rapidly relative to the Sun over the course of a year.
6 days ago | [YT] | 18
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Jason Kendall
Why do Galileo's observations of Venus help prove that Earth orbits the Sun and not the other way around?
A) Galileo observed Venus moving in retrograde motion, which could only occur if Earth was fixed at the center while all other planets orbited it in complex paths, contradicting the geocentric model.
B) Galileo measured the distance to Venus directly and found it was closer to the Sun than to the Earth, proving that the Sun was the true center of the solar system and that Earth moved around it.
C) Galileo noticed that Venus’s brightness varied randomly over time, which matched predictions from the heliocentric model but could not be explained by any geocentric configuration.
D) Galileo saw that Venus had phases similar to the Moon, which could be explained only if Venus orbited the Sun, showing that the Sun, not the Earth, is at the center of the planetary system.
1 week ago | [YT] | 15
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Jason Kendall
Which of the following best describes the horizon problem and how cosmic inflation addresses it?
A) The horizon problem is that distant galaxies are moving away too slowly; inflation solves this by speeding up their motion.
B) The horizon problem is that the universe appears too old; inflation solves this by making the universe expand more gradually.
C) The horizon problem is that regions of the universe far apart from each other have nearly the same temperature, even though they should not have been able to exchange information or heat. Inflation solves this by proposing that these regions were once close together before rapidly expanding.
D) The horizon problem is that the cosmic microwave background (CMB) is too bright; inflation solves this by stretching the light to dim it.
1 week ago | [YT] | 10
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Jason Kendall
What is the definition of a parsec?
A) It is defined to be the distance corresponding to an angular shift of 1 arcsecond of an object in the sky (such as a distant star) taken 6 months apart.
B) It is defined to be 3.26 light years.
C) It is defined to be the angular shift of a distant object that is seen from two different vantage points.
D) It is defined to be the time it takes for light to reach the Earth from the Sun compared to the time it takes for light to reach the Earth from the Moon.
1 week ago | [YT] | 18
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