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Astronomy: explore STEM content (page 22 of 26) · openstem

All fields Software Mathematics Physics Chemistry Biology Engineering Astronomy Environmental Other Astronomy Astronomy groups

Explore STEM Content

Search the community's STEM library — free to study, yours to make your own.

Astronomy

Stars, orbits, cosmology and observation on openstem — flashcards, notes, quizzes and plots shared by the community. Study free, or clone anything into your library.

Content Groups1

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Collection3 items

01Astronomy · L4 · The Cosmic Distance Ladder, Quantitatively

02Astronomy · L4 · The cosmic distance ladder: parallax, Cepheids, and Type Ia supernovae

03Astronomy · L4 · The Cosmic Distance Ladder, Quantitatively — 4 Q

Astronomy

Astronomy · L4 · The Cosmic Distance Ladder, Quantitatively

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Astronomy · L4 · The Cosmic Distance Ladder, Quantitatively

Flashcards11 cards

What distinguishes a planet from a dwarf planet under the IAU 2006 definition?1 / 11

A planet (IAU 2006) must: (1) orbit the Sun, (2) have sufficient mass for gravity to achieve a roughly spherical shape (hydrostatic equilibrium), AND (3) have cleared the neighbourhood around its orbit of other debris. A dwarf planet meets criteria 1 and 2 but NOT 3. Pluto was reclassified as a dwarf planet because it shares its orbit with Kuiper Belt objects. The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

Astronomy

Astronomy · L4 · The Solar System — Planets & Their Properties

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Astronomy · L4 · The Solar System — Planets & Their Properties

Collection4 items

01Astronomy · L2 · The Space Race

02Astronomy · L2 · The Space Race

03Astronomy · L2 · Space Race Timeline

+1 more

Astronomy

Astronomy · L2 · The Space Race

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Astronomy · L2 · The Space Race

Note~377 words · 2 min

Magnetically Powered Neutron Stars A magnetar's defining feature is an extreme surface magnetic field, B ~ 10¹⁴–10¹⁵ G, roughly two to three orders of magnitude above a typical pulsar's. The Thompson & Duncan magnetar model argues this fiel

Astronomy

Astronomy · L5 · Magnetars: Extreme Fields, Giant Flares, and the Fast Radio Burst Connection

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Astronomy · L5 · Magnetars: Extreme Fields, Giant Flares, and the Fast Radio Burst Connection

Flashcards8 cards

What is light pollution?1 / 8

Excessive or poorly directed artificial light that brightens the night sky, making it harder to see stars and other faint objects.

Astronomy

Astronomy · L2 · Light Pollution and Dark Skies

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Astronomy · L2 · Light Pollution and Dark Skies

Collection4 items

01Astronomy · L5 · Baryogenesis

02Astronomy · L5 · Baryogenesis and the Sakharov Conditions

03Astronomy · L5 · From Leptogenesis to the Observed Baryon Asymmetry

+1 more

Astronomy

Astronomy · L5 · Baryogenesis

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Astronomy · L5 · Baryogenesis

Note~325 words · 2 min

Millisecond Pulsars as Galactic Clocks A pulsar timing array turns a network of millisecond pulsars into a single, galaxy-sized gravitational-wave detector. Each pulsar's rotation is modelled with extreme precision (spin frequency and spin-

Astronomy

Astronomy · L5 · Pulsar Timing Arrays and the Nanohertz Gravitational-Wave Background

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Astronomy · L5 · Pulsar Timing Arrays and the Nanohertz Gravitational-Wave Background

Quiz4 questions

Roughly what is the Eddington luminosity of a 5 M☉ black hole? (L_Edd ≈ 1.26×10³⁸ erg/s per solar mass)

A~2.5×10³⁷ erg/sB~1.26×10³⁸ erg/sC~6.3×10³⁸ erg/sD~1.26×10³⁹ erg/s

Astronomy

Astronomy · L5 · Accretion Disk Physics

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Astronomy · L5 · Accretion Disk Physics

Note~299 words · 1 min

Worlds Around Other Stars An exoplanet is any planet orbiting a star other than the Sun. The first one confirmed around a Sun-like star, 51 Pegasi b, was found in 1995. Since then, the count has exploded — astronomers have now confirmed mor

Astronomy

Astronomy · L2 · Exoplanets

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Astronomy · L2 · Exoplanets

Quiz4 questions

If a galaxy's visible mass were the only mass present, the naive Keplerian expectation is that orbital velocity at large radius should:

AStay perfectly flatBIncrease linearly with radiusCDecline as 1/√rDDrop to zero abruptly

Astronomy

Astronomy · L4 · Galactic Dynamics & Dark Matter — 4 Q

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Astronomy · L4 · Galactic Dynamics & Dark Matter — 4 Q

Flashcards8 cards

What defines an ultra-high-energy cosmic ray (UHECR)?1 / 8

A cosmic ray — almost always a proton or atomic nucleus — with energy above roughly 10^18-10^19 eV (an EeV, or exa-electronvolt), far beyond what any Earth-based particle accelerator can produce. The most extreme detected events reach energies over 10^20 eV, concentrated into a single subatomic particle.

Astronomy

Astronomy · L5 · Ultra-High-Energy Cosmic Rays & the GZK Cutoff

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Astronomy · L5 · Ultra-High-Energy Cosmic Rays & the GZK Cutoff

Flowchart9 objects

Astronomy

Astronomy · L4 · Asteroseismology and helioseismology: reading stellar interiors from oscillations · flowchart

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Astronomy · L4 · Asteroseismology and helioseismology: reading stellar interiors from oscillations · flowchart

Quiz7 questions

What is a mean-motion resonance?

ATwo orbits with completely unrelated, random periodsBTwo orbital periods forming a ratio of small whole numbers, so gravitational tugs repeat coherently at the same phaseCTwo bodies orbiting in exactly opposite directionsDA resonance that only occurs between stars, never planets or asteroids

Astronomy

Astronomy · L4 · Orbital Resonances, Lagrange Points & the Restricted Three-Body Problem

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Astronomy · L4 · Orbital Resonances, Lagrange Points & the Restricted Three-Body Problem

Note~171 words · 1 min

You Don't Need a Telescope to Start Some of the best stargazing happens with nothing more than your own eyes. Learning a few simple tricks can help you find stars, planets, and famous patterns in the night sky. Telling Planets from Stars Pl

Astronomy

Astronomy · L1 · Finding Stars & Planets in the Sky

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Astronomy · L1 · Finding Stars & Planets in the Sky

Flowchart17 objects

Astronomy

Astronomy · L4 · From the equivalence principle to observational tests of GR

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Astronomy · L4 · From the equivalence principle to observational tests of GR

Flashcards8 cards

How does the transit method detect an exoplanet?1 / 8

By watching a star's brightness over time and looking for a small, periodic dip caused by a planet passing directly in front of it, blocking a tiny fraction of its light.

Astronomy

Astronomy · L3 · Exoplanet Detection

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Astronomy · L3 · Exoplanet Detection

Note~250 words · 1 min

Sorting Galaxies by Shape Edwin Hubble classified galaxies by their visual shape into a scheme still used today, sometimes called the 'Hubble tuning fork' for the shape of its diagram. Spirals are rich in gas and dust and actively forming n

Astronomy

Astronomy · L3 · Galaxy Types & the Milky Way

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Astronomy · L3 · Galaxy Types & the Milky Way

Note~665 words · 3 min

Stars and stellar evolution: from nebula to remnant Stars are self-gravitating balls of plasma held together by gravity and powered by nuclear fusion in their cores. Their life histories depend critically on their initial mass — from sub-st

Astronomy

Astronomy · L4 · Stars and stellar evolution: from nebula to remnant

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Astronomy · L4 · Stars and stellar evolution: from nebula to remnant

Collection4 items

01Astronomy · L4 · Interplanetary Trajectory Design

02Astronomy · L4 · Interplanetary trajectory design: patched conics, delta-v, and gravity assists

03Astronomy · L4 · Designing an interplanetary trajectory: patched conics and the gravity-assist option

+1 more

Astronomy

Astronomy · L4 · Interplanetary Trajectory Design

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Astronomy · L4 · Interplanetary Trajectory Design

Flashcards8 cards

What is gravitational-wave strain h, and how large is it for real detections?1 / 8

Strain is the fractional change in proper distance a gravitational wave induces:

Astronomy

Astronomy · L5 · Gravitational Waves

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Astronomy · L5 · Gravitational Waves

Flowchart15 objects

Astronomy

Astronomy · L2 · Auroras and Earth's Magnetosphere · flowchart

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Astronomy · L2 · Auroras and Earth's Magnetosphere · flowchart

Note~208 words · 1 min

A Moon That Never Changes Shape The Moon looks different almost every night. Some nights it is a thin sliver. Other nights it is a bright, full circle. But here is the secret: the Moon itself never changes shape at all. The Moon is a giant

Astronomy

Astronomy · L1 · The Changing Moon

@openstem

Astronomy · L1 · The Changing Moon

Quiz5 questions

What are the three stages of impact crater formation, in order?

AExcavation, contact and compression, modificationBContact and compression, excavation, modificationCModification, excavation, contact and compressionDCompression, ejection, vaporisation

Astronomy

Astronomy · L3 · Asteroid Impacts & Craters

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Astronomy · L3 · Asteroid Impacts & Craters

Flashcards8 cards

What is a meteor shower?1 / 8

An event where many meteors, or 'shooting stars', appear in a short time, seeming to come from one part of the sky.

Astronomy

Astronomy · L1 · Meteor Showers

@openstem

Astronomy · L1 · Meteor Showers

Quiz4 questions

What mainly causes Earth's seasons?

AEarth's changing distance from the SunBEarth's tilted axisCThe Moon's phasesDClouds blocking sunlight

Astronomy

Astronomy · L1 · The Four Seasons Quiz

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Astronomy · L1 · The Four Seasons Quiz

Quiz4 questions

What physically produces the CMB's series of acoustic peaks?

ARandom instrumental noise in CMB telescopesBStanding sound-wave oscillations in the pre-recombination photon–baryon fluid, frozen in at recombinationCDoppler shifts from the Milky Way's own motionDGravitational lensing by foreground galaxy clusters

Astronomy

Astronomy · L5 · The CMB Angular Power Spectrum

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Astronomy · L5 · The CMB Angular Power Spectrum

Flowchart15 objects

Astronomy

Astronomy · L4 · The unified AGN model: same engine, different viewing angle

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Astronomy · L4 · The unified AGN model: same engine, different viewing angle

Quiz4 questions

What best describes Low Earth Orbit (LEO)?

AVery high altitude with a 24-hour periodBLow altitude, roughly 90-minute orbital periodCAn orbit only around the MoonDAn orbit that never moves relative to the stars

Astronomy

Astronomy · L2 · Satellite Orbits and GPS

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Astronomy · L2 · Satellite Orbits and GPS

Note~596 words · 3 min

Biosignature gases, the Fermi paradox, and habitability beyond the classical HZ Astrobiology sits at the intersection of chemistry, planetary science, and statistics: what atmospheric signatures would convincingly indicate life, why has no

Astronomy

Astronomy · L4 · Biosignature gases, the Fermi paradox, and habitability beyond the classical HZ

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Astronomy · L4 · Biosignature gases, the Fermi paradox, and habitability beyond the classical HZ

Collection3 items

01Astronomy · L5 · Stellar Atmospheres and Spectral Line Formation

02Astronomy · L5 · Spectral Line Formation, the Curve of Growth, and Non-LTE Effects

03Astronomy · L5 · Stellar Atmospheres and Spectral Line Formation

Astronomy

Astronomy · L5 · Stellar Atmospheres and Spectral Lines

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Astronomy · L5 · Stellar Atmospheres and Spectral Lines

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