1000 Sunsets at Mount Laguna Observatory (with narration) Robert Quimby 2026-09-29 | 1000 Sunsets at Mount Laguna Observatory (with narration)
Spin me right round Robert Quimby 2025-06-18 | Watch the Milky Way rise and set in two full-night timelapses. The video opens with a dynamic pan-and-scan simulating a spinning camera, and ends with a fixed north-facing view that lets the Earth do all the spinning. Each sequence runs from the end of dusk to the start of dawn.🎥 Want to control the view yourself?Check out the linked 360° VR version of this timelapse! Move your phone or drag your screen to look around and create your own version of this short — you're the director of your own cosmic journey.📍 Captured at: Mount Laguna Observatory in San Diego County, California, USA🦉 Yep, that’s an owl photobombing the opening!#Timelapse #MilkyWay #YouSpinMeRound #DeadOrAlive #360Video
Click for 360° Timelapse Robert Quimby 2025-06-18 | Watch stars, planets, and satellites drift over the Mount Laguna Observatory in east San Diego County in this two night timelapse. Move your phone, click and drag the screen, or put on your VR headset to see the 360° view.For more details, see youtu.be/iajnIjMctUw
Four Seasons: Sunrise to Sunset Robert Quimby 2025-05-24 | The path of the Sun through the sky in each of the four seasons set to Vivaldi's "Four Seasons". 🤔 Why are the days longer in the summer and shorter in the winter? The North Pole tilts toward the Sun in June (and the South Pole tilts away), so as the Earth spins around each day the northern hemisphere spends more time facing the Sun (and the southern hemisphere spends less). At the North Pole, the Sun never sets in June (at the South Pole it never rises). ☀️ In this short, you can see the Sun rise highest in the sky and stay up longest in June at the Mount Laguna Observatory in San Diego County, California, USA. ❄️ Six months later in December, the North Pole tilts away from the Sun (and the South Pole tilts toward it), so we get less sunlight in the northern hemisphere (and more in the southern hemisphere). In this short notice that the Sun rises less than half as high in the sky in December. 🌸 The Spring and 🍂 Autumn equinoxes occur when the Poles are neither tilted toward or away from the Sun. Thus, everywhere on Earth the Sun rises almost due East and sets almost due West. On these days there is about 12 hours of day and 12 hours of night everywhere on Earth (equinox is latin for "equal night"). 👀 Notice that the paths of the Sun through the sky near the Spring equinox is almost the same as its path near the Autumn equinox. But, if you look closely, you will notice that by the end of the day the Sun moves slightly north during the day in the Spring and slightly south during the day in the Autumn. The the path of the Sun is (basically) always changing. 📷 Images from 5 different cameras were used to make this short: four HPWREN cameras giving a color view of the horizon and ground, and one monochrome camera providing a (colorless) view of the sky. All cameras are located at the Mount Laguna Observatory, but the sky camera is stationed in a different part of the observatory. 🧠 The Sun's maximum height can be calculated for any day as: MAX_SUN_ALT = POLE_TILT + POLAR_ANGLE, where POLE_TILT is the angle the closest pole is titled toward from the Sun (+23.5 degrees in the summer, -23.5 degrees in the winter), and POLAR_ANGLE is how far you are from the pole in degrees (for example, Mount Laguna has a latitude of about 33 degrees, so its POLAR_ANGLE is 90 - 33 = 57 degrees).
Four Seasons: Sunrise to Sunset (B&W) Robert Quimby 2025-05-24 | The path of the Sun through the sky in each of the four seasons set to Vivaldi's "Four Seasons". 🤔 Why are the days longer in the summer and shorter in the winter? The North Pole tilts toward the Sun in June (and the South Pole tilts away), so as the Earth spins around each day the northern hemisphere spends more time facing the Sun (and the southern hemisphere spends less). At the North Pole, the Sun never sets in June (at the South Pole it never rises). ☀️ In this short, you can see the Sun rise highest in the sky and stay up longest in June at the Mount Laguna Observatory in San Diego County, California, USA. ❄️ Six months later in December, the North Pole tilts away from the Sun (and the South Pole tilts toward it), so we get less sunlight in the northern hemisphere (and more in the southern hemisphere). In this short notice that the Sun rises less than half as high in the sky in December. 🌸 The Spring and 🍂 Autumn equinoxes occur when the Poles are neither tilted toward or away from the Sun. Thus, everywhere on Earth the Sun rises almost due East and sets almost due West. On these days there is about 12 hours of day and 12 hours of night everywhere on Earth (equinox is latin for "equal night"). 👀 Notice that the paths of the Sun through the sky near the Spring equinox is almost the same as its path near the Autumn equinox. But, if you look closely, you will notice that by the end of the day the Sun moves slightly north during the day in the Spring and slightly south during the day in the Autumn. The the path of the Sun is (basically) always changing. 📷 Images were taken with a monochrome camera, which is why there is no color.🧠 The Sun's maximum height can be calculated for any day as: MAX_SUN_ALT = POLE_TILT + POLAR_ANGLE, where POLE_TILT is the angle the closest pole is titled toward from the Sun (+23.5 degrees in the summer, -23.5 degrees in the winter), and POLAR_ANGLE is how far you are from the pole in degrees (for example, Mount Laguna has a latitude of about 33 degrees, so its POLAR_ANGLE is 90 - 33 = 57 degrees).
Lunar Analemma #astronomy #timelapse Robert Quimby 2025-02-09 | One picture of the Moon every 24 hours, 50 minutes and 28 seconds (approximately) showing the Lunar Analemma.Each time the Earth spins around, the Moon has moved a little in is orbit, so it is not in the same place it was the day before. It takes about an extra 50 minutes for the same side of the Earth to face the Moon each day on average, but the exact time depends on how fast the Moon is moving. The Moon moves faster in its orbit when it is closer to the Earth. This produces the east-west motion in the Lunar Analemma. The Moon's orbit is also tilted compared to the Earth's spin axis. So sometimes the Moon is south of the Earth's equator, and sometimes it is North. As viewed from Earth, this produces the north-south motion in the Lunar Analemma.The shape of the Lunar Analemma changes with time. Some months the shape resembles a figure 8, but the crossover point in the middle can slide to the southern or northern limits resulting in a more paddle-shaped loop. This change is due to precession of the Moon's orbit--the axis of revolution and the direction of the orbit's major axis both change over time due to the gravitational pull of the Sun, Jupiter, and other objects in the solar system.In this short, I mark the position of the Moon in each image with a green circle. These circles are always larger than the apparent diameter of the Moon, although sometimes the Moon is over exposed and the glare around the Moon might make it look bigger. I shade these circles to indicate the phase of the Moon. The Moon can be difficult to see when it appears closer to the direction of the Sun. Notice that this always occurs when the Moon is in its crescent phase.Images for this video were taken by the East-facing HPWREN camera at the Mount Laguna Observatory in San Diego County, California. The music is a masterful performance by Alexis Weissenberg of "Clair de lune" by Debussy. The full performance is available here: youtube.com/watch?v=w1t0NOZIeJs
Daylight Saving Switch #timelapse #astronomy Robert Quimby 2024-11-03 | Pictures of the Sun in the morning (top) and evening (bottom) every day of the year at the "same" clock time. In California, we have Daylight Saving time (sometimes written "Daylight Savings"), which is when we change our clocks to take one hour of sunlight from the morning and add it to the evening. This does not change the total amount of daylight.The amount of daylight does naturally change throughout the year as the Earth orbits the Sun. The Earth spins, and its north pole tilts away from the Sun in January, so in California and the rest of the northern hemisphere we get less sunlight. But in July the Earth's north pole tilts toward the Sun, giving California more hours of sunlight. This is why the Sun appears higher in the sky at the same time in July than in January. By law, in California we currently change our clocks to Daylight Saving Time the second Sunday in March and back to Standard Time the first Sunday in November. Note that Daylight Saving occurs in the summer when the days are the longest, not in winter when you might want a little extra sun. And again, Daylight Saving does not actually increase the amount of sunlight we get. That is determined by the laws of nature, not governments. This video was made using pictures from the HPWREN cameras at the Mount Laguna Observatory in San Diego County, California, USA.
Star goes nova #timelapse #astronomy Robert Quimby 2024-10-21 | Ancient astronomers occasionally discovered "guest stars" in familiar constellations. These were called "stella nova" in latin ("new star" in English). In modern astronomy, a "nova" is an explosion on the surface of a star that makes it appear much brighter, and a "supernova" is a larger explosion that destroys the star.On June 12, 2021 (UT) a faint star in Hercules suddenly became visible to the naked eye. This nova outburst, known as Nova Herculis 2021 (or V1674 Her) was caught in the act by a telescope array at the Mount Laguna Observatory in San Diego County. This short was made by combining images from the observatory's all-sky camera and views through the telescope array.
The Stars Every Night for a Year #timelapse #astronomy Robert Quimby 2024-10-01 | Ever notice that you see different stars on different days of year? At night, your side of the Earth faces away from the Sun. As the Earth moves around the Sun, the night-shaded side of the Earth faces a different part of the Celestial Sphere. After 1 year, the Earth completes its orbit around the Sun and we see the same stars once again. You can observe the Earth revolving around the Sun by looking in the same direction at the same time each night and noting the changing stars. This short does just that. It shows one image looking straight over head taken once every 24 hours for a year. Notice that the stars appear to spin around the North Star. But we are not seeing the daily spin of the Earth; instead, we see the yearly revolution of the Earth around the Sun.Images were taken with the All-Sky Camera at the Mount Laguna Observatory in San Diego County. North is up, South is down, and the middle of the image is looking straight up.
Solar Analemma #timelapse #astronomy Robert Quimby 2024-10-01 | One picture of the Sun in the West every 24 hours for a year. Watch as the Sun traces out a figure 8 in the sky. The shape of this path is known as the solar analemma.Why does the position of the Sun change each day? The Earth spins and revolves around the Sun, but the Earth's spin is tilted compared to its orbit. In June the Earth's North Pole tilts toward the Sun, and in December it tilts away. This makes the Sun appear to shift North and South from one day to the next and creates the north-south motion in the analemma.It takes the Earth about 23 hours and 56 minutes to spin once, but because it is also moving in its orbit, the Earth has to spin a few minutes more for the same side to face the Sun. This is why the average solar day is 24 hours. The Earth's orbit is elliptical, and the Earth moves faster in its orbit when it is closer to the Sun. So sometimes the Earth has to spin for more than 24 hours to return the same side to face the Sun, and sometimes it takes less time. This creates the east-west motion in the analemma.This video was made from a series of pictures taken by the HPWREN cameras at the Mount Laguna Observatory in San Diego County.
What is retrograde? #shorts #timelapse #astronomy Robert Quimby 2024-09-26 | Planets usually move EAST through the Zodiac, but sometimes they appear to turn around and move WEST. Why? All the planets orbit the Sun, but planets closer to the Sun complete their trips around the Sun faster. Earth has an inside track compared to Mars, Jupiter, and Saturn, and as we lap them they appear to move backwards (relative to us). This is retrograde motion.This short shows a roughly southeast view, so EAST is left (←) and WEST is around to the right (→).Images are from the HPWREN cameras at the Mount Laguna Observatory in San Diego County. The images were taken about once every 23 hours and 56 minutes, which is the time it takes the Earth to spin once. With this time interval, the stars are seen in the same position each image, which makes it easy to see the planets move around the Celestial Sphere.The music is "Wandering Star" by Portishead. Listen to the full song here: youtu.be/8T0cRt8efsQ
Moon, stars, Jupiter and Mars! #shorts #timelapse Robert Quimby 2024-09-22 | The Moon rises, the setting Sun casts long shadows, the sky darkens, and the stars rise. Next come the planets. All following the words of Frank Sinatra!(In other words) This short shows images captured by the east-facing HPWREN camera at the Mount Laguna Observatory in San Diego county.
Jupyter Notebooks Robert Quimby 2024-01-18 | What is a Jupyter notebook? Introduction with demonstration of how to open a Jupyter notebook, how to edit one, and how to run markdown and code cells.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Unix/Linux (the basics) Robert Quimby 2023-08-15 | Introduction to Linux including what operating systems do, the "terminal" program, creating files and directories (folders), and pro tips on working from the command line.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
python debugger Robert Quimby 2023-08-15 | How to use the debugger built into ipython (including jupyter notebooks) to learn why your code crashes. Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Jupyter Notebooks (old version) Robert Quimby 2023-08-15 | [A new video is available at youtu.be/azM7W8vIWMI ] What is a Jupyter notebook? Introduction with demonstration of how to open a Jupyter notebook, how to edit one, and how to run markdown and code cells.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Python Robert Quimby 2023-08-15 | Quick introduction to python with a demonstration of creating variables of the basic data types (integer, string, lists, etc.) using the interactive python interpreter (in a jupyter notebook).Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Python Functions Robert Quimby 2023-08-15 | Demonstration of how to define and use functions in python with discussion of variable scope (how python looks up the value of variables in different blocks of code).Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
numpy Robert Quimby 2023-08-15 | Creation and use of 1-D and 2-D arrays in python using the numpy package. Includes demonstration of accessing subsections (slices) of arrays and numpy's ability to quickly perform numerical operations over entire arrays of data.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
matplotlib Robert Quimby 2023-08-15 | Covers the basics of using matplotlib in a python jupyter notebook to plot points and curves. Includes discussion of how to change the size of a figure, label the axes, and how to change the label font.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
astropy Robert Quimby 2023-08-15 | Quick introduction to astropy including some of the key features of the units, coordinates, time, and io sub packages. Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
FITS format Robert Quimby 2023-08-15 | Introduction to the FITS format commonly used by astronomers starting with discussion of the file structure followed by practical demonstration of loading header and image data into a python and using DS9 (and pyds9 in python) to view the data.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Coordinate Matching Robert Quimby 2023-08-15 | How to compare two lists of sky positions to find the closest matching coordinates beginning with discussion of how angular separations are calculated followed with a demonstration of how minimizing these separations can identify the most likely matches between lists. Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Statistical Distributions Robert Quimby 2023-08-15 | Introduction to using statistics to predict the odds of different outcomes in nature. Covers calculation of the probability of rolling 2 threes on 2 dice, expectation values, the binomial distribution, and its connection to the Poisson and Gaussian distributions. Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Telescopes Robert Quimby 2023-08-15 | Introduction to different types of telescopes and discussion of plate scale, conic sections, and the commonly sued Ritchey–Chrétien telescope design. Includes a simple ray-tracing example in python.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
CCDs Robert Quimby 2023-08-15 | Quick explanation of how CCDs work including photoexcitation of Valence electrons into the conduction band, isolating collected charges on individual pixels, and moving collected charges to the read out amplifier for measurement. Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.See also the javascript CCD demonstrator at https://rquimby.sdsu.edu/ccd.html
Image Processing Robert Quimby 2023-08-15 | How to process raw CCD images to remove bias and flat field to correct for pixel-to-pixel sensitivity differences.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.See also the javascript CCD demonstrator at: https://rquimby.sdsu.edu/ccd.html
Creating 3-color Images Robert Quimby 2023-08-15 | Discussion of how the human eye senses color, how combinations of red, green, and blue light can fool your eye into seeing other colors, and how you can use this to combine monochromatic images into 3-color images. Demonstration of using python and DS9 to create 3-color images from astronomical images recorded in different bands.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
LaTeX Robert Quimby 2023-08-15 | Introduction to LaTeX and how it can be used to create academic papers with beautiful equations. Basics of LaTeX tags, inserting comments, and including figures. Overview of overleaf.com.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Least Squares Fitting Robert Quimby 2023-08-15 | How to fit a model to data in the least-squares sense when you have more data than model parameters. Demonstration in python using numpy matrices including estimation of model parameter uncertainties.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Least-squares fitting with a shift Robert Quimby 2023-08-15 | Demonstration of how a coordinate shift can reduce the estimated uncertainty in some model parameters using python.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Uncertainty Propagation Robert Quimby 2023-08-15 | How to determine the uncertainty in a calculated quantity given uncertainties in the values used in the calculation (sometimes called error propagation). Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Application of Least-Squares Fitting Robert Quimby 2023-08-15 | Example of least-squares fitting showing how two systems of equations can be solved simultaneously. The example uses python to determine the mapping between celestial coordinates (R.A., Dec.) and image pixel coordinates (x, y). Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Sigma Clipping Robert Quimby 2023-08-15 | How to remove outliers from a (Gaussian) distribution using iterative estimation of the sample median and standard deviation.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Photometry Robert Quimby 2023-08-15 | How to measure the light from a celestial source excluding background light using the photutils package in python.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
scipy Robert Quimby 2023-08-15 | Introduction to some of the key features of the scipy package including a demonstration of fmin in the optimize sub package. Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
chi-square fitting Robert Quimby 2023-08-15 | How to calculate the chi-square value for a given model and dataset, and how adjusting the model parameters to minimize the chi-square can be used to find the best-fit model parameters.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Lomb-Scargle Periodogram Robert Quimby 2023-08-15 | How to convert values measured over time into a periodogram with power measured at a set of frequencies using the Lomb-Scargle method in python and how this periodogram can be used to determine the period of an astrophysical signal. Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Bootstrap Robert Quimby 2023-08-15 | How to use resampling with replacement to evaluate the uncertainty in your analysis. Introduction to the bootstrap method, comparison to uncertainty propagation, and python demonstration of how bootstrap may be used to reveal unknown uncertainties. The related Jackknife resampling method is further discussed. Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
astroquery Robert Quimby 2023-08-15 | Introduction to the astronomical data aggregators SIMBAD, NED, and VizieR with a demonstration of how the astroquery package can be used to retrieve data from these sources into your python session. Further discussion of how to search for academic papers using ADS.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
SQL Robert Quimby 2023-08-15 | Introduction to the Structured Query Language (SQL) with basic demonstration of how to select specific records from a SQLite database using sqlite3 and pandas in python.Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
Kolmogorov–Smirnov (KS) Testing Robert Quimby 2023-08-15 | Discussion of using the Kolmogorov–Smirnov (KS) method to test (reject) if to samples are drawn from the same parent population. Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques. Students should complete these notebooks as they watch the video.
GitHub Robert Quimby 2023-08-15 | Explanation of what GitHub is and how to use "git" from the command line to share files (demonstration included).Part of the Astronomical Techniques series developed for advanced undergraduate and beginning graduate students at San Diego State University. The accompanying Jupyter notebook can be found at github.com/rmquimby/Astronomical_Techniques . Students should complete these notebooks as they watch the video.
Stars Move Robert Quimby 2022-06-03 | Pictures recorded over 70 years by the same telescope show stars moving across the sky. Proper motion of the stars shows that the Sun and stars are moving through space. Seasonal parallactic motion shows that the Earth is moving around the Sun. The changes over years to decades are small but observable even to backyard telescopes. Wide-field images at the beginning and end of the video were taken with the Omea 8M all-sky camera at the Mount Laguna Observatory in San Diego County.Telescopic images were taken from the publicly available archives produced from the Oschin Schmidt telescope at Palomar Observatory in San Diego County including the first and second epochs of the Palomar Sky Survey (1950 & 1991), the Palomar Transient Factory (2012-2016), and the Zwicky Transient Facility (2018-2020). Dennis di Cicco's observations were recorded in his backyard using an 11" Celestron and a 16" Meade. I have systematically shifted these points 0.36 arc seconds West and 0.11 arc seconds South.The star with the fastest proper motion is Barnard's Star. According to Gaia, it was located at R.A., Dec. = 17h57m47.667s, +04d44m16.73s on J2015.5, and it is moving 0.8028 arcseconds West and 10.3625 arcseconds North each year with a parallax of 0.547 arcseconds. Watch it move!
The Earth Revolves Robert Quimby 2022-02-07 | Time-lapse of the night sky every 24 hours for a year. Night falls as your location on Earth rotates away from the Sun. At roughly midnight, you see stars in the direction opposite to the Sun. As the Earth revolves around the Sun through the year, the stars visible at midnight change because you are looking in a slightly different direction each night. A year later you are looking (roughly) in the same direction again, and so the same stars are seen once again.This time-lapse video was created from nightly images taken at the Mount Laguna Observatory in San Diego County.
Two clear nights at the Observatory (360° VR Video) Robert Quimby 2021-12-13 | Watch stars, planets, and satellites drift over the Mount Laguna Observatory in east San Diego County for two clear and moonless nights. Images are from an Alcor-System Omea 8M all-sky Camera, which gives a 360°x185° view of the sky. The camera takes 10 second exposures every 15 seconds at night and short exposures every minute of daylight. This time-lapse video was made by showing these images at 30 frames per second.Click and drag the video from your computer, move your phone around, or use a VR headset to immerse yourself in the scene. Most satellites are in low Earth orbit and thus they are only visible for a couple hours after sunset or before sunrise. Higher satellites in medium Earth orbit can be seen throughout the night. Note that satellites can disappear suddenly as they enter Earth's shadow. In contrast, jets fly horizon to horizon, mostly in the same flight paths. Day 10:11 Sun sets in the West0:15 - 0:23 satellites in low Earth orbit streak overhead0:39 geostationary satellite flares in the South (above and left of bright Jupiter)1:17 satellites in low Earth orbit overhead 1:23 dawn breaks in the EastDay 21:36 clouds form to the West1:50 second sunset in the West1:54 - 2:03 satellites in low Earth orbit streak overhead1:59 owl perched to the West2:18 geostationary satellite flares in the South (above and left of bright Jupiter)2:56 satellites in low Earth orbit overhead 3:04 second dawnbreak
Zodiacal Light Robert Quimby 2021-12-09 | Interplanetary dust reflects sunlight back to Earth, creating a band of light that can most easily be seen before dawn or after dusk. This video uses images from the all-sky camera at the Mount Laguna Observatory to show the zodiacal light and how you can observe it yourself from anywhere dark enough to see the milky way. Petr Horálek's image of the zodiacal light is available from ESO: eso.org/public/images/potw1707aNASA's video on the Juno spacecraft's discovery that Mars maybe responsible for this interplanetary dust is here: youtu.be/ve0jLXEzFXE
City Lights Robert Quimby 2021-09-27 | (View on a large screen!). There is no denying how pretty city lights are when viewed from a hill, but they do hide the natural beauty of the stars above. Compare the views from Mt. San Miguel (13 miles / 21 kilometers from downtown San Diego) with the stars shining over the darker skies at Mount Laguna Observatory (44 miles / 70 kilometers from downtown San Diego).Some light illuminating the cities reflects off the atmosphere to produce a sky glow that washes out the stars. Communities like Julian and Borrego Springs have adopted good lighting policies that help keep the skies (and the skies above the Mount Laguna Observatory) dark and allow the stars to shine through. To learn more about preserving the night sky, visit: darksky.orgThis video was made using images from the HPWREN cameras mounted on communications towers on Mt. San Miguel and at Mount Laguna Observatory. Each site has four cameras pointing in the cardinal directions which I have combined to produce the panning effect. The careful viewer will notice that when switching views between Mt. San Miguel and Mount Laguna there is a slight discrepancy in the positions of the stars. This is a result of the 31 mile (50 kilometer) separation of the two sites in longitude: the stars rise and set two minutes earlier at the more easterly Mount Laguna Observatory. For the full version of Ray Price's, "City Lights," visit: youtube.com/watch?v=KH2zrXiWUio
2021 Perseid Meteor Shower Highlights Robert Quimby 2021-09-03 | The peak of the 2021 Perseid meteor shower as seen with the all-sky camera at the Mount Laguna Observatory. Select frames highlight the brightest meteors to strike over two nights.
Moon in Flight Robert Quimby 2021-08-11 | Time-lapse of the Moon rising, setting, dancing with the Sun, and more.Images in this video were taken by the HPWREN cameras as well as the all-sky camera at the Mount Laguna Observatory in East San Diego County.
Great Conjunction of Jupiter and Saturn (2020) Robert Quimby 2021-02-10 | Time-lapse video capturing 6 months of Jupiter and Saturn as they dance among the stars including their closest approach in 400 years on December 21, 2020 (and the closest visible in the last 800 years)
