astronomy

76 Articles

Keeping Track Of The Night Sky With Discrete Logic Chips

February 9, 2024 by 11 Comments

As hobbies go, stargazing has a pretty low barrier to entry. All you really need is a pair of Mark 1 eyeballs and maybe a little caffeine to help you stay up late enough. Astronomy, on the other hand, takes quite a bit more equipment, not least of which is a telescope and a way to get it pointed in the right direction at the right time, and to make up for the pesky fact that we’re on a moving, spinning ball of rock.

Yes, most of the equipment needed for real astronomy is commercially available, but [Mitsuru Yamada] decided to go his own way with this homebrew retro-style telescope motor controller. Dubbed MCT-6, the controller teams up with his dual-6502 PERSEUS-9 computer to keep his scope on target. There are a lot of literally moving parts to this build, including the equatorial mount which is made from machined aluminum and powered by a pair of off-the-shelf stepper-powered rotary stages for declination and right ascension. The controller that runs the motors is built completely from discrete 74HCxx logic chips that divide down a 7.0097-MHz crystal oscillator signal to drive the steppers precisely at one revolution per diurnal day. The pulse stream can also be sped up for rapid slewing, to aim the telescope at new targets using a hand controller.

As impressive as all this is, the real star (sorry) of the show here is the fit and finish. In typical [Yamada-san] fashion, the impeccably wire-wrapped mainboard fits in a robust die-cast aluminum case that fits the retro aesthetic of the whole project. The PERSEUS-9 is used mainly as a display and control terminal, running custom software to show where the telescope is pointed and calculate the coordinates of various heavenly bodies. As a bonus, the 40×7 alphanumeric red LED display should be easy on dark-adapted eyes.

Hats off to [Mitsuru Yamada] on another fabulous build. If you haven’t had enough of his build style yet, be sure to check out his PERSEUS-8 or even his foray into the analog world.

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Telescope Rides On 3D Printed Equatorial Table

January 4, 2024 by 25 Comments

In the realm of amateur astronomy, enthusiasts find themselves navigating a cosmos in perpetual motion. Planets revolve around stars, which, in turn, orbit within galaxies. But the axial rotation of the Earth and the fact that its axis is tilted is the thing that tends to get in the way of viewing celestial bodies for any appreciable amount of time.

Amateur astronomy is filled with solutions to problems like these that don’t cost an arm and a leg, though, like this 3D printed equatorial table built by [aeropic]. An equatorial table is a device used to compensate for the Earth’s rotation, enabling telescopes to track celestial objects accurately. It aligns with the Earth’s axis, allowing the telescope to follow the apparent motion of stars and planets across the night sky.

Equatorial tables are specific to a location on the Earth, though, so [aeropic] designed this one to be usable for anyone between around 30° and 50° latitude. An OpenSCAD script generates the parts that are latitude-specific, which can then be 3D printed.

From there, the table is assembled, mounted on ball bearings, and powered by a small stepper motor controlled by an ESP32. The microcontroller allows a telescope, in this case a Newtonian SkyWatcher telescope, to track objects in the sky over long periods of time without any expensive commercially-available mounting systems.

Equatorial tables like these are indispensable for a number of reasons, such as long-exposure astrophotography, time lapse imaging, gathering a large amount of observational detail for scientific purposes, or simply as an educational tool to allow more viewing of objects in the sky and less fussing with the telescope. They’re also comparatively low-cost which is a major key in a hobby whose costs can get high quickly, but not even the telescope needs to be that expensive. A Dobsonian telescope can be put together fairly quickly sometimes using off-the-shelf parts from IKEA.

Radio Emissions Over Sunspots Challenge Models Of Stellar Magnetism

December 1, 2023 by 1 Comment

Sustained radio emissions originating from high over a sunspot are getting researchers thinking in new directions. Unlike solar radio bursts — which typically last only minutes or hours — these have persisted for over a week. They resemble auroral radio emissions observed in planetary magnetospheres and some stars, but seeing them from about 40,000 km above a sunspot is something new. They don’t seem tied to solar flare activity, either.

The signals are thought to be the result of electron cyclotron maser (ECM) emissions, which involves how electrons act in converging geometries of magnetic fields. These prolonged emissions challenge existing models and ideas about how solar and stellar magnetic processes unfold, and understanding it better could lead to a re-evaluation of existing astrophysical models. Perhaps even leading to new insights into the behavior of magnetic fields and energetic particles.

This phenomenon was observed from our very own sun, but it has implications for better understanding distant stellar bodies. Speaking of our sun, did you know it is currently in it’s 25th Solar Cycle? Check out that link for a reminder of the things the awesome power of our local star is actually capable of under the right circumstances.

Fixing Astronomy In The Blink Of An Eye

November 19, 2023 by 37 Comments

If you’ve ever set a telescope up in your backyard, you probably learned how quick any kind of lighting ruins your observation. In fact, a recent study found that every year, about 10% of the stars that were visible the previous year disappear in the mishmash of light scattering through the atmosphere. A company called StealthTransit has a solution: blink the lights in a controlled way. They have an animated video explaining the concept.

The technology, named DarkSkyProtector, assumes there is LED lighting and that the light’s owner (or manufacturer) will put a simple device in line that causes the LED to blink imperceptibly. As you might guess, the telescope — presumably some giant observatory uses a GPS receiver to synchronize and then images only when the LED lights all turn off. That presumes, of course, that you have a significant number of lights under control.

It is hard to imagine every city and home having astronomy-safe lighting. However, we can imagine a university installing a lighting system on its campus to protect night viewing. The system underwent a test in the Caucasus mountains using a 24-inch telescope and was apparently quite successful with a shutter rate of about 150 Hz. We weren’t clear if each LED control module has to have a GPS-disciplined time source, but it seems like you’d have to. However, the post talks about how the bulbs wouldn’t cost more to make than conventional ones, so maybe they don’t have anything fancy in them.

You can see satellites in the day with some tech tricks. Want to check out observatories? Hit the road. Or, get time on a telescope with Skynet University.

An observatory atop a hill

The Ultimate US Astronomy Roadtrip

October 9, 2023 by 10 Comments

Have 73 hours to kill and fancy a 4,609-mile road trip? Then you can check out some of the best observatories in the US (although we would probably recommend taking a couple of weeks rather than cramming the trip into three days, so you can spend at least one night stargazing at each).

Matador Network compiled a list of what they call the top ten US observatories, and published the daunting map you see above. Even if your trip is plagued by cloudy skies, rest assured the destinations will still be worth a visit. From Arizona’s Lowell Observatory, where the evidence Edwin Hubble used to formulate the Big Bang Theory was collected, to the Green Bank National Radio Observatory in West Virginia, home of Earth’s largest fully-steerable radio telescope, each site has incredibly rich history.

All of the observatories are open to the public in some way or another, but some are only accessible a few days per month, so make sure you plan your trip carefully! You may even want to travel with your own homemade telescope, Game Boy astrphotography rig, or, if you’re really dedicated, portable radio telescope.

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Multispectral Imaging Shows Erased Evidence Of Ancient Star Catalogue

September 18, 2023 by 44 Comments

Ancient Greek astronomer Hipparchus worked to accurately catalog and record the coordinates of celestial objects. But while Hipparchus’ Star Catalogue is known to have existed, the document itself is lost to history. Even so, new evidence has come to light thanks to patient work and multispectral imaging.

Hipparchus’ Star Catalogue is the earliest known attempt to record the positions of celestial bodies (predating Claudius Ptolemy’s work in the second century, which scholars believe was probably substantially based on Hipparchus) but direct evidence of the document is slim. Continue reading “Multispectral Imaging Shows Erased Evidence Of Ancient Star Catalogue” →

An All Sky Camera To Watch The Night Sky

July 1, 2023 by 8 Comments

If you have any astronomer friends you’ll soon discover that theirs is a world of specialist high-quality optical equipment far ahead of the everyday tinkerer, and for mere mortals the dream of those amazing deep space images remains out of reach. It’s not completely impossible for the night sky to deliver impressive imagery on a budget though, as [David Schneider] shows us with a Raspberry Pi powered whole sky camera.

The project was born of seeing a meteor and idly wondering whether meteorite landing sites could be triangulated from a network of cameras, something he quickly discovered had already been done with some success. Along the way though he found the allsky camera project, and decided to build his own. This took the form of a Raspberry Pi 3 and a Pi HQ camera with a wide-angle lens mounted pointing skywards under an acrylic dome. It’s not the Hubble Space Telescope by any means, but the results are nevertheless impressive particularly in a timelapse. We wish there were less light pollution where we live so we could try it for ourselves.

Long-term readers may remember that this isn’t the first Pi sky camera we’ve brought you, for example this one is from 2020.

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