astronomy

79 Articles

Ask Hackaday: What’s A Sun-Like Star?

April 10, 2025 by 19 Comments

Is a bicycle like a motorcycle? Of course, the answer is it is and it isn’t. Saying something is “like” something else presupposes a lot of hidden assumptions. In the category “things with two wheels,” we have a winner. In the category “things that require gasoline,” not so much. We’ve noticed before that news stories about astronomy often talk about “sun-like stars” or “Earth-like planets.” But what does that really mean? [Paul Gilster] had the same questions, if you want to read his opinion about it.

[Paul] mentions that even textbooks can’t agree. He found one that said that Centauri A was “sun-like” while Centauri B was sometimes considered sun-like and other times not. So while Paul was looking at the examples of press releases and trying to make sense of it all, we thought we’d just ask you. What makes a star like our sun? What makes a planet like our planet?

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Tracking Deep-Sky Objects

March 13, 2025 by 2 Comments

Astrophotography, and astronomy in general, takes some fairly specialized tools and a high amount of precision. Setting up the equipment can also take a lot of time, especially for amateurs traveling to various locations with their equipment, so anything that can reduce the amount of time spent looking for objects and increasing the amount of time looking at them is a welcome addition, especially since nights where conditions are ideal for these activities can be rare. [Anton] developed this real-time tracking tool for deep sky objects (DSOs) to keep tabs on most of the interesting things out there a telescope can be pointed at.

[Anton] calls his tool the Nova DSO Altitude Tracker and gets its information from SIMBAD, updating every minute for a given location on the planet. With that location data, the program calculates altitude and azimuth for various objects and also helps the user keep track of other important variables like moon illumination and angle above the horizon. It also allows the user to highlight specific objects of interest, making sure they are front and center throughout the session. Each DSO can be selected from a list to display detailed information about it such as its path, time visible in the sky, and other properties.

To get the program running, essentially all that’s required is a computer capable of running Python and a display of some sort. From there it provides a quick view of the best objects to point one’s telescope or camera at without any guesswork. With all of the code available it shouldn’t be too much of a leap to do other things with the underlying software, either, such as tying it into a tracker of some sort like this DIY telescope tracking device we featured a while back.

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Hackaday Links: February 23, 2025

February 23, 2025 by 7 Comments

Ho-hum — another week, another high-profile bricking. In a move anyone could see coming, Humane has announced that their pricey AI Pin widgets will cease to work in any meaningful way as of noon on February 28. The company made a splash when it launched its wearable assistant in April of 2024, and from an engineering point of view, it was pretty cool. Meant to be worn on one’s shirt, it had a little bit of a Star Trek: The Next Generation comm badge vibe as the primary UI was accessed through tapping the front of the thing. It also had a display that projected information onto your hand, plus the usual array of sensors and cameras which no doubt provided a rich stream of user data. Somehow, though, Humane wasn’t able to make the numbers work out, and as a result they’ll be shutting down their servers at the end of the month, with refunds offered only to users who bought their AI Pins in the last 90 days.

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A Compass That Looks To The Stars

December 17, 2024 by 19 Comments

Although a lot of tools have been digitized and consolidated into our smartphones, from cameras, music players, calendars, alarm clocks, flashlights, and of course phones, perhaps none are as useful as the GPS and navigational capabilities. The major weakness here, though, is that this is a single point of failure. If there’s no cell service, if the battery dies, or you find yourself flying a bomber during World War II then you’re going to need another way to navigate, possibly using something like this Astro Compass.

The compass, as its name implies, also doesn’t rely on using the Earth’s magnetic field since that would have been difficult or impossible inside of an airplane. Instead, it can use various celestial bodies to get a heading. But it’s not quite as simple as pointing it at a star and heading off into the wild blue yonder. First you’ll need to know the current time and date and look those up in a companion chart. The chart lists the global hour angle and the declination for a number of celestial bodies which can be put into the compass. From there the latitude is set and the local hour angle is calculated and set, and then the compass is rotated until the object is sighted. After all of that effort, a compass heading will be shown.

For all its complexity, a tool like this can be indispensable in situations where modern technology fails. While it does rely on precise tabulated astrometric data to be on hand, as long as that’s available it’s almost failsafe, especially compared to a modern smartphone. Of course, you’ll also need a fairly accurate way of timekeeping which can be difficult in some situations.

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Catching The BOAT: Gamma-Ray Bursts And The Brightest Of All Time

September 18, 2024 by 12 Comments

Down here at the bottom of our ocean of air, it’s easy to get complacent about the hazards our universe presents. We feel safe from the dangers of the vacuum of space, where radiation sizzles and rocks whizz around. In the same way that a catfish doesn’t much care what’s going on above the surface of his pond, so too are we content that our atmosphere will deflect, absorb, or incinerate just about anything that space throws our way.

Or will it? We all know that there are things out there in the solar system that are more than capable of wiping us out, and every day holds a non-zero chance that we’ll take the same ride the dinosaurs took 65 million years ago. But if that’s not enough to get you going, now we have to worry about gamma-ray bursts, searing blasts of energy crossing half the universe to arrive here and dump unimaginable amounts of energy on us, enough to not only be measurable by sensitive instruments in space but also to effect systems here on the ground, and in some cases, to physically alter our atmosphere.

Gamma-ray bursts are equal parts fascinating physics and terrifying science fiction. Here’s a look at the science behind them and the engineering that goes into detecting and studying them.

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Tell Time And Predict The Heavens With This Astronomical Timepiece

May 31, 2024 by 2 Comments

Looking for a new project, or just want to admire some serious mechanical intricacy? Check out [illusionmanager]’s Astronomical Clock which not only tells time, but shows the the positions of the planets in our solar system, the times of sunrise and sunset, the phases of the moon, and more — including solar and lunar eclipses.

One might assume that the inside of the Astronomical Clock is stuffed with a considerable number of custom gears, but this is not so. The clock’s workings rely on a series of tabs on movable rings that interact with each other to allow careful positioning of each element. After all, intricate results don’t necessarily require complex gearing. The astrolabe, for example, did its work with only a few moving parts.

The Astronomical Clock’s mechanical elements are driven by a single stepper motor, and the only gear is the one that interfaces the motor shaft to the rest of the device. An ESP32-C3 microcontroller takes care of everything else, and every day it updates the position of each element as well as displaying the correct time on the large dial on the base.

The video below shows the clock in operation. Curious its inner workings? You can see the entire construction process from beginning to end, too.

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The New Extremely Large Telescopes And The US’ Waning Influence In Astronomy

May 13, 2024 by 54 Comments

For many decades, the USA has been at the forefront of astronomy, whether with ground-based telescopes or space-based observatories like Hubble and the JWST. Yet this is now at risk as US astronomers are forced to choose between funding either the Giant Magellan Telescope (GMT) or the Thirty Meter Telescope (TMT) as part of the US Extremely Large Telescope (USELT) program. This rightfully has the presidents of Carnegie Science and Caltech – [Eric D. Isaacs] and [Thomas F. Rosenbaum] respectively – upset, with their opinion piece in the Los Angeles Times going over all the reasons why this funding cut is a terrible idea.

The slow death of US astronomy is perhaps best exemplified by the slow death and eventual collapse of the Arecibo radio telescope. Originally constructed as a Cold War era ICBM detector, it found grateful use by radio astronomers, but saw constant budget cuts and decommissioning threats. After Arecibo’s collapse, it’s now China with its FAST telescope that has mostly taken the limelight. In the case of optical telescopes, the EU’s own ELT is expected to be online in 2028, sited close to the GMT in the Atacama desert. The TMT would be sited in Hawai’i.

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