The Wok the Hydrogen (WOK) radio telescope supplies 24 inches (61 centimeters) of aperture and occurs to be the right form for capturing the 21-cm radio emissions of impartial hydrogen. Credit score: Fung et al. (https://arxiv.org/pdf/2309.15163.pdf)
Wish to discover the celebrities however can’t because of closely light-polluted skies? A workforce of astronomers based mostly at Hong Kong College of Science and Expertise has an answer for you. As an alternative of attempting to seize seen gentle, they counsel going for radio waves – and so they’ve outlined a very fascinating option to do it.
With a home-built setup consisting of low-cost electronics and a easy kitchen wok, you may seize actual astronomical information, measuring the pace of impartial hydrogen current all through our Milky Way. And if you happen to’re fortunate, you may even gather proof of dark matter, too.
A paper detailing the design and capabilities of the DIY radio telescope was lately submitted to the preprint web site arXiv.org,
Discover the sky in radio waves
Radio telescopes, invented within the first few a long time of the twentieth century, have many benefits over conventional optical telescopes. For one, radio telescopes require far much less precision, are simpler, and so they don’t require costly optics.
An honest hobbyist telescope constructed for observing visible gentle could value someplace within the ballpark of $1,000 {dollars}. In the meantime, radio telescopes are far inexpensive as a result of they’re principally simply bits of steel bent into helpful shapes.
Moreover, good observations with optical telescopes require clear, non-light-polluted skies situated removed from cities. However an enormous variety of folks stay in cities, usually making novice astronomy the province of the rich and cellular, obtainable solely to these with entry to the darkest of skies.
One other benefit of radio telescopes is that, whereas people definitely will be predisposed for producing numerous radio emissions, these human-made emissions are very totally different from the radio emissions produced by cosmic objects and phenomena. Meaning human-caused radio noise is comparatively straightforward to filter out utilizing easy digital processing strategies, which isn’t at all times the case for visible gentle air pollution.
A singular strategy to yard radio astronomy
The benefits above are the fundamental rationale behind the Wok for Hydrogen (WTH) instrument developed by the astronomers on the Hong Kong College of Science and Expertise, who’re situated in some of the densely populated cities on the planet. The core part of this do-it-yourself radio telescope is a run-of-the-mill kitchen wok.
Whereas different groups have proposed at-home radio astronomy kits utilizing leftover satellite dishes, it seems that woks have simply the appropriate curvature to focus on a selected frequency of radio emissions, proper round 1,420 megahertz (MHz). This additionally occurs to be the frequency of radio waves emitted by impartial hydrogen atoms when their electrons flip their spin orientation.
This so-called 21-cm line is a comparatively feeble sign. However since hydrogen is the dominant factor all through the cosmos, a galaxy just like the Milky Way incorporates copious quantities of impartial hydrogen. Meaning you may relatively simply decide up the sign, even when contending with the plentiful radio noise present in essentially the most congested of cities.
Construct your personal radio telescope
The WTH radio telescope is simple to construct. You begin with a kitchen wok, which serves because the amassing dish. Then you definately take copper wire and bend it in a selected configuration, as detailed within the paper. This copper wire turns into the receiver antenna that’s used to seize the radio waves.
You do should outsource the subsequent two elements, a sign amplifier and a digital processor. However you may simply discover each on-line, and also you shouldn’t must spend greater than $100 on them.
And that’s it. That’s the whole telescope setup. The digital processor can plug into any pc, and there’s free software program obtainable to research the output. The total value of the system is lower than $150, which is about an order of magnitude lower than the price of a comparable optical telescope setup.
Focusing on impartial hydrogen with WTH
The researchers examined the WTH telescope (which they positioned in a plastic tub with wheels for additional mobility) at their college, not removed from the downtown middle of Hong Kong. They pointed the telescope at numerous areas of the sky and confirmed they have been capable of detect the emissions of impartial hydrogen.
Nonetheless, the sign they detected wasn’t precisely at 1,420 MHz. As an alternative, it was shifted to barely larger frequencies. This, the researchers clarify, is attributable to the movement of the closest spiral arm of the Milky Way towards us, which blueshifts the radiation to the next frequency.
By pointing the telescope in several instructions at totally different instances of the 12 months, you can also use your personal WTH setup to measure the motion of impartial hydrogen fuel all through the Milky Way, making it the right undertaking for an astronomy hobbyist or membership.
The researchers additionally level out that if you happen to head away from light-polluted skies, you may obtain one thing even cooler. With sufficient sensitivity, you may measure the movement of impartial hydrogen at totally different depths throughout the Milky Way, which can be utilized to construct a 3D map of the rotation of fuel all through our galaxy.
However take note, that rotation pace needs to be larger than what you’ll anticipate contemplating solely the mixed gravity of all the traditional, light-emitting matter inside our galaxy. And wouldn’t you recognize it, that discrepancy is without doubt one of the key items of proof for the existence of dark matter.
It’s laborious to consider how a lot data we are able to be taught concerning the universe with even essentially the most primary of instruments – together with a easy kitchen wok.
