Radio interferometry is the technique used by professional radio astronomers to create a single large radio telescope using multiple smaller antennas. Radio interferometry allows radio astronomers to obtain radio pictures with higher angular resolution, but up until now this technique has been used only in very expensive research instruments….

Compact SPIDER 300A radio telescope has been used to study the partial solar eclipse at 21 cm wavelength, with magnitude 0.89, in Hong Kong on 21st June, 2020. The radio telescope SPIDER 300A was designed and constructed by the PrimaLuceLab company, Italy. Radio flux density time curves (light curve) and a two-dimension mapping of the eclipse are presented in this paper. Standard radio data reduction methods were used to obtain the intensity time curve. We also adopted the semi-pipeline method for the reduction of data to obtain the same results as with the built-in software of the radio telescope SPIDER 300A. The total solar radio flux of the eclipse was found to reduce by maximum 55±5%, while the maximum eclipsed area of the same eclipse is 86.08%.

Our galaxy is an SBbc medium size and mass spiral type. It is only partially visible, since we are inside it; the plane of the disk and the thousands of stars it contains appear to us as a milky white stripe on the celestial vault, called the Milky Way. The Galaxy is composed of a central core, a bulge, a disk and a halo. In particular, the disc contains the spiral arms. The spiral nature of the Milky Way was confirmed through the study of the distribution of the HII regions, consisting mainly of bright nebulae of ionized hydrogen (HII) that form right inside the spiral arms. The spiral arms are regions of active formation of new stars, dominated by young stars, dust and gas.

In this conference paper, we present the development of radio astronomy in Hong Kong in 21 cm wavelength since 2006. We discuss the subtropical region with its usual cloudy condition in Hong Kong for launching radio astronomy. The MIT small radio telescope and Italy SPIDER radio telescope series were good starting points to create radio astronomy for a dense human populated region like Hong Kong. We present some interesting results with respect to these two types of radio telescopes. We also introduce the future possibility for the developing radio interferometry array in Hong Kong for research and teaching.

Cassiopeia A it’s an important object for radio astronomy, a supernova remnant located in Cassiopeia constellation with a flux of 2400 Jansky at 1420 MHz. For this article we used the SPIDER 300A radio telescope that, thanks to the 3 meter parabolic antenna with high precision WP-100 mount, high sensitivity H142-One receiver, and the advanced features of the RadioUniversePRO software, is able to detect Cassiopeia A. The radio telescope is connected to the remote control room by using the Radio over fiber kit for SPIDER radio telescope that removes the normal gain loss because of cable length and improve even more performances of the radio telescope.

The Sun is one of the most interesting radio sources in the sky and solar radio emission can be studied by using SPIDER radio telescopes. The Sun not only emits visible light but also other frequencies in the electromagnetic spectrum, in fact you can feel the Sun heat on our skin, expression of infrared radiation. In this article with step-by-step guide, by using a 3 meter diameter SPIDER 300A radio telescope, we see how to detect radio waves coming from the Sun and generate various results (like radio images and transits) by using the RadioUniversePRO control software. We perform automatic pointing and tracking on the Sun, detection and removal of eventual artificial signal and capture of results.

Taurus A is the radio source in Taurus constellation that corresponds to the Crab Nebula (M1), the supernova remnant exploded on July 4, 1054 and noted by Chinese and Arabian astronomers of the time. Since then, the gas cloud has expanded and today is over 6 light years large. In this article we see how the SPIDER 300A radio telescope “discovered” it by capturing the radio waves emitted by Taurus A and converting them into a radio map, a real photograph in radio waves of this nebula. In fact it is believed that Taurus A emits radio waves for synchrotron radiation caused by electrons in fast spiral motions around magnetic field lines generated by the pulsar inside it. Thanks to the WEB300-5 3 meter diameter antenna and the 1420 MHz H142-One receiver, the SPIDER radio telescope was able to easily record the weak signal and, thanks to the precise mount and pointing system, it generated a radio map with the same technique used by professional radio telescopes.

Is it possible radio astronomy at school? In general, the activities that many schools develop in astronomy are usually made ​​with optical telescopes because instruments for other electromagnetic spectrum bands are considered too expensive or difficult to use. This often translates into single evening visits with students at the public observatories, so you can not conduct a continuous study. Thanks to our SPIDER radio telescopes is now really possible to make radio astronomy at school because, unlike an optical telescope, they can also be used during the day and then during normal lesson time! The SPIDER radio telescope is installed outside and it’s remotely controlled for example from the classroom or the laboratory.

Is it possible to make amateur radio astronomy? If you already have an equatorial mount (the one used with optical telescopes) with at least 50 kg load capacity and Losmandy dovetail clamp (like an EQ8), thanks to the products developed by Radio2Space, you can turn your telescope into an amateur radio telescope, and start your amateur radio astronomy program without the need to have extensive knowledge of radio techniques.