Affiliation
American Association of Variable Star Observers (AAVSO)
Thu, 10/01/2020 - 20:57

Hi

I am a member of SARA (Society of Amateur Radio Astronomers)and I just builty a super cool and very cheap Radio Telescope designed to detect H-Line radiation from the Milky Way Galaxy

https://www.rtl-sdr.com/cheap-and-easy-hydrogen-line-radio-astronomy-wi…

Would it be profitable to start an AAVSO Radio Astronomy Forum and a way to gather data and share information on the subject?

This is an Example of results from the above very cheap Radio Telescope, Which allows me to "Observe" even when it's overcast..or daytime.

https://www.youtube.com/watch?v=zXGQAEMd2Yo

Pablo Lewin WA6RSV

 

Affiliation
American Association of Variable Star Observers (AAVSO)
Radio Astronomy Forum

Pablo,

I would be interested in this forum.  I've been wondering whether it is possible for an amateur to observe bright variables in the radio part of the spectrum.   Experience from others in radio might help me to decide what the possibilities are.   The forum idea could be useful.  I don't own a telescope but I do own antennas and radios.   Why not see what my technical limitations in the radio are?   I visually observe my bright variables with binoculars.  I want to learn some more about your 1420 Mhz setup and will email you.   Thanks for posting this information.

Rich Glassner GRIB

 

 

 

Affiliation
American Association of Variable Star Observers (AAVSO)
Radio Astronomy Forum

Pablo,

I also built a hydrogen line radio telescope over the Covid shutdown last spring-- instead of a parabolic reflector, I used a small horn antenna (I have a much larger horn constructed, but haven't tried to use it yet.  It looks like I used the same software that you did as well as the same SDR dongle and I did get similar results.

I think that a radio astronomy forum would be a great idea and would try to contribute to it.

Coincidently, I also belong to an astronomy group called SARA (Southeastern Association for Research in Astronomy), which is a consortium of mostly southeastern universities.

Tom

 

Affiliation
American Association of Variable Star Observers (AAVSO)
Radio Astronomy Forum

This is an interesting coincidence! I have recently been thinking about proposing a radio astronomy forum/observing section. Obviously the average amateur doesn't have a radio telescope in their back yard, but it makes sense to have a forum to at least discuss things and share information.

I too was a member of SARA (the amateur group, not the Southeastern group) until a few years ago and was considering rejoining. I wrote a couple of papers for their journal. I became Section Leader of the AAVSO HEN Observing Group earlier this year and significantly updated the website which was seriously out of date. As part of the new website, I included a section on multimessenger astronomy with links to several radio observatories.

I also built a radio telescope receiver a few years ago from some spare parts left over from a Navy contract I was working. It worked functionally, but suffered from poor sensitivity and would have required large antennas to get enough gain.

Anyway, I would be very interested in being involved in any radio astronomy activities thru AAVSO.

Dave

RA Forum

A few cents worth from the AAVSO Solar Section Chair.  I've built two different solar radios in the microwave frequencies 2.8 GHz and 12 GHz looking for flare activity and proxies for sunspot counts. These radios used 90 cm satellite dishes.  Both had severe disruptions because of how close these frequencies are to satellite communication networks and internet routers. 

Other than that, we would be looking at the OH (Hydroxl) frequencies at 1.6 GHz. This would be for comparing the LPV Mira stars that have OH masers, R Aql, W Hyd, etc.  HOWEVER, these are weak signals and would need a dish in the 25 meter size to detect these masers.  There are folks in the SARA group who do have access to these size dishes.  I would point you to the SARA web page:  https://www.radio-astronomy.org for discussion of this sort.  

We do have an active VLF group who contribute their monthly recordings of solar flaring to the Solar Section, if that is of interest then post ideas and requests to the Solar Section forum.  

Rodney

 

Affiliation
American Association of Variable Star Observers (AAVSO)
Sensitivty

I had a different crazy idea that also overlooked the sensitivity issue:

0-3 GHz reciever on heliax to a fast photodiode on the optical scope.

Three problems right away

Expensive, $4000

Poor sensitivity for fast photodiodes. You gain sensitivy and slow response by adding capacitance. Fast photodiodes can see fast laser pulses but not daylight.

A brief literature search for stellar emissions in that band did not turn up much.

So it's on the back burner until I can find a PD that can see 100 photons at 0 to 6 GHz, or I get time on a 30 meter scope.

Ray