Tag: sun

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"Cloudsonian" – DIRECTV Solar (And Other) Itty Bitty Radio Telescope Setup For Daytime Fun – Part 1: Cheap PoC

Above (and we didn't do this): The Very Large Array antennas dip in formation to observe a target in the southwest sky. Radio telescopes can observe day or night. From https://public.nrao.edu/gallery/the-backs-of-the-vla-dishes/

When we first bought the house, the DIRECTV dish was screwed in tight on the northwest side and we had no intention of ever doing anything with it because everything we want (WXXI) is pumped direct into our digital antenna. That said, you can't do amateur astronomy and own a dish without at some point wondering if you could do some kind of observing with it – which eventually led me to Mike Brown's "Summer project: Build a radio telescope at home" page on making a solar scope on the super-cheap. A long time ago. "I gotta try that," as the saying goes.

The issue was forced this year by my eldest remarking on how the dish wasn't doing any good in the basement by itself. Good point. It's been seven years, but it is an outdoor dish designed for whatever weather conditions Western NY can throw at it, so I decided it was worth a little bit of money to see what might come of trying to, at the least, pick up the Sun with it.

And it works(!), even it we're a loooong ways away from the movie Contact. I present to you our proof-of-concept house "Cloudsonian" – good enough to find the Sun, geosynchronous satellites providing signal, and other stuff we've not yet identified. Also nearly as much fun as a four-year-old can handle for a good 30 minutes.

And, of course, there is nothing new about this – the Itty Bitty Radio Telescope has lots of precedent (and links) and lots of examples (and links). Some relevant links (and links) below:

  1. https://nightsky.jpl.nasa.gov/docs/ibtmanual2.pdf
  2. https://www.gb.nrao.edu/epo/ibt.shtml
  3. https://www.radio-astronomy.org/store/projects/ibt
  4. http://www.stargazing.net/David/radio/itty_bitty_radio_telescope.html
  5. http://arrl.org/files/file/ETP/Radio%20Telescope.pdf
  6. https://www.aoc.nrao.edu/epo/teachers/ittybitty/procedure.html
  7. https://www.opensourceradiotelescopes.org/itty-bitty-radio-telescope/
  8. Whatever else your web search for "Itty Bitty Radio Telescope" might come up with

If you just wanted to try something, had some money lying around, but didn't want to go into any real technical detail, the below and some aim will get you buzzing.

Parts List

  1. The Complete Dish (for us, with a LNB SL5S4NR2-02) – honest to goodness, there was another one out in the trash at a neighbor's house last year and I didn't think to go out late at night and take it. You might find one cheap on craigslist, might just see one on the street, who knows. Parts are also all over ebay. The range for this sized dish is 12.2 to 12.8 (OK, 12.7) GHz, or the entire Ku band of the EM spectrum. You'll find this out if you do broad searches for "other uses for DIRECTV dishes," where some of the most interesting uses are for outdoor cooking.
  2. ($57) Tripod – we went very cheap on first pass, using PVC I had lying around. We had so much fun that I eventually sprung for a proper tripod to make life (and aiming) a bit easier – 3ft Heavy Duty Tripod Mount for Starlink, Antenna, DIRECTV, Ubiquiti (includes 1.66" by 2" diameter Mast) – https://www.amazon.com/gp/product/B0B2213CV7
  3. ($13) Power Supply – you can do this by soldering some connectors together to get enough 9V batteries to do what you need, but, for $14, you can just buy something you don't have to fiddle with – AT&T (Formerly DIRECTV) 21 Volt Power Inserter for All DIRECTV SWM LNBs (PI21) – https://www.amazon.com/gp/product/B005AME7Y8
  4. Satellite Finder – bought two because the first one (orange) didn't work on battery alone, then the second one (blue) ended up being touchy when plugged in. Orange + Power Supply = audible detection.
  5. ($4) Coax Cable – if you don't have a spare – Monoprice RG6 Quad Shield CL2 Coaxial Cable with F Type Connector – 18AWG, 75 Ohm, 6 Feet, Black – https://www.amazon.com/gp/product/B003L1AG72?th=1
Theodore (4), amateur radio astronomer

We had it out for an hour the first time, fighting with the PVC stand to point the dish at the Sun, then at the rough position we knew the DIRECTV satellite to be, then at various other locations just looking for legitimate changes in signal.

The Thrill Is Not (Entirely) Gone…

It comes out intermittently at this point. After the March setup, we used it during the April 8th Total Solar Eclipse this year. Given the ridiculous cloud cover we had in the Rochester area that entire afternoon, our use of the dish to find the exact location of the Sun and point it out to backyard attendees was entirely reasonable.

Poorly framed, poorly focused, but three generations and the rig on the tripod on April 8th.

I'd be remiss in not mentioning the several relevant pages put together by Martin Pepe on the ASRAS website for those looking for some more background (and others in the area who have done the same or much, much better).

A very simple Round 1 is in the bag and we'll see what else we decide to do with the dish or something more involved as another observatory project. Stay tuned (no pun intended).

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Led Astray By (A) Photon – WordPress, Jetpack, and The Perils Of Embedded Clear Sky Charts (And Other)

A re-post from the CNY Observers website (www.cnyo.org).

Greetings fellow astrophiles,

CNYO has been anticipating our first observing session at Beaver Lake for this year, with the first of our two Spring dates (April 23rd) already clouded/snowed out. The forecast for April 30th hadn't looked too much better based on Monday estimates, leaving us to wonder if attendees would be stuck indoors with a lecture instead of outdoors with the rest of the universe.

I woke up early on the 30th to blue skies and a very bright Sun, certainly already exceeding the expectations of the past few days. But what of the afternoon and evening?

As I am prone to do on the day of an observing session, I headed right for the CNYO Cheat Sheet, where one can find the sky conditions for a large part of Central New York in the form of several Clear Sky Charts (CSCs – and, based on the different cloud cover at different locations, even begin to piece together how the skies at your location may change). The morning's CSCs are shown in the image below.

2015april30_photon_before

You will note that the bars to the far left (representing the morning) are not the dark blue squares that would indicate an almost cloud-less sky. As the red text at the bottom notes, sometimes the CSC images from a previous session are still sitting in your browser's cache and, to make sure you're looking at the newest data, you should hit Page Reload. Well, 5 or 10 of those didn't change matters at all. I clicked on the Downtown Syracuse image in order to see what the actual CSC website said about today. An almost perfect band of dark blue – prime observing weather (when the wind is mild, that is).

So, what happened?

The first clue came when I right-clicked on one of the images in order to see just the image in my browser. When you do this, you should see something like: cleardarksky.com/c/SyrcsNYcs0.gif?1

What I saw for the link was the following: i1.wp.com/cleardarksky.com/c/SyrcsNYcs0.gif?1

Something is afoot in Bootes.

A quick google search indicated that the i1.wp.com (which might also be i0.wp.com, i2.wp.com, maybe more) site is, in fact, an image (maybe other) repository for wordpress.com that is supposed to speed up your page downloading process (by being faster than the same image you might load somewhere else) and is called upon, specifically, by Photon – one of the functions built into Jetpack (itself a large suite of plugins for WordPress that very generally make my life much easier by providing Site Stats, Contact Forms, etc.). That said, this is no good for the Clear Sky Chart, as you don't know how many days ago that i1.wp.com image was saved (and it clearly ain't today's!).

To disable this feature (if it was turned on, anyway), go to your WordPress Dashboard and click on Jetpack on the right-hand side.

2015april30_photon_jetback

At present, Photon is the first clickable item at upper left. Click on "Photon" to reveal the following image:

2015april30_photon_deactivate

Click on Deactivate and go back to your Clear Sky Chart-containing page:

2015april30_photon_after

You'll note that the Clear Sky Charts are fixed (revealing an excellent day for Solar and Night Observing) and you'll also see that the NASA/SOHO image is different, the SWPC/NOAA image is different, and event the Wunderground logo is different. Quite the site fix!

If you have the same problem, I hope the above fixes it. If you know of a site running the Clear Sky Chart and it doesn't reflect what you see outside, let the site admin know.

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Some Light Science Reading. The Constellations: Cetus

As first appeared in the October 2010 edition of the Syracuse Astronomical Society newsletter The Astronomical Chronicle (PDF).

Constellation Map generated with Starry Night Pro 6.

There is a region of the Night Sky that is dominated by aquatic creatures. Alternately, if we consider empty space as its own kind of ocean, there are regions where the stars of the Aquatic Constellations appear to undulate at geologic time scales, making the current arrangement of stars effectively motionless to our eyes and those of many generations to come.

Within this Water Region are the Constellations (as listed at wikipedia) Aquarius, Capricornus, Cetus, Delphinus, Eridanus, Hydra, Pisces, and Piscis Austrinus. If we think in terms of seasonal change, this does seem like an oddity of planning. Who would place the Aquatic Constellations in the Night Sky during the late fall and winter, when the temperature in some parts of the Northern Hemisphere (such as at Darling Hill Observatory) might as well be that of interstellar space? Where are the polar bear and penguin Constellations?

Constellation Map generated with Starry Night Pro 6.

The answer to this has less to do with the apparent location of these Constellations in our Night Sky and more to do with the position of the Sun during our daytime sky roughly six months later (the Sun IN Pisces, for instance). When the Sun is in this region of the sky from our terrestrial perspective, the Northern Hemisphere is well into Spring, the time of the rainy season in our and ancient cultures. The image above shows the position of the Sun at noon on April 1, 2011. No joke. If our blue sky were to disappear, we'd have a few seconds to enjoy the daytime Constellations (before we passed out, were cooked by radiation, or froze to death, depending on where the atmosphere went. Fun factoid – Mercury, with no atmosphere to speak of, provides 24-hour Constellation observing!).

This brings us to Cetus, formerly known as a sea monster (indirect evidence for the lack of submarines in ancient Greece?), now increasingly considered to be a whale (perhaps equally terrifying to a small boat far from land in antiquity). Like some misidentified sea monster seen from a dry beach by a hydrophobic observer, Cetus provides a small amount of clear identification and several subtle treats for Earth-locked amateur astronomers that leave quite a bit to the imagination.

Constellation Map generated with Starry Night Pro 6.

One of the patient treats in Cetus is the variable multiple star Mira (Omicron Ceti). As our Observatory Director Ray Dague pointed out at our last Public Viewing session, this star takes its own 331.65 day journey from a 10.1 magnitude star to a 2.0 magnitude star. That is a phenomenal change! It is current at 6.5 magnitude and found in the neck of the beast (above).

M77 image by Hunter Wilson.

As for Messier Objects, those objects one can definitely say they saw on first pass with even moderately-sized binoculars, Cetus is accompanied by only M77, a distant (47 million light years away) barred spiral galaxy (at left, photo by Hunter Wilson). While one distant galaxy is anchored in this part of the sky, this small region is host to tens-of-thousands of invisible objects swimming around our Sun. Cetus is a border Constellation to the Zodiac, those 12 Constellations that mark the path of the Sun and planets from our observing post on Earth. By the way the borders are drawn, Cetus does play host very occasionally to planets and, notably, the objects of the Asteroid Belt. Cetus had the distinction of being the host to 4 Vesta (shown below, photo from the Hubble Space Telescope), the 2nd largest object identified in the Asteroid Belt, during its discovery on 29 March 1807 by Heinrich Wilhelm Olbers.

4 Vesta (Images taken 2007 May 14 and 16). From hubblesite.org.

And then there's stuff we can only imagine seeing without the most powerful scopes in the known universe. Cetus is the host to JKCS 041 (shown below, also in the neck as marked in the opening image. Must be a hungry monster), the current holder of the title as most distant galaxy cluster yet discovered, residing at a boggling distance of 10.2 billion light years from us. Wikipedia hosts a short little movie about this distant cluster HERE.

JKCS 041 (22 Oct 2009) from NASA/CXC/INAF/S.Andreon et al Optical: DSS; ESO/VLT.

Clear skies, Damian

P.S. It has taken all my concentration to not refer to Cetus as a Whale of a Constellation.