Space Chat | Somewhere, something incredible is waiting to be known. - General

[QUOTE=Trixil;50414178]can anyone recommend me a good astrophysics book? i've been deeply interested into astronomy for about 5 years now and i've become very knowledgeable about the subject (at least, quite knowledgeable for my age of 13). but now that i know a lot about astronomy i've been wanting to move on to astrophysics and maybe physics in general because i think that i might be interested. i bought a brief history of time and i understood most of it (it was also kind of interesting), but i want a book about astrophysics specifically and how it affects the development of stars, planets, etc. so i was wondering if you people know a good book for someone who wants to begin studying astrophysics?[/QUOTE] Well, there is Astronomy: A Physical Perspective by Marc L. Kutner which is basically exactly what you're asking for. And it's university level (geared towards Physics or Astronomy students).

I tried taking some pics again. [t]https://cdn.discordapp.com/attachments/164786159845638144/190607675145322497/Honeyview_st.MOV_g6_ap10_conv.png[/t] [t]http://techbot.xyz/ShareX/screenshots/2016/06/10/Honeyview_jp.MOV_g5_ap8_conv.png[/t] [t]http://techbot.xyz/ShareX/screenshots/2016/06/10/Honeyview_ma.MOV_g5_ap10_conv.png[/t] mars is like a fucking orange dot :suicide: either I need a new camera or a proper adapter for it.

[QUOTE=Techbot;50487417]pics[/QUOTE] Those are really legit pics. I remember how epic it was seeing Jupiter for the first time in my dads telescope.

So I've got a spare satellite TV dish and LNB lying around, anyone know of any noise sources aside from the sun in the Ku band (~10-12GHz)?

Not sure what frequency its strongest at but I know there is a strong radio galaxy in Cygnus, called Cygnus A. Its at dec +40 44' 02, RA 19h 59m 28s The crab nebula is also one I know you can observe in the Ku band. If you were really into it you could get another antenna setup and make yourself an interferometer, those are more sensitive to small sources. If you can measure the phase and amplitude of the signal you get, it could be possible to do aperture synthesis with the right software (if anything exists publicly that is) Oh I see, if you want to do radio observing you probably need to do it at 1420 MHz, thats the emission line for hydrogen.

I saw the ISS last night. It was really cool. Basically perfect viewing conditions: not many clouds, shortly before sunrise, passing all the way up to 61 degrees above the horizon near me. I was amazed at how bright and obvious it was, I thought I'd have to be straining to find it.

[QUOTE=JohnnyMo1;50685802]I saw the ISS last night. It was really cool. Basically perfect viewing conditions: not many clouds, shortly before sunrise, passing all the way up to 61 degrees above the horizon near me. I was amazed at how bright and obvious it was, I thought I'd have to be straining to find it.[/QUOTE] Also look for the Iridium satellites, they're pretty bright. [editline]13th July 2016[/editline] [QUOTE=mecaguy03;50598152]Not sure what frequency its strongest at but I know there is a strong radio galaxy in Cygnus, called Cygnus A. Its at dec +40 44' 02, RA 19h 59m 28s The crab nebula is also one I know you can observe in the Ku band. If you were really into it you could get another antenna setup and make yourself an interferometer, those are more sensitive to small sources. If you can measure the phase and amplitude of the signal you get, it could be possible to do aperture synthesis with the right software (if anything exists publicly that is) Oh I see, if you want to do radio observing you probably need to do it at 1420 MHz, thats the emission line for hydrogen.[/QUOTE] I've got 17" satellite dishes and LNBs for days, but I don't have a larger 1m sized dish for hydrogen line astronomy. For UHF frequencies (300-3000MHz) a 17" dish will not cut it. I should probably pop open one of these LNBs and figure out if the master oscillator can be run off a GPS Disciplined Oscillator at some point.

Im actually working on my own radio telescope project right now. I have a 1.8 meter dish with a decent beamwidth, and right now I am fabricating a pyramidal horn antenna for 1420 mHz to act as the feed from that. From there im going to use a monopole probe feeding into some amplifiers and then into this RTL-SDR dongle I got. The midband gain from the dish is around 35 dBi which means that this will be signifigantly more sensitive than doing it with a smaller direct tv dish.

[QUOTE=mecaguy03;50706563]Im actually working on my own radio telescope project right now. I have a 1.8 meter dish with a decent beamwidth, and right now I am fabricating a pyramidal horn antenna for 1420 mHz to act as the feed from that. From there im going to use a monopole probe feeding into some amplifiers and then into this RTL-SDR dongle I got. The midband gain from the dish is around 35 dBi which means that this will be signifigantly more sensitive than doing it with a smaller direct tv dish.[/QUOTE] Definitely invest in an Low-Noise Amplifier and some sort of Low-Pass filter at least. The RTLSDR is very easy to overload by strong signals like those coming from, well pretty much anything. Heck putting an active 100base-t ethernet cable within a foot of the plastic-shelled RTLSDR's is enough to overload it. Definitely use one of the metal bodied RTL-SDR Blog or Nooelec brand RTLSDR's with the Temperature Compensated Crystal Oscillator (TCXO), if you can get a low-phase noise version that would be even better. I can't stress the usefulness of a TCXO enough. I'm also working on decoding NOAA weather satellites with an RTLSDR. Heres what I have so far: [t]http://va7eex.ca/wx-up/NOAA-19_MCIR_S55_1467272900.png[/t] A view of the Georgia Straight and Pacific ocean. You can make out Vancouver Island just about.

Yea I have a TCXO one, and the amplifier im gonna get is one that has been used for 21cm radio astronomy projects before. The RTLSDR I have is a RTL2832U R820T2 TCXO. I have heard that the oscillator is more stable with lower temperatures so I might dig out some heat sinks from one of my junk computers and affix it to the case to help with cooling. The amplifier I want is a mini-circuits ZX60-P162LN+, the low pass will probably be a mini circuits VLF-1400+ In the future I think it would be really cool to make an interferometer, and I think it might be possible to make a small one by using multiple cheap celestron SLT mounts connected to a computer. Something like that could also be used for satellite tracking, so I dont know if I would rather use a small dish, a yagi or something like a helical antenna.

Definitely check out what [URL=sbrac.org]SBRAC[/URL] is up to, they just built this [URL=sbrac.orf/files/b205_platform_finished.jpg]receiver[/URL] out if two Ettus B205 SDRs. Their [URL=sbrac.org/files]files[/URL] section is an interesting browse.

The weather satellite receiver now works, I somehow managed to add the duration of the pass to the start time of the pass in my code so the program only started up the moment the satellite disappeared from view... [T]http://va7eex.ca/wx-up/20160715-1841_NOAA-15_S57_HVCT.png[/t] [T]http://va7eex.ca/wx-up/20160716-0652_NOAA-15_N38-hvct-s.png[/t] Looks like it isn't adapting for the full Doppler shift of the pass.

so i explained to my dad after reading "the science behind interstellar" (excellent book by the way) that time completely stops inside the singularity of a black hole due to how infinitesimally small the singularity is that it (i believe) warps spacetime infinitely. and then he started to freak out and went crazy just because of the thought. which got me thinking; how is spacetime capable of being warped so much to a point where it is infinitely small? or in other words: how is spacetime able to be stretched/warped infinitely thin? i understand everything else about the black hole and i understand that gravity can affect time to an unimaginable degree, but i don't understand how gravity can affect time and space this much.

So I read some things about saving money with your amplifiers. Basically it said that if you have a good first stage amp, with a gain of 20-30db and a noise figure at or below 0.6db, you can use really cheap TV amps with NFs of 4db after it and your noise figure will still be pretty now. So the amp I am looking at has a gain of around 20dB at 1.4GHz and a noise figure of ~0.5dB, with a ip3 linearity of 30 dBm at 1GHz, and then after that I am going to use two $5 amps with noise figures of ~4dB for quite a bit of gain. I also found a place called Mouser Electronics that sells amplifier functional blocks in bulk, but they also sell single ones for real cheap. I can get a 20dB amp with a NF of 0.37dB and 20 dBm IP3 for $5 and then replace the crappy chip on an amplifier board with it.

[URL="http://www.sciencealert.com/the-impossible-em-drive-is-about-to-be-tested-in-space"]the em drive is about to be tested in space[/URL]! i am pessimistic about the outcome but i hope to god i will be proven wrong

It would be amazing if it actually works, but it just seems too optimistic to ever be true. Imagine what it would do to space travel. Once they get it up in space, a transport ship between Earth and mars would be very cheap (for space standards) to operate.

No, it wouldn't be very cheap. Because the energy requirements, thrust, and specific impulse are all fucking retarded. The EM drive agitates me. I am skeptical to the point of [I]almost[/I] being willing to toxx clause about its success. SBIR grants from NASA come out in November, which means right after I end my contract period for part-time work (finishing up what I did full time) all the cool stuff NASA needs is up for bidding and proposal :c

Found a broken used meade LX200 fork with working hand controller for $40 fucking bucks, im going to buy it and try to fix it. It sounds like it isnt really damaged much at all, and it should be easy to diagnose since there are full board schematics available online, so I can troubleshoot with just a multimeter. If I can get it working this will be a huge steal since these are really good mounts with a lot of functionality. I already have a goto mount but it supports a measely 10 pounds of gear, which pretty much rules out reflector telescopes of any appreciable size. With a fork of this size I can attach almost anything I want.

I got to visit [url=http://www.nrc-cnrc.gc.ca/eng/solutions/facilities/drao.html]the Dominion Radio Astrophysical Observatory[/url], cool place. [url=http://chime.phas.ubc.ca/]CHIME[/url] is absolutely massive, and will generate 1TB of data a second for several years once its operational.

Anyone else ever get dizzy and feel to vomit everytime you look into the stars? Trying to imagine the unimaginable size, etc.

[QUOTE=The bird Man;51128198]Anyone else ever get dizzy and feel to vomit everytime you look into the stars? Trying to imagine the unimaginable size, etc.[/QUOTE] where i live, i can't see the stars at all at night even the few stars i do see, i can't be 100% sure aren't actually satellites

[QUOTE=The bird Man;51128198]Anyone else ever get dizzy and feel to vomit everytime you look into the stars? Trying to imagine the unimaginable size, etc.[/QUOTE] i do something like this, except it's with the moon instead. everytime i go outside i look at the moon and have a hard time believing that humans landed on that little white thing in the big blue sky that is actually hundreds of thousands of miles away. i think it really illustrates how far we've come as well as our understanding of the universe.

Just added an amplifier to my NOAA satellite receiver, significantly improved low-elevation performance ensued. [t]http://va7eex.ca/wx-up/20161001-1537_NOAA-19_N60_HVCT.png[/t]

thought this is definitely worth sharing here despite it possibly being late [video=youtube;udAL48P5NJU]https://www.youtube.com/watch?v=udAL48P5NJU[/video] :scream:

[QUOTE=Trixil;51143464]thought this is definitely worth sharing here despite it possibly being late [video=youtube;udAL48P5NJU]https://www.youtube.com/watch?v=udAL48P5NJU[/video] :scream:[/QUOTE] initially i wasn't so impressed until i switched the video to 2k resolution hoyl fuck

Someone bought the lx200 mount before me, though later I found a working autoguider for $30, and while its kind of an old one and has a reputation for being frustrating to use, it is one of the lightest autoguiders available on the market which is good for my relatively flimsy goto mount. Im going to buy a cheapo 60mm refractor to act as a guide scope, while I image with my apochromatic camera lens. Then I can say hello to the deep sky. By the way the Sigma 30-300 DG APO is actually a really good lens for astrophotography considering it costs $150 on amazon, and it actually is for all intents and purposes apochromatic. The only optical aberration I have seen in any of my photographs is some coma around the edges.

Reviving thread with another moon shot! [t]https://i.imgur.com/fWRxWPG.jpg[/t]

That's not a moon, that's my left testicle