Jump to content



  • Posts

  • Joined

  • Last visited

Everything posted by mrjaffa

  1. Missed these replies guys. I was checking the thread in my 'subscribed' section on my iPad and nothing new was showing up. So only just saw these :-( If there are a few of us from the Teesside area, we should try meet up sometime. I know I'd always be grateful of any help with my set up as I've had it well it over a year and only ever took it out once. And I never really fancy taking it out by myself :-)
  2. Hey bud. Just saw this and your PM. I've actually just got myself the Monday off work so I can stay up for this. Was probably going to view from my garden but did maybe think of venturing out. So thanks for the invite! I may well do so. Think I would need a postcode or something as I've no idea where it is though ;-)
  3. Sounds ideal. See if you can get a postcode for me. I could try it myself ;-)
  4. I wanted to go to Wynyard for one of the meetings last year but never did. I may this time round. I emailed a few of them actually asking for advice on where to go. One of them from Durham was even kind enough to invite me to his place where he has dark skies and his own little observatory. I never did though :-/ I'm sure when I was up Clay Bank the other week, as I was leaving someone was in fact setting up their scope. But it was too dark to tell. I really wanted to stop and ask, but could have been awkward if they weren't lol. I've had mine for well over a year and apart from a failed attempt one night in the freezing cold at Wynyard, I've barely used it. Now is probably a perfect time. Dark enough before midnight and not too cold! :-)
  5. Thanks for that! I actually had about 180 credits from years ago when I went to uni and studied IT (but didn't finish) and they've allowed me to transfer those. So I currently have about 200 credits :-)
  6. I completed S282 in June. And am taking Planetary Science (S283?) in October. When you say you did the 'full degree', do you just mean enough points to get a 'OU degree'? I didn't think these modules were part of a specific degree and did wonder once you had enough points for the degree, what you would say your degree was in. For example, people have maths, physics degrees etc. But with these you can pick random modules right so wouldn't have a specific degree.
  7. I've just subscribed to this. Wasn't sure whether to. Took a few days of pondering so glad to read some positive comments here.
  8. Hey bud. Only just saw your post. I drove up Clay Bank the other night just to check it out and it seems pretty good. I didn't take my scope, was just out and about and thought I'd check it out. It's weird how creepy it is though. Not sure I'd want to go by myself lol. You found anywhere reasonable?
  9. Thanks for this guys. I didn't see the obvious. I've done this now and all the numbers look pretty good. Thanks!
  10. Hey guys. I'm trying to answer a few questions around radial velocity and Hubble constant for my studying. I know the rules around doing people's homework, so I'm just looking to be pointed in the right direction. I have data for a Galaxy edge on. Hydrogen balmer line from two stars, one at each end of the Galaxy. So you would expect one to be moving towards us and one away, but both wavelengths have been stretched slightly, but I'm assuming this is because the Galaxy itself is moving away from us. I've worked out their velocities but I am then asked to work out the galaxies recession velocity. This is where I'm stuck. I only have the wavelengths of light emitted from the stars, not the Galaxy itself. So how can I do this? I haven't read anywhere in my text book that I can take the middle value of two stretched wavelengths, in effect cancelling out the rotation of the Galaxy and giving me a value I can use to then calculate the galaxies velocity. But this is the only way I can think of doing it. Anyone have any ideas? Thanks!
  11. Hey Martin, just wanted to say thanks for your help. I don't even think I know how to type that into the calculator to get mtotal. Guess I'm in a little over my head. This is what I ended up with, but no idea if I'm right. (m1 – m2) = - 2.5 log (b1/b2) The ratio of b1 / b2 = 92/8 as we know S2 is only 8% of the combined magnitude = 11.5 So, (m1 – m2) = -2.5 log (11.5) = -2.65 We can then go further and calculate the apparent magnitude of S1 as we know its absolute magnitude to be 4.85 and its distance to be 12.82 pc. m1 = M + 5 log (d/10pc) So, m1 = 4.85 + 5 log (12.82/10pc) = 5.39 magnitude So we now know both apparent magnitudes and can prove 8.01 is in fact correct for S2 if it contributes only 8% to the combined magnitude of 5.25. (m1 – m2) = -2.5 log (b1/b2) So, 5.39 – m2 = -2.65 In other words, 5.39 = -2.65 + m2 m2 = 5.39 + 2.65 = 8.04 magnitude which is close enough to our value of 8.01
  12. My reply didn't seem to post..... I'm very grateful for this, but I'm soooooo lost. I've actually done something completely different with help frm someone else. Here's what I have.... Using Fig 1, the magnitude of S1 and S2 combined is approximately 5.3. So the difference in magnitudes of S1 and S2 is: (m1 – m2) = - 2.5 log (b1/b2) So, 5.3 – m2 = -2.5 log (100/8) = 2.74 magnitude 8.01 magnitude – 2.74 magnitude = 5.27 magnitude
  13. Hey guys. I'm struggling with a question I need practice with. Spent ages on this now and even asked for help from a friend with a first degree in maths and we're still not too sure. Hopefully someone might be able to help.. Here we go. Two stars in a binary system. S1 and S2. Combined light totals abvout 5.3 apparent magnitude. S2, the smaller star has a magnitude of 8.01 and contributes 8% to the combined magnitude. Using (m1 - m2) = -2.5 log (b1/b2), prove that the apparent magnitude of S2 is in fact 8.01.... Any ideas? Thanks a bunch!
  14. Hey guys. I got some great help in a previous post around a question I was struggling with for my first assignment. Now I'm struggling with another for my second assignment. The question asks, what 2 pieces of observational evidence could be used to determine whether a interstellar cloud would fragment into many protostars rather than one large protostar. I've re read the few chapters for fragmentation and can't find the answer. All I could seem to find was if the cloud is big enough it could fragment to produce many protostars. But nowhere does it say it needs to be so big or dense so the answer can't be its radius and density. Any ideas? Thanks!
  15. Thanks for this! I'm struggling to understand if you have this extra ring which is tight and keeping the scope secured how you can still rotate the scope.... *scratches head*
  16. Can you try that link again please? Doesn't appear to be working. Thanks!
  17. Thant doesn't mean a lot to me I'm afraid. I'm guessing you're assuming mine is motorized? Which it isn't. Hopefully in the future. But I opted for this 200p for decent aperture with a decent mount but was at my limits with the budget.
  18. Thanks for the replies guys. And that video is quite useful. I see what was meant now by the tube rings. Would like to try and do that. I have indeed set it up in the kitchen, so have been playing with it in the light. Think I'm getting to grips with it. Geoff, I did research a lot on what to get. And as I said I had used a cheap EQ set up before so knew what I was getting myself into. And I would long term like to do some imaging. The main problem I have really, is finding a good spot to go to. The last place I tried was no good and I keep putting off going out as I just don't know where to go. But that's something I need to resolve myself I guess. As I said, that video seemed really good and I think its part of a 5 series by the same chap so will watch the rest. Thanks!
  19. Thanks for this guys. I've seen many YouTube vids on setting up and alignment but not just on actually using the scope. Could anyone give me some examples of these tube rings? A link or something? Also. What is the home position? Is this something I need to concern myself with. Is it just simply having everything pointed north to begin with?
  20. I took my scope out for the first time a few nights ago and found it rather difficult to use. I have a Skywatcher 200p EQ5 and have only used a very amateur smaller scope previous to that. I wasn't prepared enough which was my first mistake. Was too cold and should really have had a chair and a stool. My main problem at the moment is just using moving the scope about the sky. I first found it very difficult to just find anything in the finder scope. Then once I did find something, I just couldn't reach the adjustment knobs whilst looking through the eye piece. I can loosen the locks and twist the scope so that I can then reach the knobs but when I do that the tube slips a little and will no longer be balanced. When I need to make a large movement I sometimes find it difficult too as the counter piece ends up moving above the scope so I know I'm not doing that correct. Any suggestions?
  21. Thanks for this. The numbers I have are in the same ball park as those quoted but slightly off. For example, I calculated about 800,000 eV released in those first two stages, where as that text says it is about 1,400,000 eV. So now I'm not sure if I need to take a look at this again.... But I think I understand better now about the neutrino and positron. The question asks to estimate energy carried away by neutrinos and state any assumptions made. So I would assume it's about 2% as some of that 800,000 eV carried away by the positron.
  22. Oh dear. Little over my head there. I am way over my head with this. But I'm giving it a go! For fun apparently..... Deadline is Thursday. To reiterate. First part of the question was to work out how much energy is created in the stages where neutrinos are created. So. I took the mass of the original 4 H atoms (I originally only calculated for 2), and then subtract the mass of the 2 Deuteron and 2 Positron as that is what produced at this first part of the PPI. It states the mass of the neutrino is negligible and so does not give its mass..... The difference from the start in mass to the end mass of this first stage is then converted to energy using e=mc2. I've gone over the numbers and I get 843759 eV which seems right..... The next part of the question states the entire chain created 2.67 x 10^7 eV and to estimate the percentage of this energy carried away by the neutrinos.... So. I presume that the 843750 eV created earlier is carried away by the neutrino (but I'm not sure where the positron comes into this). So. 843750 as a percentage of 2.67 x 10^7 is 3.12%..... Which is almost the 2% already mentioned. Ugh....
  23. Right. I've got my numbers right. I was doing something embarrassingly stupid on the calculator which we'll move over ;-) So.... I now have the energy created in those first two stages where 2 neutrinos and 2 positrons are created. I'm also given the total energy created in the question during the ppi chain. So. The energy created in those two first stages subtracted from the overall energy is the answer right? But what about the pesky positrons? And they energy carried away by neutrinos, is that mostly in the form of kinetic energy?.... I need a rest....
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.