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Everything posted by MikeP

  1. You mention counterweights, so I assume you are thinking of an equatorial mount. Why not consider a Dobsonian? There are some nice ones available at good prices. My back isn't best and I found that with a Newtonian on an equatorial mount, I was constantly having to rotate the tube so that I could get the focuser in a position that I could look through. Being vertically challenged I also found I needed steps for a 10" scope when it was pointing toward the zenith. Good luck. Mike
  2. I needed 3 weights on my EQ6 but that was with a Moonlite focuser on the back. I've not tried yet with my replacement EQ6-AZ but despite the extension bar that comes as standard, I'd guess I'll need an extra weight. Touch and go I think. Mike
  3. Something like that might suit me too, so I'll be following along. Mike
  4. I think you can use EQASCOM to nudge the star into the centre but you need to make sure your Align Data is cleared - there's a button under Alignment / Sync. Its possible I am wrong but I think that data is a mapping between RA/Dec and the position of the "cogs" within the mount. That is the part that will confuse Alignmaster. The table is only updated when you sync. PhotoGav is correct re taking iterations to get good PA but I've found that even simply using a compass for azimuth and relying on the mount's altitude still being more or less correct from the previous time I used it, just one iteration gets me close. Incidentally, PHD2 has a drift alignment wizard that you could also consider trying (I've not tried yet but it looks interesting). Mike
  5. It is probable that your problem is down to you using CdC and presumably EQASCOM to slew to the star. The instructions say Disable any multi-star approximate alignment controls and connect the telescope mount to the computer. You really need to let Alignmaster control the slewing and Use the handbox of the Goto mount to center the first star in the ocular cross-hairs That way, Alignmaster is aware of where it positioned the scope i.e. it knows the RA and Dec but also knows how much you had to correct it by. It can then construct a slew that corrects the AZ alignment error when you adjust the star back to the centre with the bolts. Likewise for the ALT adjustment with the second star. Hope that helps a bit. Mike
  6. Got rid of the .al My small contribution to imaging. Mike
  7. You may be better served by using one of the free planetarium programs such as Cartes du Ciel or Stellarium. I use a commercial one called SkyMap (there are plenty of others) that lets me adjust the field of view and control which stars are shown by magnitude. For each one, LOTS of information is available. Here is an example from a star chosen at random (it is displayed much more neatly in the program) Information about TYC 665-229-1 Summary Visual magnitude: 7.45 Spectral type: M... Distance: 906 +/- 192 light years Luminosity: 65.5 +/- 30.8 x Sun's luminosity Position information for 02 Sep 2014 07:19:45 JD: 2456902.80538 Apparent RA: 04h 05m 08.44s Apparent Dec: +12° 32' 45.7" Constellation: Taurus Altitude: +44° 23' 40" Azimuth: 223° 4' 5" Hour angle: 2h 0m 0s Rise: 22h 9m 16s Transit: 5h 20m 4s Set: 12h 26m 56s Names and Catalog Numbers Tycho catalog number: TYC 665-229-1 Hipparcos catalog number: HIP 19003 PPM catalog number: PPM 119590 SAO catalog number: SAO 93747 HD catalog number: HD 25605 BD number: BD +12 0547 Star atlas chart numbers Herald-Bobroff Astroatlas: Chart C-54 Millennium Star Atlas: Charts 209-210 (Vol I) Sky Atlas 2000.0: Chart 11 Uranometria 2000: Chart 178, Vol 1 Display Hipparcos record Display Tycho 2 Catalog record Hipparcos Catalog DataHipparcos Catalogue (ESA SP-1200, 1997). Hipparcos Identifier/Proximity Flag Catalog number: HIP 19003 Proximity flag: None Descriptor V magnitude: 7.45 Variability: This star entry is variable at a level of 0.06 to 0.6 mag Source of V mag: Median Hipparcos magnitude (Hp), combined with information on the colour index (either V-I or Bt-Vt), in combination with the luminosity class. Main Mission Astrometric Data Equatorial coordinates (epoch J2000.0, ICRS) Right Ascension: 04h 04m 18.7619s Declination: +12° 30' 26.800" Standard errors of the equatorial coordinates (epoch J1991.25) RA: 0.00090 arcsec Dec: 0.00066 arcsec Parallax information Trigonometric parallax: 0.00360 arcsec Standard error of the parallax: 0.00097 arcsec Proper motion components (epoch J1991.25, ICRS) RA: +0.06066 arcsec/yr Dec: -0.01795 arcsec/yr Standard error in RA: 0.00113 arcsec Standard error in Dec: 0.00081 arcsec Miscellaneous astrometric information Percentage of data rejected (F1): 0% Goodness-of-fit parameter (F2): -0.79 Tycho Photometry and Colour Indices Bt magnitude: 9.938 Standard error in Bt: 0.038 Vt magnitude: 7.672 Standard error in Vt: 0.013 Johnson B-V colour index: 1.913 Standard error: 0.033 Source of B-V value: Determined from the transformed Tycho Bt-Vt data. Cousins' V-I colour index: 2.83 Standard error: 0.05 Source of V-I value: Method O Main Mission Photometry Median magnitude, Hp: 7.4014 Standard error in median magnitude: 0.0046 mag Scatter of Hp observations: 0.020 mag Number of Hp observations: 42 Main Mission Variability Observed magnitude at maximum and minimum luminosities Mag at max, Hp: 7.36 (5th percentile) Mag at min, Hp: 7.42 (95th percentile) Type of variability: Unsolved variable. Entries are classified as "unsolved" if they do not fall into the other variability categories - this class also includes irregular or semi-irregular variables, and possible variables with amplitudes >=0.03 mag. Comments: Variability data for this star, such as periods, amplitudes, reference epochs, etc, compiled from the Hipparcos Hp data, along with associated ground-based data, are given in the table of "unsolved" variables in the Hipparcos Variability Annex. Multiplicity Data Number of components: 1 Reliability of the solution: Suspected non-single, ie possible double or multiple, although no significant or convincing non-single star solution was found. Miscellaneous Comment: This is a "survey" star. HD identifier: HD 25605 DM identifier: BD +12 0547 V-I colour index: 3.08 mag Spectral type: M... Source of spectral type: SIMBAD Return to top Tycho 2 Catalog DataTycho 2 Catalogue (E.Hog et al., 2000). Basic Information Catalog number: TYC 665-229-1 Magnitude: 7.48 (Johnson V mag) B-V colour index: +1.945 mag Equatorial coordinates (epoch J2000.0, ICRS) RA: 04h 04m 18.7615s Dec: +12° 30' 26.801" Proper motion components (epoch J2000.0, ICRS) RA: +0.06033 arcsec/yr Dec: -0.01720 arcsec/yr Parallax and radial velocity information Trigonometric parallax: 0.00360 arcsec Standard error: 0.00097 arcsec Return to top
  8. ClearOutside said clear for me last night too. As I set up in the afternoon it was cloudy and I had to temporarily cover up when a shower passed through - Mrs MikeP thought I was nuts. By 9pm it was clear and stayed that way till I gave up at 1:30 when dew defeated me. Mike
  9. I think yopu have done a magnificent job. You should be very proud of it. Mike
  10. I love the observatory. It looks like a perfect place for a sleep in the sunshine too. Mike
  11. Thank you Hans, I enjoyed both videos. Welcome to SGL Mike
  12. Polar alignment is the process of aligning your mount with the Earth's axis. In principle what you are doing is to point at a star with sideral tracking turned on and observing what happens. If your polar alignment was perfect, the star would remain in the centre of the FOV for ever. If you are not polar aligned, the star will drift away from the centre and the only way to stop this happening is to adjust the altitude and / or azimuth of your mount. The direction and rate of drift indicating the direction and magnitude of the polar alignment error. You are in the southern hemisphere so I'm reluctant to be too precise but if you read the instructions it will tell you to pick a star in one of the area of the sky, observe drift and adjust azimuth and when that has been done use a star in a different part of the sky to adjust altitude. Its done that way because the rate of drift is maximised that way so you don't have to wait as long to see the drift. How you get the stars in your FOV is irrelevent - you can use go to or slew manually. Once you start aligning the mount and recentring the star to see whether your adjustment has had a positive effect, I'm sure you'll be adjusting manually. HTH Mike
  13. What a lovely place and an interesting looking build. Do you need some sort of damp proof membrane on top of the concrete and bricks? Mike
  14. MikeP

    SGL9 Workshops

    Hi Sandra, you will be very welcome at any or all of the sessions. Bring your dob along with you if you want some help getting it collimated. Mike
  15. I've used thick gauge polythene under shiplap a few times when building sheds (moved house quite often) and its never been a problem. I'd be slightly more nervous about the chipboard on top of DPC on the floor but it is probably OK. Mike
  16. Rather than use an inverter, I use a PSU that takes 12V as input and outputs 15, 16, 18, 19, 20, 22 or 24V. I think I bought it from Maplin. I actually have two - I connect them to both to a 60aH leisure battery and run my laptop and a screen with no problems at all. Mike
  17. I use a PSU that takes 12V as input and outputs 15, 16, 18, 19, 20, 22 or 24V. I think I bought it from Maplin. I actually have two - I connect them to both to a 60aH leisure battery and run my laptop and a screen with no problems at all. Mike
  18. Hi Ron, you are very welcome. We only have the larger global sample of astronomers because people such as yourself sign up and contribute. Mike
  19. Hi Claire. Welcome to the form from another West Sussexer. Mike
  20. Why not dig holes under where the blocks are laid out, fill them with concrete. When it goes off, you could put the blocks on top with a bit of mortar to make levelling easier. With a bit of careful measuring you could drive the angle iron down into the holes before you fill them with concrete. Mike PS Looks like Bizbuilder types quicker than me.
  21. Welcome to the forum from a yamyam now resident in Sussex. Mike PS Thomas Hardy eh? Not heard of that one before
  22. I'm impressed Alex - well done. Mike
  23. Oops - thanks Jack. I must have paid for both copies - honest. Seriously, I bought some spectroscopy books and a Star Analyser a couple of years ago and never got going. My interest has been piqued again recently, which is when I discovered I had two copies of your (very useful) book. It never occurred to me you were a member on here. Hope you aren't offended. Mike
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