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Everything posted by lukebl

  1. I've had a go at capturing some interesting distant trans-Neptunian objects. These three are well-placed at the moment. The second two are quite easy to capture, but the first was tricky, being pretty dim (mag 19.5) and at a relatively low altitude. All positions were confirmed by Astrometrica. The field of view of the images is 38.6 x 29.1 arcmin. This is 90482 Orcus. Until this week I'd never heard of it. It's similar, but smaller than, Puto with a diameter of 910km. It occupies a similar 247 year orbit but at a different orbital inclination, and even has
  2. I’m afraid that you won’t be able to see them. Their surface magnitude (as opposed to their total magnitude) is so low (barely brighter, possibly even lower, than the daytime sky magnitude) that you won’t see them. I’ve viewed them both before sunset, but opposite the sun and with a darkening sky, and even then they were so faint and diffuse you could barely see them. I’ve seen Sirius in broad daylight, but that’s an intense point source. Now, with them being close to the sun in a bright sky you don’t stand much of a chance. However, feel free to prove me wrong!
  3. Here's a couple of animations of passes of the International Space Station over my garden, on the 22nd and 23rd March. I captured it by hand-tracking the scope using the viewfinder whist simultaneously clicking the shutter. At least with the size of the sensor on the DSLR, there's a fair chance that the target hits the sensor somewhere These are comprised of around 56 frames over a period of about 2 minutes. Omegon RC8 (fl 1624mm), Canon 700d, 1/1000 sec exposures @ ISO 800. Gif manually stacked and created in Photoshop (very time-consuming). At closest approach, the ISS was 467
  4. Here's a fun animation of tonight's pass of the International Space Station over my garden. I captured it by hand-tracking the scope using the viewfinder (no mean feat, particularly when near the zenith) whist simultaneously clicking the shutter. It's a bit blurry and grainy, but it's quite small, the seeing was bad and my hand's not very steady! This is comprised of 56 frames over a period of about 2 minutes. Omegon RC8 (fl 1624mm), Canon 700d, 1/1000 sec exposures @ ISO 800. Gif created in Photoshop At the end of the clip the ISS passes fairly rapidly into the earth's shadow.
  5. I was going to suggest Uranus too, but then I thought that twice during its 84 year orbit, the planet would be ‘side-on’ (can’t remember the terminology) to the sun and its moons could potentially cast a shadow.
  6. I bought mine a couple of years ago, in anticipation of prices going through the roof post-Brexit. I think I'll be proved correct. I'd better shut up now before I stray into dangerous territory!
  7. I started that thread about my struggles with Ritchey Cretien collimation, which vlaiv referred to earlier. I would point out that one significant positive thing about them is that they hold their collimation extremely well, so I’m not sure where you got the idea that they need constant collimation. Despite my trials and tribulations, I have now mastered RC collimation, which is easy once you get the hang of it! I take it on and off the mount frequently when swapping with other scopes, and it never needs re-collimation.
  8. That's interesting. I didn't think anything could deal with LEDs, as they emit light across the spectrum. I thought that any filter which cut out LED light would also cut out starlight.
  9. You are correct. Regrettably, LP filters don't work with LED lights.
  10. I think you can forget about viewing this from northern latitudes. According to the JPL Horizons website, which calculates ephemerides for all solar system objects, on the 21st it’ll be around magnitude 12, but at a declination of 40 deg S, so not visible from Northern Europe. It then rapidly swings north at closest approach, but plummets to around magnitude 20 by the following night.
  11. Great capture. And thank you so much for not putting a music soundtrack on it, as seems to be the trend!
  12. Hi folks. Here's a capture from last night of this earth-crossing asteroid, scheduled to have a very close pass again in 2029. Firstly, apologies for the horrendous gradient on the images. There was some stray light coming from somewhere, and I was sumultaneously enjoying a party via Zoom, and the jovial ambience and wine meant I didn't take it seriously enough! Anyway, as you may know, Apophis was discovered in 2004 and it was briefly thought that it might collide with earth in 2029. It's 370 metres across, so would do a fair bit of damage, but latest calculations show that it'
  13. Hi. It’s definitely a geostationary satellite. True, they are stationary relative to the observer, but moving relative to the stars and a guided mount and camera. There are thousands of them, a few degrees south of the celestial equator when seen from the northern hemisphere. Bit of a pest when imaging, say, the Orion or Horsehead Nebulae.
  14. Well, whatever to do, I'd like to book my place with you! I was lucky enough to be able to travel to Casper, Wyoming, for the 2017 eclipse. The weather was perfect, and I can't wait to see another one. Hopefully the covid crisis will be over, and I'm still alive!
  15. What with the latest successful landing on Mars, I was thinking about the excitement about the discovery of Methane in the Martian atmosphere and it being a possible indicator of organic life. Could someone explain why that’s so exciting when the outer planets are full of the stuff and no-one’s suggesting that, say, Neptune’s methane is a sign of life. And even on earth, methane can apparently be created by chemical or geological processes. What makes Mars’s methane so special? I was probably asleep during that particular lecture....
  16. Thanks for the comments. A bit of a reprocess with the same data.
  17. Hi folks, OK. Not another Orion Nebula. I've not done any DSO imaging for a long while. Looking at my files, the last time I attempted imaging M42 was way back in 2009! This is the result of just 50 minutes of 2 minutes exposures each of HA and Oiii. Perhaps I'm just lazy, but it's so easy to overexpose this one, and I quite like the understated effect. I particularly like the fact that you can see the blue stars of the Trapezium so well, and other subtle details in the core that often got lost with longer exposures. Omegon RC8, Atik 383L+ mono, HA and Oiii filters. Synthet
  18. Impressive. I've always wanted to see or capture the Pup. Not easy at 52 degrees North, but it's at its greatest elongation now so I must try again.
  19. I have for sale my Atik 428ex mono. It's a superb sensitive CCD in excellent condition. I've captured objects down to about mag 20.5 with it. I've decided to sell as it's better suited to imaging with, say, 500-800mm focal length, than the 1600mm than I'm currently using, in terms of arc-secs per pixel.. Boxed and complete with 5 metre USB cable and 1.25cm nosepiece. You will need a 12v DC cable. £430 for quick sale, including first class tracked postage. UK only (I'm in Norfolk). Features Sensor Type CCD - Sony ICX674 – 3MP Horizontal Resolution: 1931 pixels Vertical
  20. I agree, they’re not well matched, but they’re all I have at the moment!
  21. First clear night for weeks last night and, great, binning with the QHY5 works! A quick session on the Horsehead still only had 3 stars in the field of view, but the guide star was bright and guiding seemed very good. I think my focus was a bit off. 15 x 600 sec exposures, RC 8, Atik 428ex, Baader Ha filter.
  22. ...and apparently you can bin the QHY5 too. That's something I didn't realise. So maybe I don't need a new camera after all.
  23. Opps. Sorry, it looks like you can bin the ASI290 2x.
  24. Thanks for the info vlaiv. Unfortunately, I don't think you can bin the ASI290 in PHD.
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