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DHEB

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Posts posted by DHEB

  1. Good to know that you made it without serious harm. See this little real story in AAVSO's page for SS Cygni:

    Quote

    Dr. Wheatley wrote the next day:

    Chris phoned me at 0700 UT with the news from Hawaii. I got onto XTE and triggered the satellite straightaway. They have an advertised response time of seven hours, so it's possible we'll get onto SS Cyg with 11 hours of the first observer calling Janet. That would be great...I was so excited at the news that I fell off my bike on the way to work - and I'm sitting here covered in cuts and bruises. It's a dangerous business we're engaged in.

    Astronomy is truly dangerous :happy11:

     

    • Like 2
  2. To further illustrate the point of SS Cyg behaving unusually, see below the light curve for the last year. Since late 2019 the star has had a short "mini" outburst, followed by a long broadly peaked one, followed by a long a bright "quiescence". Also, minimum brightness during the quiescent state has become progressively brighter. This is definitely not normal behavior at SS Cyg.

     

    Cyg-SS.png

    • Like 1
  3. Variable star observers have probably noticed the unusual behavior of SS Cyg since the late part of 2019. The saga is getting more interesting as recent observations indicate heightened activity in X-ray. Monitoring of this star in all wavelengths is encouraged.

    From a recent VSNET alert:

    Quote

    SS Cyg: fast variability at the fading part of an outburst

    As posted in ATel, SS Cyg is now brighter than usual in X-rays.
    According to Nicer data that we took, this object shows violent and fast
    variability in X-rays on timescales of seconds.  The X-ray flux becomes
    higher and the fast variability is amplified now.  This may be QPOs (?)
    and UV light curves showed short-term variability with the period of
    less than 10 sec in its past outbursts.  It seems interesting to check
    if it shows rapid variations in the optical band as well.
    The current magnitude is ~10 mag.  Fast photometric observations
    with the exposure time of less than 10 sec are encouraged.
    Filtered observations are preferable.

    Link to ATel #13744: http://www.astronomerstelegram.org/?read=13744

     

    • Like 2
    • Thanks 1
  4. 8 minutes ago, JeremyS said:

    Hello @Scorpion RobMy dome has been is use for 26 years. No problems at all. The only condensation I've had is after I have been sitting in it for a few hours and breath condenses on the surface. But it soon goes. My drive electronics and permanently out there. I have a dew heater on all the time around the C11 corrector plate and on the drive control pad. I take my CCD + laptop in after each session, but I've also got a couple of laptops in there permanently that are connected to my meteor cameras and they have been operating about 6 years.

    Definitely look after equipment, but we have this kit so it can be used and enjoyed, rather than tucked up (I only been known occasionally to take take Tak to bed). Having an obsy is the single most important thing that has affected my observing. To say it was transformational would be an understatement. For anyone that can, I'd say build an obsy, or get a permanent pier and store like @Alan White has just shown us how to do in an exemplary way.

    IMG_0583.jpg.c3115adbac515f57694c89a66ba5d5c8.jpg

    Looks very nice and elegant with that color. But just curious: doesn't it get too hot inside on a sunny summer day?

    • Thanks 1
  5. One key to observe some galaxies from light polluted places is to search for those that have relatively bright and compact cores (apart from those you saw also M63, M94), as opposed to those that are spread and faint throughout (like M101 or M74). The former tolerate magnification better which helps to distinguish them from the background sky.

    • Thanks 1
  6. Interesting star! I am not an expert either, but VSX lists RZ Cep as RRC/BL, that is overtone pulsator with Blazhko effect. The "double" maximum, or "pre-maximum hump" seems to be a consequence from the particular pulsating frequencies of this star.

    See for example:

    Cester, B., and I. Todoran. "The variability of RZ Cephei." Memorie della Societa Astronomica Italiana 47 (1976): 217-228. (Link to harvard database)

    • Like 1
  7. To all variabilists in SGL!

    AAVSO has recently released an alert encouraging variable star observers to begin closer monitoring of the recurrent nova U Sco before its coming next outburst:

    Alert Notice 664: Monitoring recurrent nova U Sco to discover its imminent eruption

    The outburst is expected to occur sometime in the coming 12 months, but can in principle happen any time from now on.

    U Sco is one of the few known recurrent novae, and is the one with the fastest known recurrent time of about a decade. U Sco is normally about mag 18, but can rise up to mag 7.5 during an outburst. The outbursts of this star are known to be quick, both to rise and fade.

    This could be a very interesting project for both visual and photometric observers. For us in northern latitudes this will be a difficult star to observe because Scorpious lies close to the horizon for us, and is best seen amidst the summer twilight. In any case I wish you good observing (and reporting)!

    This is a plot of AAVSO data from last outburst:

    Sco-U_2009-12-01_2010-04-30.png.12a28bc64c65410ec367dfa700b69c39.png

     

    • Like 4
  8. I have had this scope for a year now and can confirm that it is very good for general wide field low power observing. It is a nice all-round telescope and specially well suited for traveling. Chromatic aberration is present and obvious when looking at bright object. With 460 mm FL it is not easy to reach high magnifications required for planets and Moon, but it is not impossible either. I use it for variable star observing and bright DSO's and I am very happy with it. It is excellent quality for the price.

    As for the CA you can see these photos, taken by attaching a DSLR to the scope with the extension tubes supplied:

    Detail of a birch tree (CA almost not existent):

    02_birch-margin.jpg.bdddb0e56e68fbe481ad44a99edf8f3a.jpg

     

    Detail of a roof border (CA noticeable)

    01_roof.jpg.e3a2be3d470ee2e1162915335a75e445.jpg

    • Like 3
  9. I like Geoptik bags very much and, indeed, have two of them. One problem I have witnessed though is that the inner material in both bags is prone to release a lot of red specks that attach electrostatically to whatever is inside. One not nice surprise for me was to find a lot of these specks deposited on the primary mirror of my Newtonian. I resorted to keep vacuum cleaning the interior of the bags often, but I guess a more fundamental solution would be to use a different inner material. I recently wrote to Geoptik a friendly email to tell about this issue but got no response. Sad.

  10. On 08/24/2017 at 01:25, Stub Mandrel said:

    Imaging Sadr this evening. Probably a visual astronomer's biggest nightmare... lit up like a Christmas tree. Believe it or not the computer is displaying a mostly black PHD2 screen at minimum brightness. main light source is my workshop window.

    599e0e9acc5de_GuidedandCooled.thumb.JPG.48dd1f832270155e2dc45c65edf6f96a.JPG

     

    Indeed, it is often a bit of a challenge to share site between visual observers and astrophotographers, one that requires observance of some etiquette.

    • Like 1
  11. 53 minutes ago, michael.h.f.wilkinson said:

    I should make a new "family portrait", but here is the new addition to the binocular collection: a pair of Opticron 16x80 Observation binoculars, next to my trusty Helios Apollo 15x70 HDs.

    IMG_20170614_194559.thumb.jpg.b964335129da2d329a64b8b96dc53efd.jpg

     

    Nice family! I just wonder what is the main reason you got the new ones, as 16x80 is possibly not that a huge step from 15x70. Is the ability to mount them? Just curious :happy11:

  12. 11 minutes ago, DirkSteele said:

     After everyone else at the lodge in Namibia went to sleep I just sat on a sun lounger by the plunge pool and just took in the view. Had my camera with me and took a few shots.

    That's simply stunning. I am left speechless.

    I suddenly feel an urge to visit Namibia :happy10:!

    • Like 1
  13. My humble but never failing SW 200 PDS, mounted on an even humbler but equally faithful EQ5, here shown while cooling at dusk. Image taken last time out in a dark forest, one week ago. Upon close inspection noticed that Cassiopeia made its way into the photo, behind the finderscope :happy11:

     

    20170501_SW200PDS.png

    • Like 6
  14. On 09/01/2016 at 23:35, Stardust Dave said:

    Lots of beautiful equipment and shelters here! 

    No shelter so I usually observe out -Does an artsy dusk photo count?IMG_2789.jpeg

     

    Thats "COMET" at the EP ... Long tail and very hard to locate,

    IMG_0513.jpeg

     

     

     

    Was the line "No cats were hurt during the production of this picture" missing from the footnote? :happy7:

  15. 7 hours ago, johnrt said:

    Here is mine in my back garden where I image from, house to my back and trees to the north. It's a good representation of the sliver of sky that I can see from my unfortunate back garden location. It's about 2/3 years old, so the trees are even bigger now!

    Something is better than nothing :happy10:

    I understand your feelings, as my backyard during the last 5 years has been a pathetic hole to the SE from a balcony. I will soon move to a better place with zenith though :hello2:!

  16. Two sources of joy:

    Left: TS Optics 15x70, 4.4 deg FOV. Large but relatively light, giving many hours of enjoyment since 2010. Mostly for astronomical use as finder/explorer or grab-and-go companion for short excursions. Most often hand-held, but not seldom mounted on photo tripod with an adapter. Newly collimated.

    Right: Nikon Monark 8x42, 6.3 deg FOV. Since 2015 providing hours of joyful birding during daytime, and the occasional grab-and-go nighttime experience. Hand-held only.

     

    IMG_3052.JPG

    • Like 1
  17. Here are my first two, globular clusters M15 (above) and M2 (below), both on 19 September 2015, single exposures, 15 seconds at 800 ISO.

    Nikon D40X, on the primary focus of a Skywatcher 200PDS (200 mm diameter, 1000 mm focal length, f/5) on a EQ5 equatorial mount.

    Just first experiments, I doubt anyone will get too excited about these :icon_biggrin:

    Cheers!

     

    201509192226_M15.jpg

    201509192231_M2.jpg

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