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I've been trying to do some photometry with my DSLR with a view to using it on variable stars as a quick "grab and go" solution when there is a gap in clouds etc.
Rather than looking at variables I decided to start off with comparing some fixed stars to identify how well I can estimate magnitudes with my DSLR, and the table above shows the results.
Using only two stacked frames (5s, ISO 800, F3.5 on my 5DMk2) with no darks, light polluted london sky, and just one comparison star I seem to be able to get to around 1% variance for the majority of the readings, with the worse being 2.54% out. Trying Chi Cas, against Upsilon1, Upsilon2 and omegaAnd comes up with M4.67 which is mag0.03 different (0.55%).
I'll be honest I am surprised at the results as it is not all that far off the 0.01-0.02 mag range often quoted for looking at exoplanet transits for example. Has anyone else tried this exercise as i'm interested to know how these results stack up - good or bad. The only thing I know for sure is I couldn't get it that close visually using my eyes!
By Guy Wells
On March 31, 2018 issue of the Minor Planet Circular, the asteroid previously known as 2001 HQ16 was named.
(72834) Guywells is a Main belt asteroid with a diameter of 3-6 km. It last came to opposition in February 2018 when it reached 18th magnitude. Now it is moving through the constellation Cancer, observable at mag +19.5.
(72834) Guywells was discovered by L Ball, in 2001.
By Guest maryh96
Hi, I am doing an end of degree project on variable stars due next thursday and London's weather does not allow finish it. I was wondering if someone would do me the favour of observing the pulsating variable star V0460 Andromeda http://variablestars.net/stars/460/ in the Johnson R filter, for a period of 1 hour and 50 minutes? please?
Thanks so much!
A GIF animation of 322 x3 second frames showing NEO 3200 Pheathon during its close approach in December last year. It's taken me a while to get around to putting this together...
Frames were taken during the early evening of December 14th 2017 between 18.11.06 UT and 19.44.57 UT as the object crossed the Perseus/ Andromeda border. The field is just under a degree wide. What I think is a sporadic meteor crosses the field about a second in. I could not find a satellite ID for that time and region, nor do I think it is a Geminind as it seem to come from the wrong radiant.
Any comments or observations welcome.
after C/2015 V2 Johnson https://photos.app.goo.gl/yIbgsliYNY047pOl2
and P41/Tuttle-Giacobini-Kresak https://photos.app.goo.gl/FwBAZD4z0cE15dMn2
last year I though I try on C/2017 T1 Heinze. I was hoping for my first comet with a tail. I must say that I am using a Nikon D5100 with a Vivitar S1 3.5@210mm on a NexStar SLT Goto Mount. I am living in Berlin, close to the airport Schönefeld, so high light pollution (not to curse about the neighbors who seem to fear darkness so much that they plastered thier houses with LED lamps). So I used a rough alignment on Deneb, beause it was already below 0°C yesterday 18:00 local time. Then I slewed to Heinze with Stellariums help and got the right direction I guess (FOW is 6x4° with the said setup). I used then Astrotortilla to check and re-slew my (wacky) mount to exact the given position. Then I started to do 20s exposures at 800ISO which already gave me red skies and I though a good compromise of tracking and light.
I was expecting at least a fuzzy spot but nothing. Rechecked the coordinates with calsky.org and today with theskylive.com
It should have been there I guess. But I cant exclude some stupid errors from me. I used also DSS Live Stacker to get a better idea how it would turn out, and also after stacking I got nothing.
Maybe it is one of the star-like pixels in center but how do I check? Stellarium does not show enough stars, I tried DS9 but this crashes so often on me. Maybe I can load some star chart/image and compare it with my astrometry.net solved FITS with embedded coordinates?
Maybe I also could not get enough light, or the comet is to small for my apreture? May I was hoping too much after the tellings about the magnitude?