Monday, 13 April 2015

First South African Comet Discovery in 35 Years


13 April 2015
First South African Comet Discovery in 35 Years

In the early hours of the 7th April, an un-manned robotic telescope, MASTER-SAAO, situated near Sutherland in the Karoo, discovered a new comet. This is the first comet to be discovered in South Africa since 1978.  The Russian – South African run telescope has been scanning the southern skies since it began operating in late December 2014, looking for “transients” – new objects which appear in the sky for the first time. Since then, over 60 new  objects have been discovered, most of them being erupting or exploding stars. However, the MASTER-SAAO telescope has just discovered its first comet.

Read more about this discovery 

Sunday, 29 March 2015

DSLR Photometry Experiments. 4. How many darks?

When performing photometry on DSLR images, should dark frames be stacked and subtracted from the light frames? If so, how many dark frames should be used, and which stacking method should be employed? This experiment attempts to answer the first question by evaluating the signal-to-noise ratio (SNR) of stars on an image from which different numbers of dark frames have been subtracted.

Working with constellations in DOCdb

Constellations, of course, aren’t “real” objects, but they are a handy way of slicing up the night sky into more manageable chunks.

Having the sky sub-divided in this way immediately suggests an observing project: carefully examine each chunk of sky for anything and everything interesting. This raises the question: when is a particular part of the sky well-placed for observing?

With the recent addition of “constellation place holders” to the DOCdb database, this is now easy to answer, using the DOCdb List Plan option. Here’s the step-by-step guide.

"Nightfall" - the deep-sky observing newsletter

[1] Editorial
[2] News Notes
[8] Three in: Carina by Dave Blane & Auke Slotegraaf
[19] E3 — A curious globular cluster in Chamaeleon by Douglas Bullis
[28] Heartbeat of a Unicorn — Exploring the fascinating but often overlooked constellation of Monoceros by Carol Botha
[31] Birth of a Deep-Sky Marathon — A report from the 2014 Free State Star Party, with guidelines and recommendations for conducting a deep-sky observing marathon by Hannes & Pieter Pieterse
[50] At My Eyepiece — Veteran deep-sky observer Magda Streicher gives us a look at how she observes. by Magda Streicher
[56] Deep-Sky Projects
[57] Photo Gallery
[59] On The Cover
[appendix] Big 5 of the African Sky

Sunday, 15 February 2015

Boyden Observatory in the light pollution glow

Click to Enlarge. 

The Boyden Observatory is not next to the light pollution from "next door neighbours" anymore. It is right in the glow. Not long before the Milky Way will be an image on the screen and not a magnificent object in the Boyden night sky.

"next door neighbours" -  Maselspoort resort and all the owners on the banks of the Modder River.

Earth Observation Group (EOG)

The NGDC Earth Observation Group (EOG) specializes in nighttime observations of lights and combustion sources worldwide. The group started working with DMSP data in 1994 and has produced a time series of annual cloud-free composites of DMSP nighttime lights. EOG's current focus is on nighttime VIIRS data.

Monday, 26 January 2015

15P/Finlay is now a binocular object due to a series outbursts.

Click to Enlarge!

Hot bright news (26 January 2015) Chart date 26 January 2015, 20:30
from Bloemfontein, South Africa.

Source: Comet Chasing in January; Chart: Skytools 3

15P/Finlay is now a binocular object! It brightened by several magnitudes on January 16, on top of a similar episode in mid-December, apparently due to a series outbursts.

Coma Diameter: 3.9'
Earth Distance: 1.4 AU
Sun Distance: 1.1 AU
Elongation:  49°
Tail Position Angle:  65°
Tail Forshortening: 30%
Actual Coma Diameter: 240000 km
DC:  1
Total motion: 3.06 "/min
   RA:  2.71 "/min
   Dec: 1.44 "/min

Sunday, 11 January 2015

C/2014 Q2 (Lovejoy)

Click to enlarge

Comet C/2014 Q2 (Lovejoy) from 11 - 25 January 2015 (21:00) in the South African Night Sky.

Friday, 26 December 2014

Flapping UFO's

In SkyNews (January 2015)
On August 5, 2010, I was out with my telescope observing the night sky from my drive- way in southern Hamilton, Ontario, when I looked up toward the zenith and saw a triangular formation of three bright “orbs” of light moving incredibly fast toward the northern sky. By this time, I had already been observing the night sky for two years and quickly realized the lights were moving too fast and were larger in size and appearance than a satellite. They were also switching positions smoothly and swiftly. My next thought was a meteorite breakup, but there was no trail and no change in luminosity, and these objects persisted at a constant brightness for about 20 seconds before disappearing behind a tree. I could not come up with a plausible explanation.

About eight months later, while walking into The Hamilton Spectator building to attend a meeting of the Hamilton amateur astronomers, I briefly witnessed a similar event in the low eastern sky and still had no explanation. My answer finally came in June 2011. While outside on my driveway observing, I noticed five strange objects moving down the eastern sky. Luckily, I had binoculars with me this time. To my amazement—and embarrassment— I discovered that the strange “ufos” I had told numerous friends and fellow astronomers about were, in fact, Canada geese illuminated just enough by city lights from below to give the geese a strange, almost otherworldly glow, which made it very difficult to see any detail with the unaided eye. I could not hear them flying, and because they were moving about one another in formation, flapping their wings and flying at a fair speed, they gave an eerie appearance that had haunted me for almost a year.

Since then, I have seen Canada geese at night on numerous occasions. however, once I look through my binoculars, I laugh at myself and return to observing. if you witness what at first appears to be a strange triangular formation of alien craft, grab your binoculars, because I would wager that it’s some Canada geese happily on their way. and you can blame light pollution for the interruption.

Kevin Salwach
Hamilton, Ontario

(Het self al saans oor Bloemfontein hierdie wit voĆ«ls - soos bosluisvoĆ«ls gelyk - met my verkyker gesien.  Wonder of hulle die stadsligte vir navigasie gebruik? - Hannes Pieterse)