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Minor Planet 8474 Rettig from Roger Groom on Vimeo.

Video sequence of the minor planet 8474 Rettig moving across the night sky.

I often participate in astronomical research by way of providing observations to other amateurs and to professionals. The promise is always there of credit for the observations but rarely has it actually eventuate in to anything published with my name on it. Here’s one from recently I’m happy to be involved in and credited for my participation (which was a small but useful contribution):

See it on CBAT

Electronic Telegram No. 4122
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director: Daniel W. E. Green; Hoffman Lab 209; Harvard University;
20 Oxford St.; Cambridge, MA 02138; U.S.A.
e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network
(8474) RETTIG
V. Chiorny, Kharkiv Observatory; V. Benishek, Belgrade Astronomical
Observatory, Serbia; P. Pravec and P. Kusnirak, Ondrejov Observatory;
Yu. N. Krugly, Kharkiv Observatory; J. Oey and R. Groom, Blue Mountains
Observatory, Leura, NSW, Australia; V. Reddy, Planetary Science Institute;
D. Pray, Sugarloaf Mountain Observatory, South Deerfield, MA, U.S.A.;
W. Cooney and J. Gross, Sonoita Research Observatory, Sonoita, AZ, U.S.A.;
D. Terrell, Southwest Research Institute; R. Inasaridze, V. Ayvazian and
V. Zhuzhanidze, Abastumani Observatory; R. Montaigut and A. Leroy, OPERA
Observatory, France; and I. Molotov, Keldysh Institute of Applied
Mathematics, Moscow, report that photometric observations obtained during
May 19-July 23 reveal that minor planet (8474) is a binary system with an
orbital period of 30.54 +/- 0.01 hr. Mutual eclipse/occultation events
that are 0.60- to 0.93-magnitude deep indicate a lower limit on the
secondary-to-primary mean-diameter ratio of 0.86. Rotations of the
components appear to be synchronous with the orbital motion and an
amplitude of the combined primary plus secondary rotational lightcurve is
0.34 mag at solar phases 7-15 deg.

NOTE: These ‘Central Bureau Electronic Telegrams’ are sometimes
superseded by text appearing later in the printed IAU Circulars.

(C) Copyright 2015 CBAT
2015 July 26 (CBET 4122) Daniel W. E. Green

Lake Ballard is a salt lake in the Goldfields region of Western Australia. The salt lake is home to an art installation by Antony Gormley know as Inside Australia. This combination of remote salt lake, sculptures and interesting landforms makes Lake Ballard a popular destination for photographers, amateur astronomers, astrophotographers and those simply interested in camping.

Camping facilities at the site are basic but present – long drop toilet, water tank and parking areas where tents and caravans can be set up.

I have been to Lake Ballard on two occasions and both have shown very different sides to what Lake Ballard can be. On the first the salt lake was quite dry and crusty, with a thick white crust which was quite easy to walk on. The second visit over two years later was much wetter, with no solid salt crust and only mud which was very problematic to walk in. You never know quite what you will find when you arrive and exactly what condition the lake and surrounding area will be in.

Love these tufty little plants around the edge of salt lakes like Lake Ballard in Western Australia. At different times of year their colours can be so varied and vibrant.

 

Recently I have been conbritubting many hours of photography to the global effort of documenting and characterizing the comet C/2013 A1 (Siding Spring). This comet will be passing very close to Mars in October. Observations of this comet are useful to agencies such as NASA who have hardware orbiting Mars. Today I published a fun little video of images from just one night, the 24th August. You can see it at Vimeo below.

More of info and pictures of C/2013 A1 (Siding Spring) – click here.

Comet C2013 A1 Siding Spring from Roger Groom on Vimeo.

I bet you thought that you saw everything in that last Karri Forest fungus photo in my previous post, but I bet you didn’t see these little fellow calling out to you, waving his antenna trying to get your attention! 🙂

This photo is taken from John Forrest National Park in the hills of Perth, looking over the Swan Coastal Plain towards Perth. Rain is crossing over the city with dark clouds above.

I seem to be on a “golden sunset” theme at the moment! This time, Geordie Bay on Rottnest Island. It didn’t take any thinking to compose this one, the writing was “on the wall” as soon as I parked my bike and looked up. PS the photo is straight from the camera (on holiday with only camera + iPad).

Aurora Australis from Perth Western Australia, so faint it wasn’t visible out in the field visually or distinguishable on the camera, rather only evident as moving pillars of pink flicking between frames on the PC at home. The Aurora Australis occured between 8:15pm and 9pm on the 14th February. The rising moon then started to brighten the sky and wash out the aurora.

Can you hear it ? The rustle of dry grass in the moderate wind, the Bose SoundLink pumping out Pink Floyd tunes, as the sun sets over the WA Wheatbelt.

 

Meanwhile, lurking in the depth of flowers everywhere at Kalbarri National Park….