Talk

NACAA 2016 saw a presentation on the visual observation of stars in the Magellanic Clouds. This talk follows on from that, focusing on the Luminous Blue Variables, also called the S Doradus stars, and the suspected, or 'candidate’ population. Discussion of their evolutionary status, lightcurves, and fields is continued and updated. Feedback from the American Association of Variable Star Observers show these objects to be among the most important targets to observe. Certainly, they are the most challenging and rewarding.

Observation of the Sun has gained increased interest in recent years because of the availability of specialised telescopes for amateurs to use. Activity on the sun follows an 11 year cycle and we are currently in cycle 24 and heading towards a solar minimum. This talk will examine the various features of the Sun worth viewing, methods used, as well as the highlights of solar cycle 24 and what is to be expected for cycle 25. The presenter will use NASA solar images and those taken by himself from his own observatory.

ESO's Very Large Telescope facility in Chile has played a pivotal role in many recent discoveries. Just four days after I toured the facility in February 2016, it was announced that seven Earth-sized planets orbiting a cool star (TRAPPIST 1) had been discovered. As well as general technical information about the facility, the talk highlights the contribution made by the VLT and explores the workings of the particular scientific instrument that was used.

As the 2018 NACCA will be held in Ballarat, a city with a rich gold mining history, it is appropriate to do a presentation that shows some of the obvious and the more tenuous links between Gold and Astronomy. The presentation will be rich with facts but also be presented in a lighthearted and approachable way.

The Ballarat Municipal Observatory is a unique science resource in Ballarat, Victoria and Australia. Why is this observatory different? Creating bridges to enable everyone to enjoy science opens the path towards understanding, which in turn leads to respect for Science in general and our Planet in particular.

Light emitting diode (LED) technology has brought significant innovation to the lighting industry. The benefits of high efficacy LED street lighting has encouraged government sponsored programs to reduce power consumption, lower maintenance costs, reduce greenhouse gas emission and reduce sky glow. In the case of sky glow and light pollution there are no standardised or quantitative method of measurement. Some controversy such as health aspects as cited by the American Medical Association (AMA) exist around these refit programs. Presented here is the result of a time series
analysis of data from the Suomi/VIIRS satellite from South-East Australia where LED street lights replaced mercury vapour and compact fluorescent lighting. A town in Victoria, Australia, Bendigo is selected as a case study of radiance. Using a simplified inventory of the prior street lighting the total luminous flux of the lighting inventory is compared to the radiance images from Suomi Day/Night Band (DNB) and compared to the expected results of the sky-glow modelling software Illumina. Discussion is focussed on the use of the Suomi/DNB sensor as a detector and as an estimator of light pollution. Using a simplified model of light in the atmosphere this paper suggests the short wavelength spectral component of the LED luminaires remains in the lower atmosphere and that a greater component of this blue spectrum than the original lighting inventory is produced in the wavelength range specified by the AMA as a blue light hazard.

The new director of the RASNZ Occultation Section will lead a discussion on where the section is operating and what is in the works for the coming years.

As technology and software continues to evolve and new opportunitites emerge on how occultation observation results can do new science, it is no longer enough to just record the times of occultations.  Good science can be done with quality light curves and processes are being formalised on the archiving of observed light curves.

This presentation show cases some of the most interesting and scientifically useful occultation opportunities coming up across Australia in the next two years.

Bring along your questions that you are too embaressed to ask on email.  With some of the most experienced observers in the world in the room you are sure to get an answer.