BAS Observer December 2017

2 BAS OBSERVER STUDENT HELPS DISCOVER NEW PLANET From the US comes a story guaranteed to warm the heart of any amateur astronomer. While it’s not uncommon for dedicated amateurs to make discoveries of, for example, comets or supernovae (our own Brendan Downs did just that), it’s not too often that an amateur helps find a Jupiter-like planet and calculates that this type of planet is relatively rare, occurring in 3 per cent of star systems overall. But that is exactly what Armonk, New York high school senior Dominick Rowan did – and, what’s more, his results were accepted for (joint) publication in the Astrophysical Journal. Rowan worked closely with University of Texas astronomer Dr Stefano Meschiari, together with a team of astronomers from the University of California, Santa Cruz, amonst others. The planet orbits a Sun-like star called HD 32 9 63 and was discovered using observations made by the Keck Telescope in Hawaii. ‘The story of our solar system is really the story of Jupiter,’ Meschiari explained. ‘It's important for us to find Jupiter analogs to find other solar systems like ours.’ Meschiari suggested to Rowan that he could undertake a project to calculate how often Jupiter-like planets form, using the sample of more than 1000 stars that the team has probed with the Keck Telescope over the past two decades, in a search for orbiting planets. ‘It was a collaborative process,’ Meschiari said. ‘We went through every dataset – every star – to look at how many “Jupiters” they have, or how many could have been missed.’ They used software previously created by Meschiari, called Systemic . An online version, Systemic Live , is used in astronomy classes at colleges across the USA. A web-based application, it enables students to visualise and manipulate real data from telescopes around the world, to try to find the signatures of extrasolar planets. Rowan explained that ‘the first objective of the study was to detect all the Jupiter analogs in the Keck survey to calculate their frequency. However, after identifying HD 32 9 63b as a new, unpublished Jupiter analog, Dr Meschiari and I worked to constrain the planetary parameters as an additional objective of the research. After detecting a total of eight Jupiter analogs within the datasets, we worked to correct the frequency for detectability. In other words, it was necessary to assess the probability that a Jupiter analog was missed.’ Amongst other honours, Rowan has been selected as a national finalist for the Siemens Competition in Math, Science, and Technology. Awards are one thing, but as Rowan put it, ‘Working with Dr. Meschiari has solidified my interest in astrophysics and extrasolar studies.’ Well done, Dominick Rowan! Darryl Nixon No material may be reproduced from this publication without the written permission of the Brisbane Astronomical Society Inc. © BAS 2017 Cover image: A Hubble Space Telescope image of NGC 5256, a pair of galaxies in its final stage of merging. Initially imaged in 2008, new data make the gas and dust being whirled around inside and outside the pair more visible than ever before. ( Image courtesy of ESA/Hubble, NASA ) Club representatives PRESIDENT Peter Allison Ph: 0488 140 755 Email: president@bas.asn.au VICE-PRESIDENT Stephanie Williams SECRETARY Colin Gale TREASURER Subbarao (Siva) Sivakumar GENERAL COMMITTEE MEMBERS Ken Wishaw, Caroline Williams and Syed Uddin ASTRO-IMAGING OFFICER Tony Surma-Hawes CATERING OFFICER Caroline Williams DEEP SKY OFFICER Stephanie Williams EDUCATION OFFICER Peter Allison EQUIPMENT OFFICERS Cheryl-Ann Tan and Ashley Ruaux FUNDRAISING/GRANTS OFFICER Mike Lewis LIBRARIAN Stephanie Williams LUNAR AND PLANETARY OFFICER Stephanie Williams MEMBERSHIP OFFICER Caroline Williams MERCHANDISE/SALES OFFICER Vacant PUBLICITY OFFICER Tony Surma-Hawes WEBMASTER/FACEBOOK ADMIN Ashley Ruaux and Peter Allison NEWSLETTER EDITOR Darryl Nixon Ph: (07) 3219 3839 Email: darryl@sunsetdigital.com.au Layout and design: Sunset Publishing Services Pty Ltd ABN 90 130 679 791 POSTAL ADDRESS PO Box 15892 City East, QLD 4002 WEBSITE www.bas.asn.au EMAIL info@bas.asn.au An artist’s impression showing the relative sizes and separation of the star HD 32963 and its newly discovered planet. ( Image courtesy of: Stefano Meschiari/McDonald Observatory )