South African astronomers, together with collaborators from Moscow have discovered Luminous Blue Variable star. A very rare sighting as the star is very old and may soon blow apart causing a supernova explosion, one of the most powerful explosions in the Universe.
Astronomer Dr A. Kniazev from the South African Astronomical Observatory (SAAO), together with collaborators from the Lomonosov Moscow State University Dr V. Gvaramadze and Dr L. Berdnikov, has recently discovered a new example of an incredibly rare kind of star known as a Luminous Blue Variable star (LBV). Out of the billions of stars mapped in our skies, only sixteen confirmed Luminous Blue Variable stars are known to date. The star, named WS1, is the latest addition to this rare group of stars. LBV stars are of interest to astronomers because they are extremely old stars which may soon die and blow apart in a supernova explosion, one of the most powerful explosions in the Universe.
Just like humans, stars do not live forever. Once their fuel has run out they stop shining and die. Stars that are much more massive than the Sun end their lives in powerful supernova explosions which can outshine all the other billions of stars in their galaxy put together. We never know when or where one of these explosions will take place but we can keep an eye on those stars most likely to go supernova in the near future: Luminous Blue Variable stars. Luminous Blue Variables (LBVs) represent a stage in the evolution of very massive stars towards the end of their life. For stars with initial masses of between 20-25 times that of our Sun the LBV stage occurs just before the star dies in a spectacular supernova explosion. For even more massive stars, they pass through the LBV phase slightly earlier in their lifetimes, but those stars too will eventually die in a supernova explosion.
LBV stars are much hotter and therefore more luminous than our Sun. They are some of the most luminous stars known, with brightnesses ranging from 250,000 to 1 million times brighter than our Sun. As a consequence of their high mass they evolve very quickly and have – astronomically speaking – short lifetimes. LBV type stars have a total lifetime of around a few million years and spend much less than one million years in the LBV phase of their evolution. The LBV phase can be thought of as a “stellar retirement” for the most massive stars. The Sun for comparison has a total lifetime of around 9 billion years. Because the LBV phase is so short-lived you have to be incredibly lucky to catch a star at the LBV stage of its life. This explains why they are so rare compared with other types of star.
LBV stars are losing vast amounts of mass as their upper atmosphere streams off into space in a so-called “stellar wind”. These stars undergo random outbursts at their surfaces, spewing their outer atmosphere into space. These outbursts cause variations in their brightness which is one of the key observational signatures of such a star. Another consequence of their immense mass loss is the formation of a bipolar or circular nebula, or cloud, around the star composed of material that has been lost from the star’s atmosphere. These nebulae are found enveloping approximately 70% of confirmed LBV stars. Eta Carinae is a famous and well studied example of a LBV star with a beautiful bipolar nebula.
As most LBVs are enshrouded in a nebula, astronomers often look for possible LBV candidates by searching for such nebulae. In the case of WS1, Kniazev and collaborators were alerted to the possibility that the star could be a LBV because they found in 2011 that it is surrounded by a circular shell of material that emits light at infra-red wavelengths. This prompted them to make follow up optical observations of the central star to confirm whether or not the star was a LBV. In 2011, using the Southern African Large Telescope (SALT) they obtained a spectrum of the star (akin to a fingerprint) and found features in the spectrum typically associated with LBV type stars. However, this information was not sufficient to confirm whether WS1 was indeed a LBV. To do this, astronomers needed to observe the star over a long time period to confirm whether its variability in brightness and in its spectral features matched that expected from a LBV type star. Kniazev and collaborators continued to observe WS1 between 2013 and 2014 using the SALT telescope to look for changes in the star’s spectrum. They also monitored the star’s brightness between 2011 and 2014 using the South African Astronomical Observatory’s 1.9 m telescope and combined their observations with publicly available data spanning over forty years.
By combining the information from all their observations they found that WS1 did indeed exhibit all the observational characteristics of a LBV type star and concluded that WS1 is an incredibly rare Luminous Blue Variable star.
“We were very lucky to discover major spectral and brightness changes in WS1 without having to wait for too long”, says Kniazev. “With this discovery, we unambiguously proved the LBV status of this star. We expect that subsequent spectral analysis will allow us to determine fundamental parameters of WS1, for example its temperature and luminosity. We also hope to find more bona fide LBVs using SALT, which will help us to understand better the evolution of LBV type stars and their relation to other types of massive, old stars.”
This discovery, published as a Letter to Monthly Notices of the Royal Astronomical Society brings the total number of LBV stars known to date to sixteen.
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Cross-channel chat launched
Clickatell has launched a cross-channel live chat service, Touch Go, that transforms omni-channel customer care.
It enables live chat across a company’s website as well as social platforms (Twitter and Facebook) and mobile apps, bringing customer care and engagement into a single business platform.
“Today’s consumers expect to engage with your brand on the digital channel of their choosing,” says Deon van Heerden, Clickatell Engage CEO and Group CFO. “They want to message your business and instantly have queries resolved, find the information and services they are looking for, without the need for a voice call. Clickatell’s Touch Go makes that happen with the right level of capabilities for businesses of all sizes.”
Businesses can start using Touch Go immediately, with a free Starter option. Touch Go requires no credit card for sign-up and is fully featured with a simple setup process. It offers customisable branding, a unified chat desk business application as well as reports and analytics.
As the business scales up its digital customer care, it can opt-in for the Touch Enterprise offering. Touch Enterprise is designed for scaling up customer care efforts through advanced capabilities including AI driven virtual agents, sentiment analysis, automated workflows, enterprise integrations and in-channel mini-applications.
“Customer care has become a defining factor for sustained business success ” says Nirmal Nair, Clickatell Engage EVP Product & Marketing. “In an ever-increasing mobile native world, customers often choose to interact digitally, but they also expect to be able to reach a human immediately, should they need. Monitoring multiple channels and providing immediate action becomes challenging with siloed deployments. Touch’s unified solution allows businesses of all sizes to provide the customer delight in a simple modular approach.”
SA gamers for eWorld Cup
VS Gaming has crowned the winners of the Xbox One and Playstation 4 EA Sports FIFA tournament that saw 1 024 players compete for the right to contest the FIFA eWorld Cup playoffs later this year.
After two grand finals this weekend, Shiaan Rubeer and 16 year old Thabo Moloi were victorious on Xbox One and Playstation 4 respectively. Each player won R400 000 as the first prize on each platform.
“This was an historic moment for efootball in South Africa,” said Wanda Mkhize, spokesperson for VS Gaming. “Through this tournament South African players have now been given the international spotlight that they deserve. This is what it means for VS Gaming – to open new doors of possibility for our players and thereby grow our communities.”
VS Gaming was given the rights to host a FIFA eWorld Cup Qualifier in March after signing an agreement with EA Sports.
“We are proud of what we have been able to achieve this weekend,” said Mkhize. “Over a thousand players competed to take on the worlds best and two of our South Africans will be able to compete on the world stage as a result. We are excited to see what the future holds for this sector.”
The top four players across each platform were:
First place: Shiaan Rugbeer
Second place: Irshaad Mahomed
Third place: Abu Akhalwaya
Fourth place: Khalid Fakie
First place: Thabo Mike Moloi
Second place: Zuhair Ebrahim
Third place: Ziyadh Caasim
Fourth place: Mohammed Fiaz Mahomed
About the VS Gaming Cup
- 1,024 players took part in the tournament
- There were 512 players on Xbox One
- There were 512 players on Playstation 4
- The total prize pool for this year is over R1,5 million with the winner on each platform receiving R400, 000. The breakdown is as follows:
|XBOX WINNERS||PS4 WINNERS||PRIZE POOL||TOTAL|
|1st Place||1st Place||R400 000||R800 000|
|2nd Place||2nd Place||R150 000||R300 000|
|3rd Place||3rd Place||R75 000||R150 000|
|4st Place||4st Place||R30 000||R60 000|
|5th–8th Place||5th–8th Place||R15 000||R120 000|
|9th–16th Place||9th–16th Place||R5 000||R80 000|
|R755 000||R1 510 000|