Connect with us

Featured

SA telescope helps capture cosmic blast

Published

on

A collaboration of telescopes, including a contribution by the Southern African Large Telescope (SALT) in Sutherland, has unveiled a cosmic explosion about 200 times more powerful than a typical supernova.

To prove the record breaking nature of this supernova explosion, crucially, its distance had to be established. This was achieved with spectroscopic observations taken by SALT.

“Upon seeing the spectral signatures from SALT and realising that we had discovered the most powerful supernova yet, I was too excited to sleep the rest of the night,” said Subo Dong, an astronomer and a Youth Qianren Research Professor at the Kavli Institute for Astronomy and Astrophysics (KIAA) at Peking University.

“This impressive result highlights strengths of SALT and the benefits of Chinese-South African collaboration in astronomy, and we are looking forward to strengthening such collaboration in future”, said Petri Vaisanen, head of science operations at SALT.

At its peak intensity the explosion, called ASASSN-15lh, shone with 570 billion times the brightness of the Sun. If that statistic does not impress, consider that this luminosity level is approximately 20 times the entire output of the 100 billion stars comprising our Milky Way galaxy.

As described in a new study published today in Science, ASASSN-15lh is amongst the closest superluminous supernovae ever found, at around 3.8 billion light years away. Given its exceptional brightness and closeness, ASASSN-15lh might offer key clues in unlocking the secrets of this baffling class of celestial detonations.

“ASASSN-15lh is the most powerful supernova discovered in human history,” said Dong, the study lead author. “The explosion’s mechanism and power source remain shrouded in mystery because all known theories meet serious challenges in explaining the immense amount of energy ASASSN-15lh has radiated.”

ASASSN-15lh was first glimpsed in June 2015 by twin telescopes with 14-centimeter diameter lenses in Cerro Tololo, Chile conducting the All Sky Automated Survey for SuperNovae (ASAS-SN), an international collaboration headquartered at The Ohio State University. (Hence ASASSN-15lh’s somewhat menacing moniker.) These two tiny telescopes sweep the skies to detect suddenly appearing objects like ASASSN-15lh that are intrinsically very bright, but are too far away for human observers to notice.

A spectrum taken at the 2.5 meter du Pont telescope in Chile suggested that ASASSN-15lh might indeed be a superluminous supernova.

To know for sure how luminous ASASSN-15lh was, a measurement of its distance was required. This was determined with spectroscopic observations by Dong’s colleague Saurabh Jha of Rutgers University using the Southern African Large Telescope (SALT). “SALT and its queue schedule observing are ideal for rapidly following up transient events like ASASSN-15lh,” explained Jha.

To clear up where exactly ASASSN-15lh is located, as well as numerous other mysteries regarding it and its hyper-kinetic ilk, the research team has been granted valuable time this year on the Hubble Space Telescope. With Hubble, Dong and colleagues will obtain the most detailed views yet of the aftermath of ASASSN-15lh’s stunning explosion. In concert, Jha has continued to use SALT to obtain spectroscopic follow-up observations to analyze the composition and structure of the explosion as it progresses, including making use of special “Director’s discretionary time” awarded to study this unique event. Important insights into the true wellspring of its power should come to light.

One of the best hypotheses is that superluminous supernovae’s stupendous energy comes from highly magnetized, rapidly spinning neutron stars called magnetars, which are the leftover, hyper-compressed cores of massive, exploded stars. But ASASSN-15lh is so luminous that this compelling magnetar scenario falls short of the required energies. Instead, ASASSN-15lh-esque supernovae might be triggered by the demise of incredibly massive stars that go beyond the top tier of masses most astronomers would speculate are even attainable.

“The honest answer is at this point that we do not know what could be the power source for ASASSN-15lh,” said Dong. “ASASSN-15lh may lead to new thinking and new observations of the whole class of superluminous supernova, and we look forward to plenty more of both in the years ahead.”

Featured

Get your passwords in shape

New Year’s resolutions should extend to getting password protection sorted out, writes Carey van Vlaanderen, CEO at ESET Southern Africa.

Published

on

Many of us have entered the new year with a boat load of New Year’s resolutions.  Doing more exercise, fixing unhealthy eating habits and saving more money are all highly respectable goals, but could it be that they don’t go far enough in an era with countless apps and sites that scream for letting them help you reach your personal goals.

Now, you may want to add a few weightier and yet effortless habits on top of those well-worn choices. Here are a handful of tips for ‘exercises’ that will go good for your cyber-fitness.

I won’t pass up on stubborn passwords

Passwords have a bad rap, and deservedly so: they suffer from weaknesses, both in terms of security and convenience, that make them a less-than-ideal method of authentication.  However, much of what the internet offers is independent on your singing up for this or that online service, and the available form of authentication almost universally happens to the username/password combination.

As the keys that open online accounts (not to speak of many devices), passwords are often rightly thought of as the first – alas, often only – line of defence that protects your virtual and real assets from intruders. However, passwords don’t offer much in the way of protection unless, in the first place, they’re strong and unique to each device and account.

But what constitutes a strong password?  A passphrase! Done right, typical passphrases are generally both more secure and more user-friendly than typical passwords. The longer the passphrase and the more words it packs the better, with seven words providing for a solid start. With each extra character (not to mention words), the number of possible combinations rises exponentially, which makes simple brute-force password-cracking attacks far less likely to succeed, if not well-nigh impossible (assuming, of course, that the service in question does not impose limitations on password input length – something that is, sadly, far too common).

Click here to read about making secure passwords by not using dictionary words, using two-factor authentication, and how biometrics are coming to web browsers.

Previous Page1 of 4

Continue Reading

Featured

Code Week prepares 2.3m young Africans for future

By SUNIL GENESS, Director Government Relations & CSR, Global Digital Government, at SAP Africa.

Published

on

On January 6th, 2019, news broke of South African President Cyril Ramaphosa’s plans to announce a new approach to education in his second State of the Nation address, including:

  • A universal roll-out of tablets for all pupils in the country’s 23 700 primary and secondary schools
  • Computer coding and robotics classes for the foundation-phase pupils from grade 1-3 and the
  • Digitisation of the entire curriculum, , including textbooks, workbooks and all teacher support material.

With this, the President has shown South Africa’s response to a global challenge: equipping our youth with the skills they’ll need to survive and thrive in the 21st century digital economy.

Africa’s working-age population will increase to 600 million in 2030 from a base of 370 million in 2010.

In South Africa, unemployment stands at 26.7 percent, but is much more pronounced among youths: 52.2 percent of the country’s 15-24-year-olds are looking for work.

As an organisation deeply invested in South Africa and its future, SAP has developed and implemented a range of initiatives aimed at fostering digital skills development among the country’s youth, including:

AFRICA CODE WEEK

Since its launch in 2015, Africa Code Week has introduced more than 4 million African youth to basic coding.

In 2018, more than 2.3 million youth across 37 countries took part in Africa Code Week.

The digital skills development initiative’s focus on building local capacity for sustainable learning resulted in close to 23 000 teachers being trained in the run-up to the October 2018 events.

Vital to the success of Africa Code Week is the close support it receives from a broad spectrum of public and private sector institutions, including UNESCO YouthMobile, Google, the German Federal Ministry for Economic Cooperation and Development (BMZ), the Cape Town Science Centre, the Camden Education Trust, 28 African governments, over 130 implementing partners and 120 ambassadors across the continent.

SAP’s efforts to drive digital skills development on the African continent forms part of a broader organisational commitment to the UN Sustainable Development Goals, specifically Goal 4 (“Ensure quality and inclusive education for all”)

A core component of Africa Code Week is to encourage female participation in STEM-related skills development activities: in 2018, more than 46% of all Africa Code Week participants were female.

According to Africa Code Week Global Coordinator Sunil Geness, female representation in STEM-related fields among African businesses currently stands at 30%, “requiring powerful public-private partnerships to start turning the tide and creating more equitable opportunities for African youth to contribute to the continent’s economic development and success”.

Click here to read more about the Skills for Africa graduate training programme, and about the LEGO League.

Previous Page1 of 2

Continue Reading

Trending

Copyright © 2018 World Wide Worx