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(17 September 2020 – Center for Astrophysics | Harvard & Smithsonian) Following extensive observations of stellar winds around cool evolved stars scientists have figured out how planetary nebulae get their mesmerizing shapes.

The findings, published in Science, contradict common consensus, and show that not only are stellar winds aspherical, but they also share similarities with planetary nebulae.

Gallery of stellar winds around cool aging stars, showing a variety of morphologies, including disks, cones, and spirals. The blue color represents material that is coming towards you, red is material that is moving away from you. Image 8, in particular, shows the stellar wind of R Aquilae, which resembles the structure of rose petals. (courtesy: L. Decin, ESO/ALMA)

An international team of astronomers focused their observations on stellar winds—particle flows—around cool red giant stars, also known as asymptotic giant branch (AGB) stars. “AGB stars are cool luminous evolved stars that are in the last stages of evolution just before turning into a planetary nebula,” said Carl Gottlieb, an astronomer at the Center for Astrophysics | Harvard & Smithsonian, and a co-author on the paper. “Through their winds, AGB stars contribute about 85% of the gas and 35% of the dust from stellar sources to the Galactic Interstellar Medium and are the dominant suppliers of pristine building blocks of interstellar material from which planets are ultimately formed.”

Despite being of major interest to astronomers, a large, detailed collection of observational data for the stellar winds surrounding AGB stars—each made using the exact same method—was lacking prior to the study, which resulted in a long-standing scientific misconception: that stellar winds have an overall spherical symmetry. “The lack of such detailed observational data caused us to initially assume that the stellar winds have an overall spherical geometry, much like the stars they surround,” said Gottlieb. “Our new observational data shapes a much different story of individual stars, how they live, and how they die. We now have an unprecedented view of how stars like our Sun will evolve during the last stages of their evolution.”

Observations with the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile revealed something strange: the shape of the stellar winds didn’t conform with scientific consensus. “We noticed these winds are anything but round,” said Professor Leen Decin of KU Leuven University in Belgium, and the lead author on the paper. “Some of them are actually quite similar to planetary nebulae.” The new findings may have a significant impact on calculations of galactic and stellar evolution, most pointedly for the evolution of Sun-like stars. “Our findings change a lot,” said Decin. “Since the complexity of stellar winds was not accounted for in the past, any previous estimate of the mass-loss rate of old stars could be wrong by up to a factor of 10.”

The observations revealed many different shapes, further connecting stellar wind formation to that of planetary nebulae. “The winds we observed exhibit various shapes that are similar to planetary nebulae,” said Gottlieb. “Some are disk-like, while others are shaped like eyes, spiral structures, and even arcs.”

Astronomers quickly realized that the shapes weren’t formed randomly, and that companions—low-mass stars and heavy planets—in the vicinity of the AGB stars were influencing the shapes and patterns. “Just like a spoon that you stir in a cup of coffee with some milk can create a spiral pattern, the companion sucks material towards it as it revolves around the star and shapes the stellar wind,” said Decin. “All of our observations can be explained by the fact that the stars have a companion.”

In addition, the study provides a strong foundation for understanding Sun-like stars and the future of the Sun itself. “In about five billion years, the Sun will become more luminous,” said Gottlieb. “Its radius will expand to a length that is comparable to the current distance between the Sun and Earth, and it will enter the AGB phase.” Decin added, “Jupiter or even Saturn—because they have such a big mass—are going to influence whether the Sun spends its last millennia at the heart of a spiral, a butterfly or any of the other entrancing shapes we see in planetary nebulae today. Our current simulations predict that Jupiter and Saturn will create a weak spiral structure in the wind of the Sun once it is an AGB star.”

About Center for Astrophysics | Harvard & Smithsonian

Headquartered in Cambridge, Mass., the Center for Astrophysics | Harvard & Smithsonian (CfA) is a collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

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Renesas’ Intersil brand 14-Bit, 1-MSPS ADC delivers best-in-class radiation-hardened performance

Renesas Intersil brand 14 Bit 1 MSPS ADC delivers best in class radiation hardened performance

(1 December 2020 – Renesas) Renesas Electronics today announced the industry’s highest performance single-chip 14-Bit, 1-MSPS successive-approximation-register (SAR) analog-to-digital converter (ADC) for radiation-hardened (rad-hard) space applications.

Renesas’ Intersil brand ISL73141SEH delivers best in class dynamic and static performance, including signal-to-noise ratio (SNR), effective number of bits (ENOB), integral non-linearity (INL) and differential non-linearity (DNL). The ADC fully resets after every sample, clearing any errors that result from a single event upset (SEU) due to heavy ion radiation during spaceflight.

The ISL73141SEH is one of the key signal-path building blocks in long duration geosynchronous / geostationary Earth orbit (GEO) communication satellites and manned spacecraft, including lunar space missions. By delivering the industry’s best dynamic and static performance, the new 14-bit ADC accurately captures real-world analog transmissions and converts them for processing in the digital domain. The ISL73141SEH ADC is one of seven ICs, including rad-hard temperature sensor, multiplexer, quad op amp, ADC driver, LDO and voltage reference to form a complete sensor interface signal chain solution that accelerates telemetry, tracking, and control (TT&C) and flight computer system development.

“The ISL73141SEH offers satellite and spacecraft manufacturers the ultimate in ADC performance combined with a best-in-class sensor interface signal chain,” said Philip Chesley, Vice President, Industrial and Communications Business Division at Renesas. “Our space-grade 14-bit ADC delivers significantly better data converter performance than any other competing solution, and it is backed by six decades of leadership in radiation performance testing and characterization that gives spaceflight customers the mission assurance they demand.”

The space-grade ISL73141SEH is fully characterized for enhanced low dose rate-sensitivity (ELDRS) radiation performance up to 75krad(Si) for total ionizing dose (TID) and linear energy transfer (LET) up to 86MeVcm2/mg for single event effects (SEE). The SEE testing also shows no single event latch-up (SEL) or single event burnout (SEB). In addition, single event transients (SETs) have also been mitigated by testing at an LET range up to 86MeVcm2/mg.

Key Features of the ISL73141SEH 14-Bit, 1-MSPS SAR ADC

  • 1-MSPS throughput rate with no data latency and no missing codes
  • 5V supply, dissipates only 60mW
  • High SNR of 82.1dBFS at 5V supply operation
  • Operating from a 3.3V supply at 750-KSPS, dissipates only 28mW
  • Single supply operation simplifies system design
  • Highest dynamic performance of 13.3 ENOB, enabling > 12-bit resolution
  • Superior linearity: ±0.5 LSB INL and ±0.2 LSB DNL
  • Full military temperature range of -55°C to +125°C
  • Sensor Interface Signal Chain for TT&C and Flight Computer

The ISL73141SEH 14-Bit, 1-MSPS SAR ADC is at the heart of the sensor interface signal chain and connects via SPI interface to MPUs, MCUs, and/or FPGAs to digitize sensor signals in digital TT&C subsystems and flight computers. System designers are able to build the entire signal chain with Renesas’ Intersil brand analog and power ICs, including: ISL71590SEH temperature sensor; ISL70444SEH quad op amp; ISL71830SEH 16-channel low voltage multiplexer; ISL70517SEH instrumentation amp with ADC driver; ISL75052SEH high voltage LDO regulator; and ISL71091SEH40 precision, low-noise voltage reference.

Availability

The ISL73141SEH 14-bit, 1-MSPS SAR ADC is available now in a 14-lead ceramic dual flatpack package. An evaluation board is available for evaluating device features and performance.

About Renesas Electronics Corporation

Renesas Electronics Corporation (TSE: 6723) delivers trusted embedded design innovation with complete semiconductor solutions that enable billions of connected, intelligent devices to enhance the way people work and live. A global leader in microcontrollers, analog, power, and SoC products, Renesas provides comprehensive solutions for a broad range of automotive, industrial, infrastructure, and IoT applications that help shape a limitless future.

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BlackSky names Uyen Dinh as Vice President for Government Relations and Strategy

BlackSky names Uyen Dinh as Vice President for Government Relations

(1 December 2020 – BlackSky) BlackSky today announced Uyen (pronounced “Win”) Dinh as its Vice President for Government Relations and Strategy.

Ms. Dinh brings more than two decades of experience, knowledge, and insight in the federal legislative, authorization, and appropriations processes. She is well versed in national security policy, national and military intelligence programs and policies, geospatial intelligence (GEOINT), cybersecurity, and other national security space issues.

Uyen Dinh (courtesy: BlackSky)

“BlackSky will make significant strides with Uyen leading our government relations and strategy efforts,” said Brian O’Toole, BlackSky CEO. “Uyen has the unique ability to view challenges and opportunities strategically, while building tactical roadmaps to address them. We will benefit from her experiences both in the public and private sectors. We look forward to Uyen spearheading our efforts to ensure that decision makers have a better understanding of BlackSky’s capabilities to deliver near real-time, first-to-know insights.”

Before joining BlackSky, Ms. Dinh served in the Department of Homeland Security as Deputy Assistant Secretary for the Office of Legislative Affairs. Prior to her executive branch service, she established Win Strategies, a strategic consulting company specializing in national security, space, ISR, and GEOINT issues. Earlier in her career she served as the vice president for government affairs at GeoEye, Inc., an early New Space company that built and launched high-resolution commercial imaging satellites.

Previously, Ms. Dinh served as majority counsel for several U.S. House of Representative committees and offices including the House Permanent Select Committee on Intelligence (HPSCI), the House Armed Services Committee (HASC), the Committee on Government Reform and Oversight, and the Office of Rep. Tom Davis (R-Va.) specializing in national security and defense, intelligence, and homeland security issues.

“I’m excited about my new role with BlackSky,” said Ms. Dinh. “It’s a dynamic and innovative company with strong leadership and a talented workforce. BlackSky has a clear mission to deliver timely and accurate geospatial intelligence to better inform critical decision making. I’m looking forward to advancing this mission; by bringing awareness to how predictive analytics give decision makers exactly the info they need, when they need it. This is game changing.”

Born in Saigon, the Republic of Viet Nam, Ms. Dinh immigrated with her family to the United States in 1975. She received her undergraduate degree from James Madison University and her Juris Doctor from the Catholic University of America Columbus School of Law. Ms. Dinh is a member of the Virginia State Bar and serves on the Washington Cyber Roundtable’s Board of Advisors.

About BlackSky

BlackSky is a global monitoring company. We monitor activities and facilities worldwide by harnessing the world’s emerging sensor networks and leveraging our own satellite constellation. We process millions of observations daily from space, air, environmental sensors, asset tracking sensors, Industrial IoT, and Internet-enabled narrative sources. BlackSky’s on-demand swarm of satellites can image a location multiple times throughout the day. We monitor for pattern-of-life anomalies to produce alerts and enhance situational awareness. Our monitoring service is powered by cutting-edge compute techniques including machine learning, artificial intelligence, computer vision, and natural language processing. BlackSky’s global monitoring is available via a simple subscription and requires no IT infrastructure or setup.

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ND SatCom unveils SKYWAN 5G Release 2.0

ND SatCom unveils SKYWAN 5G Release 20

(1 December 2020 – ND Satcom) ND SatCom has unveiled SKYWAN 5G Release 2.0, the latest iteration of the only VSAT technology allowing multi-channel TDMA networks with True-Mesh ACM for hubless secure communication.

ND SatCom’s new True-Mesh ACM, provides the highest link reliability and stability regardless of changing link conditions, boosting throughput by throttling only the direct hop between two sites, while also supporting SCPC.

SKYWAN 5G (courtesy: ND Satcom)

SKYWAN 5G Release 2.0 secures mission-critical networks with these major new advantages:

  • Boosted network performance: 64x boost throughput with unique ACM true mesh
    • Industry-leading ACM with single-hop mesh
    • Highest link reliability regardless of weather

  • Enhanced network options: 3x the choice with our triple mode within one modem
    • Flexibly decide network topology

      • Hubless true mesh MF-TDMA, DVB-S2 or SCPC

    • New SCPC links provide highly efficient point-to-point connection

  • Assured investment: 4 years software support for business continuity and cybersecurity
    • Diminish impact from cyber threats
    • Activate security and stability patches whenever
    • Save bandwidth with the smart new “over-the-air” update

“The game changing SKYWAN 5G Release 2.0 is here,” said Michael Weixler, Head of Product Management. “True-Mesh ACM with intelligence integrated into the SKYWAN nodes automatically gives the customer maximum performance for any topology and network design. Combined with the new Point-2-Point waveform on the same platform, customers decide when to re-configure their networks based on actual connectivity needs,“ Weixler continued. “Flexibility and security throughout represent a whole new level for VSATs and a quantum leap for SKYWAN 5G.”

ND SatCom

With more than 30 years of experience in satellite communications, ND SatCom is the world’s leading supplier of satellite-based communications systems and ground stations and supports customers with critical operations anywhere in the world.

Customers in more than 130 countries have chosen ND SatCom as a reliable source for high quality and secure solutions that include turnkey and customized systems. The company’s innovative technologies are used globally by governments, the military, television and radio broadcasting, telecommunications and enterprises.

The company’s core product SKYWAN enables secure, reliable and fast communications for thousands of users daily. With the SKYWAN network solution, ND SatCom connects the IT world with satellite communication and offers fully integrated and optimised solutions for the worldwide availability of online applications.

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