header image

[Sign Up Now] to Receive Our FREE Daily SCVTV-SCVNews Digest by E-Mail

Inside
Weather
Santa Clarita CA
Cloudy
Cloudy
48°F
 
Calendar
Today in
S.C.V. History
January 22
1839 - Gov. Juan B. Alvarado gives most of SCV to Mexican Army Lt. Antonio del Valle. [story]
Diseno map


| Thursday, Jan 11, 2018
CSUN Disk StudyA team of NASA scientists that includes CSUN astronomy professor Wladimir Lyra, has discovered evidence that disk patterns, often indicators of the formation of new planets, can form on their own. Image courtesy of NASA.

Peering far out into the universe, astronomers and astrophysicists look for markers — indicators such as patterns in disks of dust — that might indicate the formation of new planets. Recently, however, a team of NASA scientists that includes California State University, Northridge astronomy professor Wladimir Lyra, has discovered evidence that these disk patterns can form on their own, fed by gas and dust, without the presence of planets.

“In 2013, we discovered that there are features we can explain that do not require planets,” said Lyra, who is also an astrophysicist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena. “The hypothesis before that was that if you saw anything out of the ordinary, you attributed that to planets. We showed that the interaction between gas and dust by itself can create rings and arcs. Our hypothesis is now one of the leading contenders.”

Wladimir Lyra

Wladimir Lyra

Alexander Richert, a doctoral student at Penn State University, is the lead author on the new study, which builds on previous simulations created by Lyra and Marc Kuchner, an astrophysicist at NASA’s Goddard Space Flight Center in Maryland. Kuchner presented the findings of the new study on Jan. 11 at the American Astronomical Society meeting in Washington, D.C. The study includes a new factor in disk pattern formation: radiation pressure created by starlight.

“We’re exploring what we think is the leading alternative contender to the planet hypothesis, which is that there’s an instability in the gas and the dust that makes a disk naturally form the patterns,” Kuchner said.

The instability occurs when high-energy ultraviolet starlight strips electrons from clumps of dust grains. Those electrons collide with and heat nearby gas. As the gas warms, pressure increases and traps more dust, which in turn heats more gas. Lyra and his collaborators called the resulting cycle photoelectric instability (PeI). Simulations created by Richert, Lyra and Kuchner show it can eventually create some of the patterns associated with planets.

Exoplanet hunters watch stars for a few key signs that there might be planets in orbit, such as changes in the color and brightness of the starlight. For young stars, which are often surrounded by disks of dust and gas, scientists look for patterns in the debris that might be caused by an orbiting world, such as rings, arcs and spirals.

“Carl Sagan used to say, ‘Extraordinary claims require extraordinary evidence,’” Lyra said. “I feel we are sometimes too quick to jump to the idea that the structures we see are caused by planets. That is what I consider an extraordinary claim. We need to rule out everything else before we claim that.

“For a long time, people were assuming there were planets even though they didn’t see planets,” he continued. “We also observed huge spiral patterns, like you see in galaxies – those beautiful arms. Alex [Richert] showed that those spirals can be reproduced.”

Lyra and Richert began their collaboration in 2013 while Lyra was a postdoctoral scholar at JPL. Later that year, Lyra and Kuchner found that PeI could explain the rings seen in disks. The researchers modeled how radiation pressure and PeI can affect the movement of dust and gas when working in tandem. They found that the way PeI manifests in different patterns also depends on the physical properties of the dust and gas.

The 2013 simulations of PeI explained how dust and gas can interact to create rings and arcs, such as those observed around the star HD 1414569A. By including radiation pressure, the team’s 2017 models show how these two factors can create spirals like the ones observed around the same star.

“We are advancing the goal of turning these observations into probes [for] planets,” Lyra said. “We are also helping to find planets, because we are improving on our theoretical understanding — to finding planets and isolating planet signatures from the noise.

“As with many theories, the way we built it has been incremental. With this paper, we’ve added another layer.”

Lyra, Kuchner and Richert said that next, they hope to factor in other variables in their simulations, such as turbulence and different types of dust and gas, as well as how those factors might contribute to pattern formation around different types of stars.

Lyra noted that one of his graduate students at CSUN is working on these models, exploring what happens when a gas planet interacts with dust.

“This has been very rewarding, because we are [building] a theory from scratch,” Lyra said of the work with his student researchers and NASA colleagues. “Sometimes we find something entirely new. With the rings, it was exactly that.

“In a way, it is a bit like sailing as an explorer,” he said. “Columbus sailed west to reach India, and he found the Americas. It is a bit like that — you set sail and you think you know where you’re going, and you end up at a completely new place.”

Comment On This Story
COMMENT POLICY: We welcome comments from individuals and businesses. All comments are moderated. Comments are subject to rejection if they are vulgar, combative, or in poor taste.
REAL NAMES ONLY: All posters must use their real individual or business name. This applies equally to Twitter account holders who use a nickname.

0 Comments

You can be the first one to leave a comment.

Leave a Comment


HIGHER EDUCATION LINKS
LOCAL COLLEGE HEADLINES
Thursday, Jan 21, 2021
The College of the Canyons School of Personal and Professional Learning was presented an Honorable Mention award by the Academic Senate for California Community Colleges’ 2021 Exemplary Program Award.
Friday, Jan 15, 2021
The College of the Canyons ‘Canyons Promise’ free tuition program for new students is now accepting applications for the 2021-22 year.
Tuesday, Jan 12, 2021
California Credit Union invites college-bound students in Los Angeles County to apply for its 2021 College Scholarship Program.
Tuesday, Jan 12, 2021
Registration has begun for the College of the Canyons Spring 2021 semester, which will run from Monday, Feb. 8 - Thursday, June 3.
Thursday, Jan 7, 2021
Jasmine Ruys has been named as Vice President of Student Services at College of the Canyons, effective Jan. 1, 2021.
Keep Up With Our Facebook

Latest Additions to SCVNews.com
1839 - Gov. Juan B. Alvarado gives most of SCV to Mexican Army Lt. Antonio del Valle. [story]
Diseno map
Join the Santa Clarita Valley Water Agency (SCV Water) on Thursday, Jan. 28, from 6:30 p.m. - 8:00 p.m., to learn about and provide input on its Water Shortage Contingency Plan (WSCP).
SCV Water Encouraging Public to Provide Input on Contingency Plan
The Los Angeles County Department of Public Health confirmed 262 new deaths, including an additional death at Henry Mayo Newhall Hospital, and 8,512 new cases of confirmed COVID-19 countywide, with 22,360 total cases in the Santa Clarita Valley.
Thursday COVID-19 Roundup: Additional Death at Henry Mayo; 22,360 Total SCV Cases
SACRAMENTO – California State Epidemiologist Dr. Erica Pan issued the following statement Thursday advising providers that they can immediately resume the administration of lot 41L20A of the Moderna COVID-19 vaccine, which was temporarily paused on Sunday due to possible allergic reactions.
State Says Moderna Vaccine Administration Can Resume Immediately
As winds began to die down in the Santa Clarita Valley, firefighters were able to increase containment on the Towsley Fire to 53% Thursday.
Firefighters Reach 53% Containment on Towsley Fire
Supervisor Kathryn Barger, whose 5th District includes the Santa Clarita Valley, is supporting the effort by the California Public Utilities Commission (CPUC) to address concerns of communities throughout Los Angeles County, which continue to experience ongoing Public Safety Power Shutoffs (PSPS) initiated by Southern California Edison (Edison).
Barger Supports Efforts in Limiting Power Shutoffs; Public Hearing Set
Single Mothers Outreach (SMO) is proud to announce “Survivor” as the theme for the 11th annual Empowering HeArts fundraising gala set to take place virtually on Saturday, Aug. 7.
Nominations Open for Annual Empowering HeArts Awards
The College of the Canyons School of Personal and Professional Learning was presented an Honorable Mention award by the Academic Senate for California Community Colleges’ 2021 Exemplary Program Award.
COC Recognized for Personal, Professional Learning Program
The William S. Hart Union High School is looking for two new members to serve on the Measure SA Citizens’ Oversight Committee. These members will serve two-year terms with a maximum of three consecutive terms.
Hart Seeking Members for Citizens’ Oversight Committee
Santa Clarita-based Princess Cruises announced Thursday the sale of Pacific Princess to an undisclosed buyer.
Princess Cruises Announces Sale of Pacific Princess to Undisclosed Buyer
After a dayslong wind event hit the Santa Clarita Valley, most area residents power had been restored by Thursday morning.
SoCal Edison Restores Power to Most SCV Residents
The Los Angeles County Coroner-Medical Examiner’s Office identified Carlos Salgado-Ruiz, 35, of Santa Clarita, as the pedestrian killed after being struck by a vehicle in Saugus Wednesday night.
Pedestrian Killed in Saugus Hit-and-Run Identified
SACRAMENTO — Assemblyman Tom Lackey, R-Palmdale, introduced a bill Thursday that will allow individuals to be convicted for hate crimes.
Lackey Introduces Hate Crime Bill
1914 - Signal newspaper owner-editor Scott Newhall born in San Francisco [story]
Scott Newhall
The Los Angeles County Department of Public Health on Wednesday confirmed 262 new deaths and 6,492 new cases of COVID-19 countywide, as the county's rollout of an extremely limited vaccine supply continues at Dodger Stadium and five supersites including Six Flags Magic Mountain.
Wednesday COVID-19 Roundup: SCV Cases Total 22,232; Vaccines in ‘Extremely Limited Supply’
In what some hailed as the most important speech at an inauguration in modern American history, President Joe Biden called for a new era of unity and healing as he pledged to bring an end to the pandemic that has dramatically altered the lives of every American while leading the restoration of a battered economy.
Biden Inauguration: ‘This Is Democracy’ – President Calls for Unity in Inaugural Address
Almost directly after taking the oath as President of the United States, Joe Biden on his first day in office is expected to reverse a number of his predecessor’s policies and federal agency standards.
Biden’s Busy First Day: Action on COVID-19, Climate, Racial Equality
California Senator Scott Wilk (R-Santa Clarita) was unanimously selected as Senate Republican Leader-elect, Senate Republican Leader Shannon Grove (R-Bakersfield) announced Wednesday.
Wilk Named California Senate Republican Leader-Elect
Concluding with his oath to faithfully uphold and defend the U.S. Constitution, Joseph R. Biden became the 46th president of the United States at noon Wednesday.
New President Inaugurated: White House Changes Hands at Critical Moment in History
The Los Angeles County Public Health Department opened the Six Flags Magic Mountain vaccination site Tuesday, one of the five larger vaccination sites opened this week in conjunction with the Fire Department and other agencies.
Magic Mountain Opens Vaccination Site, Aims to Administer More Than 2K Doses a Day
California fired back on the Trump administration’s eleventh-hour attempt to gut the Endangered Species Act before the president left office Wednesday.
California Leads Charge Against Parting Gut of Endangered Species Act
After nearly a year of lockdowns, social distancing, widespread infection, and COVID-19-related death in Los Angeles, residents are preparing for the next chapter of the pandemic: vaccination distribution.
L.A. County Health Officials Address Challenges to Vaccination Distribution
California’s holiday COVID-19 wave appears to have crested, with state officials announcing Tuesday that hospitalizations and new infections are starting to decrease for the first time in weeks.
Officials: California’s Holiday COVID-19 Wave Appears to Have Crested
As coronavirus cases spiked to record highs and spurred statewide lockdowns this past summer, Governor Gavin Newsom and the California Legislature have scrambled to devise a COVID-19 aid plan for the state’s nearly $10 billion share of federal CARES Act funding.
California Leaders Blasted for Giving Less COVID-19 Aid to Small Communities
%d bloggers like this: