Meeting Monday, April 15th: White Dwarf Stars: Timekeepers, Planetary Graveyards, and Probes of Extreme Physics

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RCA General Meeting: White Dwarf Stars: Timekeepers, Planetary Graveyards, and Probes of Extreme Physics

Monday, April 15, 2024
Locations: Oregon Museum of Science and Industry (OMSI)

General Meeting at OMSI
Doors and Zoom meeting open at 7 pm
Social Time: 7 to 7:30
Main Meeting starts at 7:30
Locations: OMSI Auditorium
New Parking Fee: See below.

Note: The speaker will be speaking to us remotely via Zoom.

New Members Meeting from 6:30 to 7:30
Topics: Resources for Observing and Astronomy
Speaker: Alexe Mastanduno
Locations: OMSI Planetarium

Beginning Astroimaging from 6:30 to 7:30
Hosts: Jeff Eriksen and Robert Nelson
Location: Classroom 1 (adjacent to Auditorium)

Parking at OMSI
OMSI has recently partnered with Parking Kitty, the city of Portland's official mobile parking app. Our parking lots are now Parking Kitty pay lots. Parking rates are $5 + fees for 2 hours, $8 + fees for all-day parking, or $2 + fees for parking after 5 p.m. Members can pay for parking via the Parking Kitty app (parkingkitty.com), or mobile kiosks on the front plaza (credit card only). Strongly encourage you to download the app in advance. The North Lot code is ZONE 72000 and South Lot ZONE 72001.

White Dwarf Stars: Timekeepers, Planetary Graveyards, and Probes of Extreme Physics

White dwarf stars are the remnants left when lower-mass stars, such as our Sun, explode after depleting their fusable material. Although white dwarfs are less exotic than some of their more popular cousins, like neutron stars and black holes, recent studies have shown that they have amazing and unexpected properties. Along with their surprising properties, it can be a fun and challenging observing task to look for the white dwarfs in the hearts of planetary nebulae or in multiple star systems. This month's speaker, Dr Simon Blouin, is an expert in this type of star and is one of the authors of some of the recent studies. His description of his talk is below. It would be great to have you join us.

White dwarfs are the dense, Earth-sized remnants of stars, destined to cool down over billions of years after exhausting their nuclear fuel. This talk will delve into how these "dead stars" serve as valuable tools in astronomy. They act as cosmic clocks, allowing us to estimate the ages of stellar populations. Additionally, white dwarfs can reveal the chemical makeup of exoplanets they have consumed, and they provide a window into the behavior of matter under extreme pressure and density. New discoveries, including some very recent research I have been involved in, are challenging our understanding of white dwarfs. These findings suggest that some white dwarfs unexpectedly halt their cooling process for billions of years.

About Dr Simon Blouin

Dr. Simon Blouin is a Canadian Institute for Theoretical Astrophysics National Fellow at the University of Victoria, Canada. He was previously a Director's Postdoctoral Fellow at Los Alamos National Lab. He obtained his PhD in Physics from the Université de Montréal in 2019. His research focuses on white dwarf stars. In his free time, he enjoys hiking on beautiful Vancouver Island and playing with his 5-month-old son.

Meeting Monday, March 18th: Planet Formation Near and Far

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RCA General Meeting: Planet Formation Near and Far

Monday, March 18, 2024
Locations: Oregon Museum of Science and Industry (OMSI)

General Meeting at OMSI
Doors and Zoom meeting open at 7 pm
Social Time: 7 to 7:30
Main Meeting starts at 7:30
Locations: OMSI Auditorium
New Parking Fee: See below.

Note: The speaker will be appearing at OMSI in person.

New Members Meeting from 6:30 to 7:30
Topics: Preparing for Observing
Speaker: Alexe Mastanduno
Locations: OMSI Planetarium

Beginning Astroimaging from 6:30 to 7:30
Hosts: Jeff Eriksen and Robert Nelson
Location: Classroom 1 (adjacent to Auditorium)

Parking at OMSI
OMSI has recently partnered with Parking Kitty, the city of Portland's official mobile parking app. Our parking lots are now Parking Kitty pay lots. Parking rates are $5 + fees for 2 hours, $8 + fees for all-day parking, or $2 + fees for parking after 5 p.m. Members can pay for parking via the Parking Kitty app (parkingkitty.com), or mobile kiosks on the front plaza (credit card only). Strongly encourage you to download the app in advance. The North Lot code is ZONE 72000 and South Lot ZONE 72001.

Planet Formation Near and Far

One ongoing mystery is how solar systems form. The initial challenge was to explain the formation of our own Solar System. But, at this point, a sizable number of extra-Solar planetary systems are known and have been well-characterized observationally. Most of these systems are very different from our own (partly due to observation bias) and a new challenge is to explain the formation of this wider range of solar systems and what conditions distinguish the various types. This month's speaker is Professor Tom Quinn from the University of Washington and he will be able to enlighten us on this fascinating topic. Professor Quinn leads the N-Body Shop, which creates and analyzes simulations of the formation of structures in the Universe. His description of his talk is below. It would be great to have you join us.

Although there are significant outstanding puzzles, our understanding of the formation of the planets in our Solar System is well developed. In particular, a scenario where much of the material formed into small solid bodies, which then grow by mutual collisions, offers a foundation for understanding the formation of the terrestrial planets, the outer planets, and the populations of comets and asteroids seen in the present day Solar System. However, planetary systems come in a variety of architectures, with a large fraction falling into a class known as Systems with Tightly-spaced Inner Planets. In these systems, all the observed planets are closer to their parent star than Mercury is to the Sun. Such configurations lend themselves to discovering details of the planets such as their mass, radii, and composition. The question therefore arises: can the same scenario that we use for the formation of the Solar System also account for these very different planetary system architectures?

About Professor Tom Quinn

Tom Quinn is a Professor of Astronomy at the University of Washington and is currently the Chair of the Astronomy Department. He is also a member of the UW Astrobiology program. Professor Quinn's research interests focus on understanding the evolution of gravitationally interacting systems through computer simulations. These systems span a wide range of scales from small bodies in the Solar System to clusters of galaxies.

Vernal Equinox - March 19, 2024

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Credit: NASA

Jim Todd
RCA President
OMSI Director of Space Science Education

Spring finally arrives! Tuesday, March 19 is the vernal equinox for the Pacific Time Zone at 8:06 p.m., the day on which both the north and south poles of the earth are nearly equal distances towards the sun (92.6 million miles). At that instant, the sun stands directly over the Earth’s equator. The first day of spring is called 'the vernal equinox', vernal meaning 'green', and equinox meaning 'equal night', which simply means that on the equinox the hours of daylight are nearly equal to the hours of the night.

For much of the last century, the spring equinox has occurred on March 20 or 21. For 2024 (and in 2020), thanks to leap year, the equinox happens on the 19th in all U.S. time zones, making it the earliest spring we will have seen. Before then, the last time spring arrived this early was in 1896, 128 years ago.

As seen from Portland on March 20 and 21, the noon sun will reach its mid-point in the sky near 45 degrees from the southern horizon. On the day of an equinox, it is a good day for finding due east and due west from your own backyard. Just go outside around sunset or sunrise and notice the location of the sun on the horizon with respect to familiar landmarks.

In reality, March 16th is when day and night are both closest to 12 hours from Portland, Oregon, with sunrise at 7:18 a.m. and sunset at 7:19 p.m.. At the 45th latitude North, the time it takes for the sun to fully rise and set, which is several minutes, is added to the day and subtracted from the night, and therefore the equinox day lasts a little longer than 12 hours. Another reason why the day is longer than 12 hours on an equinox is that the Earth's atmosphere refracts sunlight. After March 17th, the daylights will be longer than nighttime until September 25th, after the autumnal equinox.

Happy Spring!

The World's Largest International Dark Sky Sanctuary has been Certified in Southern Oregon

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Dawn Nilson
Dark Sky Preservation Director

Congratulations RCA!

On March 11 a 2.5-million-acre area of eastern Lake County in a region often known as Oregon's Outback became the world's largest certified International Dark Sky Sanctuary. This Sanctuary is located within the largest, contiguous, pristine dark sky zone in the lower 48 states. Within the Sanctuary one will find Bortle 1 skies in a high desert environment with few trees. Dark sky protection of this area of Oregon is a major conservation advancement for astronomy, wildlife, and the starry heritage of the Outback's rural communities. Certification also provides an economic boost through dark sky tourism.

Rose City Astronomers has been involved with the nomination from the very beginning in 2019 when Dawn Nilson, our Dark Sky Preservation Director, developed the idea of a landscape-scale sanctuary in the Oregon Outback with the moniker "Oregon Outback." The idea was presented to RCA's Board in the form of a 10-page white paper prior to engaging others in the project. Dawn then became the strategist, manager, and author of the nomination submitted by the Oregon Outback Dark Sky Network. The project was significantly advanced forward with active sponsorship and engagement from Travel Southern Oregon, Travel Oregon, and Eastern Oregon Visitors Association. The project is a testament to the benefits of collaboration. It involved multiple federal, Tribal, state, and local agencies, non-profit environmental organizations, destination management organizations, businesses, and private advocates. Together, the collective of advocates are called the Oregon Outback Dark Sky Network. Go here to see DarkSky International's announcement of the certification.

More great news....on the evening of March 11 it was announced that Oregon's Governor Tina Kotek selected the Oregon Outback Dark Sky Network as the recipient for the 2024 Oregon Governor's Tourism Award. This Award represents the culmination of the tourism industry’s deep appreciation for long-time commitment, accomplishment and service by an individual or individuals who have enhanced the Oregon visitor experience and elevated the travel and tourism industry. As a member of the Network, RCA is included among the many who made the certification possible. Congratulations RCA! Thanks especially to those who provided night-time imagery of the Outback and who collected and assessed sky quality data in support of the nomination application.

Meeting Monday, February 19th: Science of the Europa Clipper Mission: T-8 Months to Launch!

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RCA General Meeting: Science of the Europa Clipper Mission: T-8 Months to Launch!

Monday, February 19, 2024
Locations: Oregon Museum of Science and Industry (OMSI)

General Meeting at OMSI
Doors and Zoom meeting open at 7 pm
Social Time: 7 to 7:30
Main Meeting starts at 7:30
Locations: OMSI Planetarium
New Parking Fee: See below.

Note: The speaker will be appearing at OMSI in person.

New Members Meeting from 6:30 to 7:30
Topics: Astronomical Terminology
Speaker: Alexe Mastanduno
Locations: OMSI Classroom 4

Beginning Astroimaging from 6:30 to 7:30
Hosts: Jeff Eriksen and Robert Nelson
Location: Classroom 1 (adjacent to Auditorium)

Parking at OMSI
OMSI has recently partnered with Parking Kitty, the city of Portland's official mobile parking app. Our parking lots are now Parking Kitty pay lots. Parking rates are $5 + fees for 2 hours, $8 + fees for all-day parking, or $2 + fees for parking after 5 p.m. Members can pay for parking via the Parking Kitty app (parkingkitty.com), or mobile kiosks on the front plaza (credit card only). Strongly encourage you to download the app in advance. The North Lot code is ZONE 72000 and South Lot ZONE 72001.

Science of the Europa Clipper Mission: T-8 Months to Launch!

This month we're hosting our second talk about upcoming missions in the Solar System. This month, Dr Carol Paty from the University of Oregon will be giving us her perspective. Dr Paty is a co-investigator on the ongoing Jupiter Icy Moons Explorer (JUICE) and upcoming Europa Clipper missions and a member of the science team for the Uranus Orbiter and Probe mission, which is currently in the planning stage. She'll again focus on the Clipper, since it is so close to launch, but might touch on some of the other missions, as well. Please see Dr Paty's description of her talk below. I hope you'll be able to join us.

Beginning with Galileo Galilei in 1610, the Jovian system of worlds has inspired us and provided a rich environment for paradigm change and discovery. Nearly 415 years from Galileo's discovery of the Jovian moons, we are poised to launch our next mission to further investigate the mysteries of Europa.

NASA's Europa Clipper spacecraft will launch in October 2024, with the goal of exploring Jupiter's moon Europa to understand its habitability. This robotic explorer will enter Jupiter orbit in April 2030, and, beginning March 2031, it will collect science data while flying past Europa 49 times. The mission will investigate Europa's habitability by studying its interior, composition, and geology, and will search for and characterize any current geologic activity including possible plumes. In this lecture, I'll discuss the mission's science objectives and how they will be addressed using an advanced suite of complementary remote sensing and in-situ instruments onboard Europa Clipper. From the short wavelengths of the ultraviolet to long wavelengths of radio, to a variety of compositional analysis techniques, to magnetic sounding of the interior, the diverse set of observations these instruments and investigations provide will paint a comprehensive picture of Europa's habitability and what lies beneath its frozen exterior. I'll also discuss the progress of the spacecraft assembly and testing as it makes its way to the launchpad.

About Dr Carol Paty

Dr. Paty is a planetary and space physicist specializing in studying magnetospheres of giant planets, moon-magnetosphere interactions, and icy moon interiors using a combination of simulations and spacecraft observations. She received her BA in Physics and Astronomy from Bryn Mawr College, and her PhD from the University of Washington in Earth and Space Science. She is a co-investigator on NASA's Europa Clipper mission and the JUICE mission and is actively developing new mission strategies to explore the Uranus system. Previously she worked on developing mission strategies to the Neptune-Triton system as part of the Trident Discovery mission team and the Neptune Odyssey Planetary Mission Concept Study. She currently sits on the steering committee of the Outer Planets Assessment Group and recently worked on the Planetary Science and Astrobiology Decadal Survey. Dr. Paty has been a Professor at the University of Oregon since 2018, prior to this position she spent 10 years at the Georgia Institute of Technology in the Department of Earth and Atmospheric Sciences developing a planetary science focus and helped found the Center for Space Technology and Research which bridged space research interests between the College of Science and College of Engineering. Her postdoc was spent working with the Cassini Plasma Spectrometer team at the Southwest Research Institute.

Lunar New Year, 2/10

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Jim Todd
RCA President
OMSI Director of Space Science Education

The Lunar New Year falls on February 10, 2024. It coincides with the date of the new moon and signals the start of the Year of the Dragon. According to Farmer's Almanac, the Dragon enjoys a very high reputation in Chinese culture and it represents auspiciousness and imperial power since ancient times.

In China, the start of the new year is celebrated with the Spring Festival, the biggest holiday. Traditionally, people give their house a big spring clean and hang couplets on their doors. Couplets are poetic lines about spring and prosperity written in gold or black on red paper. Setting off firecrackers is hugely popular, and children get hongbao, little red gifts with money inside, from older family members.

Groundhog Day 2024

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Jim Todd
RCA President
OMSI Director of Space Science Education

Groundhog Day 2024 on Friday, February 2 is a popular holiday with a long history and an astronomical event. It is near the halfway point between the winter solstice and the spring equinox, and its midpoint is a seasonal marker reminding us that spring will return once more. Groundhog Day derives from the Pennsylvania Dutch superstition that if a groundhog emerges from its burrow on this day and sees its shadow due to clear weather, it will retreat to its den, and winter will go on for six more weeks; if it does not see its shadow because of cloudiness, spring will arrive early. Many weather researchers questioned the groundhog's accuracy in predicting the weather, but some of the groundhog's fans may not agree!

In astronomical terms, Groundhog Day is one of eight major seasonal subdivisions of every year. They include the March and September equinoxes, the June and December solstices, and the intervening four cross-quarter days. The four cross-quarter days are Groundhog Day (February 2), May Day (May 1), Lammas (August 1), and Halloween (October 31).

The cross-quarter day (the midpoint between an equinox and a solstice) got its start with the Celts who called it Imbolc or lambs' milk as lambing season had just begun by February 2. The Celts also called the holiday Brigantia after the Celtic female deity of light, reminding them that the Sun was halfway on its journey to the spring equinox. Later, the Christian church called the holiday Candlemas, referring to the candles lit in churches that day to honor the presence of the Christ Child in the temple of Jerusalem. German immigrants to Pennsylvania brought their Candlemas legend with them in the 1880s. Since badgers weren't to be found they adopted the groundhog instead.

Old Groundhog stretched in his leafy bed.
He turned over slowly and then he said,
"I wonder if spring is on the way,
I'll go and check the weather today..."
~Author unknown, "Groundhog Day"