Jacobsen Observatory



The Theodor Jacobsen Observatory is the second-oldest structure on the campus. Built in 1895, the Observatory with its 126-year old, 6-inch refracting telescope is still offering celestial views of the wonders of the Universe. Here you will find information on opened nights, making reservations, a history of the telescope, a history of astronomy at the UW, and even an operating manual for the telescope. Come join us in a tour; there is no charge to learn about and view the night sky!

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TJO Evening Public Talks

The majority of the talks of the open house season are given by undergraduates at the University of Washington, individuals who are either majoring in physics and astronomy or are in other majors but really enthusiastic about astronomy. The level of the talks varies with the topic. Some are geared more to the younger visitors; most are geared for high school level. Please come and lend your support. By being in the audience you will be taking part in the educational program at the UW.

The talks on a given evening start approximately 5 minutes after opening and take place in the classroom that adjoins the Observatory. If the sky is clear enough, the dome will be open for viewing celestial objects through the ancient telescope. Reservations are strongly recommended for the talks, and visitors with reservations have priority viewing in the dome after the talks finish; no reservations are needed to tour the Observatory and take part in the exhibits, activities, and viewing through telescopes available on the Observatory grounds.

2018 Observing Season and Open Houses at Jacobsen Observatory
Month 1st Weds 3rd Weds Hours
April 4 18 8 – 10 pm
May 2 16 9 – 11 pm
June 6 20 9 – 11 pm
July 4 – Closed 18 9 – 11 pm
August 1 15 9 – 11 pm
September 5 19 8 – 10 pm

Talks Schedule

The topics and abstracts for the 2018 observing season are listed below. Thank you for all of your interest this past season, and we look forward to another successful series of undergraduate talks and observing of celestial objects.  These talks generally last between 20 and 30 minutes, giving us plenty of time to view celestial objects if the night skies are at all clear.


April 4- Aislynn Wallach – Future of Ground-Based Telescopes

April 18-Kiefer Dundas – Why Go to Mars?

May 2- 9:00 pm: Pubo Huang “The Formation of Binary and Multiple Star Systems.”
Stars, planets, and moons that are part of what is called a “three-body system” have weird properties. Pubo, who will be majoring in mathematics or astronomy (or both), will use examples of the Sun-Earth-Moon system and summarize the formation of binary and multiple-star systems. If clear, we should be able to view the multiple star systems Mizar (4 stars) and Castor (6 stars) that look like just one star to the naked eye. “Reservations are all taken; no more availability for the classroom or the dome visit.”

May 2- 9:30 pm: Keyan Gootkin “The Strange Study of Massive Stars.”
Keyan is majoring in astronomy and physics, and will start with giving us examples of massive stars: Rigel, Betelgeuse, Deneb, and others. At what mass is a star considered massive? How do these stars differ from our medium-mass star, the Sun? These stars will end their lives as supernovae. These explosions gave us the elements that we are made of. If clear, we can take a look at the stars Alkaid (Ursa Major, ~5 times Sun’s mass) or Polaris (Ursa Minor, ~6 times Sun’s mass). “Reservations are all taken; no more availability for the classroom or the dome visit.”

May 16- 9:00 pm: Tom Hemphill “Life in the Solar System Beyond Earth: Past? Present? Future?
Tom is majoring in astronomy and physics. The UW Astronomy Department is a leader in a relatively new field called astrobiology. Tom’s talk will introduce us to part of what an astrobiologist is interest in: The possibility of microbial life in  the solar system. Where would we look for the best possibilities of finding it? How will we look? What planets or moons have evidence for favorable conditions for microbial life? Towards the very end of the evening, we might get a look at Jupiter’s moon, Europa, a prime candidate for harboring microbial life.

May 16- 9:30 pm: Sam Reissmann “The Lives and Deaths of Stars.
Sam is majoring in aeronautics and astronautics; fortunately, one of our introductory astronomy courses got him interested in stars. Sam plans on covering the life cycles of both low-mass and high-mass stars, starting with star forming regions and the beginning of fusion. He will explain the process of fusion and how a star’s initial mass relates to how much “fuel” it has and how long it will live.  Stars like our Sun will expel the outer parts of their atmospheres as they die.  However, high-mass stars fuse more massive elements that results in spectacular deaths.

June 6- 9:00 pm: Arthur Vartanyan “High-Energy Blasts!
Arthur is a senior majoring in mathematics and is an alumnus of last year’s outreach class. He will be covering the absolutely most powerful blasts in the Universe, those connected with quasars, black holes, gamma ray bursters, hypernovae, and supernovae.  For those wanting something closer to home: Jupiter continues to make its appearance in the night sky.

June 20- 9:00 pm: Ally Witeck “The Lives and Deaths of Stars
Ally is majoring in physics and astronomy and just completed our outreach in astronomy course. Ally gave a planetarium presentation  about the lives and deaths of stars and will be bringing her knowledge to the Jacobsen Observatory, where we will be able to view real stars!  A few of the stars visible on this evening:

  • “Young Star”: Sadr (constellation of Cygnus) – mass is 14-16 times that of the Sun, relatively young for a star (few million years old), still has dust and gas clouds nearby from star formation, lifetime for stars having its mass is estimated to be less than15 million years.
  • “Old Stars”: Arcturus (constellation of Boötes) – estimated at over 7 billion years old. Stars of the globular cluster Messier 13 (constellation of Hercules) – estimated at around 12 billion years old. The Ring Nebula (constellation of Lyra) – a planetary nebula, the sun-like star that died had to be at least 10 billion years old.

The first-quarter Moon and Jupiter will also be visible in the southern sky.

July 4- Closed

July 18- 9:00 pm: Sylvia Kowalski “Topic TBD”
We have a UW alumnus returning to give the talk this evening: Sylvia Kowalski. Silvia is a dynamic and engaging speaker who has a lot of experience working with young people who are interested in astronomy.  You and your group will really enjoy the visit! The Moon, Jupiter, and Saturn will be visible in the night sky.

August 1- 9:00 pm: TBA Jupiter and Saturn will be visible in the night sky.

August 15- 9:00 pm: Keyan Gootkin “NASA and Research for All”
Keyan is an astronomy and physics major who started his academic career taking part in our PreMAP program (http://depts.washington.edu/premap/). He will be spending the first part of his summer at NASA and will be summarizing his experience there and the research he has been directly involved in as a first-year UW student.

  • Jupiter, Saturn, and Mars will be visible in the night sky.

September 5-  8:00 pm: TBA Saturn and Mars will be visible in the night sky.

September 19- 8:00 pm: TBA Saturn, the Moon and Mars will be visible in the night sky.


We apologize for not being able to accommodate everyone who wants to visit the Observatory and take part in the talks given by UW undergraduates. The classroom holds only 45 people; the dome that houses the 1892 refracting telescope can have a maximum of 12 adults at a time; children – while always extremely important to us – aren’t counted in this limit, and usually get the first opportunity to view through the telescope. Visits to the dome and discussions with Seattle Astronomical Society members last about 10-15 minutes. “Tickets” (which are free) to visit the dome are distributed during the start of each open house.

Seattle Astronomical Society members operate the ancient refracting telescope in the dome and can find fascinating treasures of the night sky. Their members are an endless source of information and enthusiasm about astronomy.


Reservations are strongly recommended for the talks as the TJO classroom holds only 45 people. Those with reservations have priority viewing for the dome.  While all are welcome to visit without reservations, please note that only the activities and the smaller telescopes set up in the Observatory grounds will be available. Usually for the July through September open houses, those without reservations do not get to visit the dome until close to closing time.

We are currently taking reservations through email only: tjores@uw.edu  Be sure to include the date you would like to attend and how many people will be joining you.  Unfortunately, we cannot accommodate visits outside of the regular nights during our observing season, April through September. No reservations are possible for October through March.

Special Group & School Reservations

We are especially glad to welcome adult recreation groups, students with special needs, K-12 classes, and home-schooling groups (and more) to the Observatory.  We can work with the supervisors/leaders/teachers on topics that they would like presented. We also have a wide variety of activities that we could include in the evening’s program. We are currently taking reservations through email only: tjores@uw.edu

Be sure to include the date you would like to attend and how many people will be joining you. The maximum number of visitors in the group or class is 45. If there are any special arrangements needed, also include that in your email. The classroom and all of the first floor of the Observatory are accessible; the dome (built in 1895) is not.


We are located at the north end of the University of Washington campus, just east of the Burke Museum, at the intersection of NE 45th Street and Memorial Way (17th Avenue NE). If you are coming from:

  • Eastside: Take 520 W to Montlake Exit. Left at 2nd light (on to Pacific). Come to 15th Avenue NE and make a right. The Physics/Astronomy building is on the corner, but this is NOT where you want to go. Continue up 15th Avenue NE until NE 45th Street. Take a right and continue east. You will see the Burke Museum on your right. Take a right at the next intersection. You will be going south on Memorial Way. If the parking gates are open (Gate 2), you will need to stop and get a permit. Lots N1 and N5 are the closest to the Observatory.
  • North or South: I-5 to NE 45th Street exit (University of Washington). Take NE 45th Street East until you see the Burke Museum on your right. Take a right at the next intersection. You will be going south on Memorial Way. If the parking gates are open (Gate 2), you will need to stop and get a permit. Lots N1 and N5 are the closest to the Observatory.


The University of Washington has lots of information on parking on campus for school and other bus transportation. Please visit the UW Parking Services web site for complete instructions and contact/permit information. If you are coming by car or car pool and it is earlier than 9 pm, then you will need to check in with the gate keepers at the north entrance (Gate 2) to the U of W campus for a permit and directions.

Theodor Jacobsen Observatory Newsletter

The Theodor Jacobsen Observatory Newsletter comes out roughly once per year and contains articles written by undergraduates at the University of Washington.

Spring-Summer 2017

Table of Contents – Fall 2017 Newsletter

Winter-Spring 2016
Winter-Spring 2015
Winter-Spring 2014:
Summer-Fall 2013:

Support the Theodor Jacobsen Observatory

If you would like to make a gift that will go directly towards enriching our educational public outreach efforts at the Observatory, visit the direct link  https://www.washington.edu/giving/make-a-gift/?source_typ=3&source=FROBSV.  Thank you for your support!

Friends of the Campus Observatory Fund

The fund was originally created to support maintenance and upkeep of the campus observatory; however, all of the funds currently go towards supporting our educational outreach open houses, activities, and programs.