Community Observatory

05/29/2026

It is difficult to believe right now with a thick cloud covering in Placerville but the predicted conditions for tonight look good. This is the readout from one of the weather apps that we use to decide if we can open. Darker colors are the best. Look at the “Seeing” line. It shows “Good” for 9 PM and “Average” for 10PM.

05/28/2026

What can you expect to see at the Community Observatory this Weekend?
The weather this week has been unsettled but Friday and Saturday nights are predicted to be mostly clear. We do have a full moon on Sunday and it will be quite full both Friday and Saturday.
This weekend is a “Blue Moon.” That doesn’t mean that it will be colored blue, it means that it is the second full moon in the same month. That happens because there are only 29.5 days between each full moon and most months are slightly longer. Each month’s full moon has a name. The “Full Flower Moon” fell on May 1st, and the second full moon that occurs on May 31st doesn’t have a name, so this moon gets the generic name of “Blue Moon.” Our “once in a blue moon” phrase reflects the fact that this doesn’t occur often. By the way, it is possible for one month to have a “Black Moon” where there is no full moon. Can you guess which month can have a black moon?
This is also a “Micro Moon.” That means that the Moon is near its “apogee” which is its furthest point from Earth in its orbit. Micro moons are up to 14% smaller than a normal full moon and up to 30% smaller than the biggest super moon. Luminosity is also correspondingly less during a micro moon.
Supernovae and novae are rare events. A common type of supernova occurs when a star destroys itself by imploding after it runs out of usable fuel. There have only been seven Supernovas that humanity since humans have been keeping records. We expect there to be only 1 to 3 supernovas in our galaxy per century. The last one that was visible to the naked eye was in 1064 AD.
But, when we look at the thousands of other relatively close galaxies, we can see distant supernovas much more frequently. There is a supernova visible right now in a galaxy 53 million light years away. You will likely get to see it when you visit us this weekend.
Novae are very different. They occur when a white dwarf star is in orbit with a red giant star. The white dwarf steals matter from the giant and it accumulates on the surface. The stolen gas on the white dwarf's surface builds intense pressure and heat until the hydrogen ignites in a thermonuclear explosion. Unlike a supernova, the white dwarf isn’t destroyed. It lives and the process begins again.
We are expecting to see a nova in the constellation “Corona Borealis.” This nova repeats on an 80 year cycle and it last flared in 1946. This constellation has rotated into view in the evenings now and It could flare at any time. It won’t be visually exciting since it will be a 10th magnitude star brightening to 2nd magnitude. That means that a star that is invisible to the naked eye will briefly shine about as bright as the stars in the Big Dipper.
Jupiter and Venus will be the only planets visible right now. Jupiter is very close to the horizon as the Sun sets. June will be the last month for you to see it in the evenings until November. Our summer months will be a planetary drought this year.
We are working with the Sacramento Valley Astronomical Society to host a solar viewing on Saturday from 9 AM until Noon. It will be at Elk Grove Horseshoe Park. Join us to view our very active Sun right now.
We plan to be open between 9 and 11 PM on Friday and Saturday this week. Be sure to check our website at communityobservatory.com after 3 PM on the day you want to come to be sure that we don’t have a weather closure. Come prepared to pay the college $2 to park. Bring a coat, it can be cold.

05/23/2026

Our observatory is supported by donations. We are going to be doing a series of fundraisers each third Tuesday of the month this Summer. These will be through Panda Express restaurants. When people order on-line on those days and enter the code "9015729" at checkout, Panda will donate 28% of the price to us. You get some excellent Chinese food and support the Observatory at the same time. Our first one is on June 16th.

Note - This is at ANY Panda Express, but the order must be on-line (Pickup or delivery is OK) and it must be for that specific date. You may order on-line and eat at the restaurant or take it home.

Apply code 9015719 in the Fundraiser Code box during online checkout at www.pandaexpress.com or via the App.

Here is the webpage with the information: Panda Express Community Programs

Please consider ordering from Panda Express on that date. Tell your friends and family.

https://www.community-fundraiser.com/virtual-fundraiser/events/promotions/4929d2d3-42eb-850c-c22b-c1a7499c9151/en/landing

Raise money for Community Observatory

05/22/2026

We are at Oak Ridge High School today showing the Sun to the students on their last day of school. Here is an image taken by a student of the Sun through our Hydrogen Alpha solar scope.

05/21/2026

What can you expect to see at the Community Observatory this weekend?

The forecast is for clear skies with good seeing. The 33 to 44% moon will not be too bright and will not interfere significantly with our seeing. On top of that, it may not even be very cold or windy. Why don’t you consider joining us this weekend?

We are in the transition between the Spring “Galaxy Season” and the Summer “Milky Way Season.” There are still some great galaxies to view from our inside scopes. Vega and Antares, two of the bright Summer stars will be peeking over the Eastern Horizon by the end of our viewing session.

Our excitement last weekend was seeing a new supernova in the distant galaxy NGC 5907. That is an edge-on galaxy that is also known as the “Knife’s Edge” or the “Splinter Galaxy.” It lies about 46.5 million light years away. The supernova was discovered on April 22nd by the ATLAS automated telescope. ATLAS stands for the “Asteroid Terrestrial-impact Last Alert System.” It is a system that continuously scans the sky looking for potential threats to Earth from asteroids or comets. Coincidentally, it also discovers things that have changed. In this case, a new “star” became visible in that galaxy.

To oversimplify, there are two types of Supernovae. Type I supernovae occur then a white dwarf star circling a red giant star steals enough material from its host to go critical. As the material accumulates on the surface of the white dwarf, it gets hotter and moves faster. When the atoms reach the speed of light, a fusion explosion occurs.

Type II supernovae occur when a giant or supergiant star runs out of usable fusible material. Stars are stable when the outward force of fusion and the inward pull of gravity are in balance. When fusion stops, the star collapses and an explosion occurs as the star implodes. Type II supernovae can leave behind a neutron star or a black hole. This supernova is a Type II. The two images today show the galaxy with the supernova. It was taken by Max with our 180 mm refractor in our imaging observatory.

Did you know that our imaging observatory is in regular use? We usually have a live feed from it during our public sessions. You will get to see an image of the scope and a live feed from the camera as it acquires its images.

Venus, the Moon, and Jupiter are all putting on a show in the west. Venus goes through phases just like the moon does. It is gibbous right now and it is the brightest thing in the evening after the Moon. Jupiter is the third brightest thing in the sky and it won’t be around for long as it will be too low to see by Independence Day.

Join us this weekend for a chance to see the supernova and for your last chance to see Jupiter until this winter. This summer, like the last few summers, will be pretty much without the spectacular planets. Saturn and Mars will be visible this Fall.

As always, get used to checking communityobservatory.com after 3 PM on the day you plan to visit. If we are going to have a weather cancellation, we will announce it by then.

05/20/2026

Black holes are a favorite topic at the Community Observatory.

05/18/2026

You may wish to view the western horizon shortly after sunset the next 3 days. The crescent moon will be near Venus and Jupiter. Here are the details:

Watch the crescent Moon dance with the planets when it returns next week.