Articles by Josef Chlachula

Impact point on Moon
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Falcon 9 Upper Stage lunar impact

July 24, 2026 Josef Chlachula Comments Off on Falcon 9 Upper Stage lunar impact
On August 5, 2026 at 1:35 a.m. CDT, the Moon will be approximately at the last quarter and more than 20 degrees above the eastern horizon in the North Central Region. At that time, the second stage of the Falcon 9 rocket will impact on its illuminated part on the left edge. In a telescope, impact of the 4000kg heavy […]
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Observing bright variable star Algol

July 21, 2026 Josef Chlachula Comments Off on Observing bright variable star Algol
Algol, designated Beta Persei (β Persei, abbreviated Beta Per, β Per), known colloquially as the Demon Star, is a bright multiple star in the constellation of Perseus and one of the first non-nova variable stars to be discovered. Algol is a three-star system, consisting of Beta Persei Aa1, Aa2, and Ab – in which the hot luminous primary β Persei […]
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RAC at RochesterFest 2026

June 28, 2026 Josef Chlachula Comments Off on RAC at RochesterFest 2026
Solar Observing at RochesterFest The Rochester Astronomy Club marked another successful community outreach event on Saturday, June 27, celebrating its second annual appearance at RochesterFest. To combat the summer heat, club members Randy and Lynn thoughtfully provided a sturdy yellow canopy shelter, offering a much-needed reprieve from the blazing sun. Once settled in the shade, visitors were treated to an […]
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Observing Alpha Centauri from Fort Myers Beach

February 8, 2026 Josef Chlachula Comments Off on Observing Alpha Centauri from Fort Myers Beach
On my recent trip to Fort Myers Beach, Florida, I set my astronomical observation goal to observe the nearest bright star, Alpha Centauri. Alpha Centauri is known to be 4.3 light years away. The really closest star is Proxima Centauri at 4.2 light years away, with a brightness of 10.43 – 11.11 magnitude. It is 2.18° southwest of Alpha Centauri […]
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Members Blog

The Story of the Universe in 100 stars

December 21, 2025 Josef Chlachula Comments Off on The Story of the Universe in 100 stars
In August I received a generous gift in the form of the book “The Story of the Universe in 100 stars”. I started reading and realized that each chapter – a star – contains an interesting story, something I did not know or forgot. And since the book is divided into 100 chapters, one chapter is the story of one […]
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Observe Titan shadow transits

July 9, 2025 Josef Chlachula Comments Off on Observe Titan shadow transits
This year 2025, we still have a unique opportunity to observe Titan’s shadow passing across Saturn’s disk as we learned at the last members’ meeting from Bob Fealey. Below is an adapted table taken from Sky and Telescope. For mid transits, there are links to Saturn in stellarium-web.org , opens in new tab. Upcoming Titan shadow transits (UT/CDT) Date DoW […]
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Sun at RochesterFest

June 26, 2025 Josef Chlachula Comments Off on Sun at RochesterFest
A public observation of the Sun at RochesterFest was planned for Tuesday 6/24 and for Saturday 6/28. Tuesday 6/24 we planned a public observation of the Sun at RochesterFest from 5 to 7 p.m. Actually, 2025 was the first year that RAC participated in RochesterFest. We were pleasantly surprised by the organizers, who provided transportation for our telescopes and other […]
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Hubble’s challenge to Josef after 35 years

January 20, 2025 Josef Chlachula Comments Off on Hubble’s challenge to Josef after 35 years
I’m old enough to remember the launch of the Hubble telescope. And right after that, the surprising image sharpness problems. NASA came out with a call this year for the 35th anniversary of the Hubble launch, basically for anyone interested in watching the sky overhead. All an observer has to do is tell others about the challenge and they’ll spot […]
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Comet C/2023 A3 (Tsuchinshan-ATLAS)

October 17, 2024 Josef Chlachula Comments Off on Comet C/2023 A3 (Tsuchinshan-ATLAS)
Comet C/2023 A3 (Tsuchinshan-ATLAS) has indeed become very observable with the naked eye after all. It can be photographed quite well with smartphones. Of course, a camera with a larger aperture provides a better image, not to mention the quality lenses. How to find the comet in the sky is described quite well in the Sky and Telescope article  Comet […]