Majadahonda Astronomical Observatory

3I/ATLAS was discovered on July 1, 2025 . It was first detected by the ATLAS telescope in Río Hurtado, Chile, when it was approximately...

When primary cosmic rays collide with atoms in the Earth's atmosphere, unstable particles such as pions  and kaons  are produced. As...

The AAVSO has kinly sent me an acknowledgement for “ your invaluable contribution of over 2,500 variable star observations by...

FlashTime is a light flash generator synchronized with the PPS (Pulse Per second) of a GPS. It allows to generate light pulses to be...

I'm sure you've heard of AllSky cameras, but what is a HowSky camera? It is actually an invented concept: a camera with a wide field of...

ESA's Gaia mission has catalogued nearly 12 million variable stars, published in 2022 through Gaia Data Realease 3 (Gaia DR3). The...

I have added a new project to the website https://www.observatorio-majadahonda.com/motorised-flip-mirror which explains how to automate a...

Photometric observation of asteroids is one of the most interesting activities for amateurs. To analyse the rotation of an asteroid it is...

The supernova SN2023BEE, discovered on 1 February 2023, has been extensively photographed and measured, most notably by the Supernova...

b Persei (which is not the same as beta Persei, Algol) is an exciting triple star system with a hierarchical structure. The main part of...

How to help as an amateur to answer this question. Europa is, along with Io, Ganymede and Callisto, one of Jupiter's four largest...

In January 2021, a double (actually triple as we shall see) star was occulted by the asteriode Egeria. This post explains my experience...

The Minor Planet Center published in the bulletin "volume 49, number 2" corresponding to the period April to June 2022, a work of the...

The summer holidays are a good time to undertake new astronomy-related projects that are adapted to the circumstances of being on the...

Many thanks to the AAVSO for their recognition of the report of more than 1,000 photometric measurements with the PEP (Photoelectric...

Occultations of stars by the Moon are of interest in astronomy for measurements of lunar topography, measurements and even discovery of...

In this video you will see an eclipsing binary star system like you have never seen before ... I hope you enjoy it. It was prepared for a...

Asteroids are classified as potentially hazardous when they have a minimum distance of intersection of their orbit with the Earth of less...

During the pandemic confinement, I took the opportunity to undertake a major overhaul of the dome. The improvements I had to address...

I am fortunate to have a large terrace at home where I have been able to install two observatories: a rotating dome and a clamshell dome....