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....

The solar cycle 25 started in 2020 and a maximum of activity is expected for 2025. In January 2021, specifically on the 16th, a new group...

I am very grateful to the AAVSO (The American Association of Variable Star Observers) for recognizing my contribution of over 500...

On December 21, 2021, the Great Conjunction of Jupiter and Saturn took place, expected by all the fans, but illusion truncated at least...

I have added in the "Projects" section, a new work DIY. The goal is to make Digital Setting Circles that will improve the visual...

Thanks to the helpful service of CalSky Alerter (https://www.calsky.com/) I received an email informing me that the ISS could be seen...

On June 19, 2020, the Moon occulted Venus for more than an hour. The trajectory of both along the ecliptic crossed. This phenomenon is...

You might think that when we look through the telescope to see or photograph the full moon we always see the same image, but the fact is...

The conjunction of Venus and Mercury took place this month of May 2020 at 9:44 local time, Venus passing through the north of Mercury at...

Every year Venus passes close to the Pleiades cluster (M45), but only every 8 years a perfect conjunction is produced, crossing the...

Venus is in an optimal position for observation when it is at its maximum elongation, i.e. when the angle between the Sun and Venus as...

Currently, the transits of Mercury take place in May (near its passage through the descending node) or in November (near its passage...

Iceland is an incredible destination to see nature. At the end of August, the conditions are excellent to enjoy the amazing landscapes of...

If you are interested in photometric or astrometric measurements with your equipment, you can get high precision in the timing of your...

Already Hipparchus of Nicea around 150 B.C. relied on the shadow of the Earth on the Moon during lunar eclipses to calculate the relative...

Today is August 4, 2019, and since July 25 the sun shows no sunspots or active regions on the visible surface towards the Earth. They are...

On July 16, 2019 there was a partial eclipse of the moon. The photo shows a moment of the eclipse, photographed from Majadahonda (Madrid)...

Building a stellar photometer clearly goes against the current trend. Almost all amateur photometrists use CCD cameras, and yet I have...

During the total eclipse of the moon on July 27, 2018, the Madrid Planetarium organized an observation in its esplanade with telescopes...

The images that the AllSky camera captures are a great help to know the current state of the sky. Being the camera in color we can...

During the months of November and December 2017, I dedicated the newly built Mini Observatory to the search for variable stars, finding 6...

On the occasion of a work trip to Helsinki, Finland, I decided to take the Canon 60Da camera and the tripod to the suitcase. I did not...

I have completed the design and assembly of a mini terrace observatory. With this system I have a second operational telescope using an...

The eclipse of August 21, 2017 was more than an astronomical event. In South Carolina there was no store without a sign referring to the...

From Cádiz I have been able to observe and make some photographs of the partial lunar eclipse on August 7, 2017. From this latitude, the...

A complicated objective of photographing with 11" telescope aperture and in urban environment is the intergalactic bridge between the...

On 9/5/2016 the weather in Majadahonda gave prediction that it would not be possible to see the transit of Mercury. And so it was until...

The sunspot called AR 2529 came into view on April 7, 2016. The photograph shows his status on April 9. Sunspots are regions of very high...

Supernova recently discovered in IC2207 with magnitude 17.5. The photo has been made with 14 stacked shots of 300s with LX200 8" and...