Researcher at CNRS-IN2P3 Laboratoire d'Annecy de Physique des Particules Work on Vera C. Rubin Observatory and Dark Energy Science Collaboration (DESC) Also amateur astronomer when the sky is clearhttps://bsky.app/profile/alvindediaspar.bsky.socialhttps://bsky.app/profile/alvindediaspar.bsky.social/post/3mvfzne24uc2fCaptured this last Friday with my 250 mm f/4 Newtonian: a stack of 10x300s exposures through a Sloan g filter. The yellow arrow points to the 19th-magnitude historic Cepheid variable discovered by Edwin Hubble that proved M31 sits far outside the Milky Way. 🔭🧪13 Sep 2026 16:35 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mvfzne24uc2fhttps://bsky.app/profile/alvindediaspar.bsky.social/post/3muudzvrs3s2zYesterday I made a few images of the supernova Ia 2026aaiv which was discovered by ATLAS on September 1st in NGC 7331 (44 Mly from us). This animation blinks my image against a ZTF reference. 🔭 🧪06 Sep 2026 15:53 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3muudzvrs3s2zhttps://bsky.app/profile/alvindediaspar.bsky.social/post/3mtvxdhhels252 days ago I posted a picture of the eclipse showing a bright spot in the direction of the Moon. As some people suggested that it could be a satellite I wrote a python script to display the satellite trajectories at the time of the picture. Here is the result... 🔭🧪25 Aug 2026 13:46 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mtvxdhhels25https://bsky.app/profile/alvindediaspar.bsky.social/post/3mtsvbprnpc2gIn one of my picture of the eclipse, taken a little bit before sunset I have a spot on the Moon. It is probably an artefact but there is a slight chance that it is the flash of a meteorite smashing the moon. May I ask you to check your pictures for a similar spot around 18:50 UTC ? 🧪 🔭24 Aug 2026 08:31 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mtsvbprnpc2ghttps://bsky.app/profile/alvindediaspar.bsky.social/post/3mtmbjjwhp22cHere is a gif animation with my pictures of the total solar eclipse. Note that as I used a filter made from an Astrosolar sheet, the color is very close to the true solar color which is whitish. The Sun is not yellow. The reddish color at the end is the result of atmosphere absorption. 🔭🧪21 Aug 2026 17:21 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mtmbjjwhp22chttps://bsky.app/profile/alvindediaspar.bsky.social/post/3mszpopqyqc26A few images from the total solar eclipse in Spain 2 days ago. It was a stunning experience! One of those I will never forget 🧪 🔭14 Aug 2026 08:14 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mszpopqyqc26https://bsky.app/profile/alvindediaspar.bsky.social/post/3mriulj6lk22u This is WR 134, captured from my backyard with my Newton 250/1000 telescope. The final image combines 3.5 hours of Hα and 7.6 hours of OIII exposure. 🧪🔭25 Jul 2026 22:01 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mriulj6lk22uhttps://bsky.app/profile/alvindediaspar.bsky.social/post/3mq7e3dzuac2j😱😍 [contains quote post or other embedded content]09 Jul 2026 09:47 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mq7e3dzuac2jhttps://bsky.app/profile/alvindediaspar.bsky.social/post/3mpycghvaws26(480) Hansa is a ~56 km asteroid from the main belt. It is currently located at 1.85 UA from Earth in the direction of the Eagle constellation. Here is an animation of 12x180s exposures taken with my 250 mm telescope over 1 hour last Saturday. LEO satellites are such an annoyance ! 🧪🔭06 Jul 2026 14:29 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mpycghvaws26https://bsky.app/profile/alvindediaspar.bsky.social/post/3moganqe7uc23Our PhD student Laurent made this Interactive gravitational lensing applet. Try it... it is soooo cool 😀 https://lmagristella.github.io/random-science/interactive-gravitational-lensing-applet/16 Jun 2026 16:44 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3moganqe7uc23https://bsky.app/profile/alvindediaspar.bsky.social/post/3moah7avdgc27Allez, encore un petit coup de pouce pour financer ce projet très original de @galacticamille.com On y est presque ! [contains quote post or other embedded content]14 Jun 2026 09:25 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3moah7avdgc27https://bsky.app/profile/alvindediaspar.bsky.social/post/3miknpjfjis22This evening at sunset from the beach in La Serena (Chile) I took this photo of the Sun just before it disappeared. No need for fancy hardware, just a camera, a little bit of zoom and the atmosphere that acts as a filter and you get several sunspot groups. 🔭03 Apr 2026 02:17 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3miknpjfjis22https://bsky.app/profile/alvindediaspar.bsky.social/post/3mfrgk6q3fs2hAnd Fink is hosted at @ccin2p3.bsky.social [contains quote post or other embedded content]26 Feb 2026 14:42 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mfrgk6q3fs2hhttps://bsky.app/profile/alvindediaspar.bsky.social/post/3mfpfok4w2c2qThis is a major milestone for @vrubinobs.bsky.social The alerts on transient events are flowing. No doubt that this will trigger many important discoveries. [contains quote post or other embedded content]25 Feb 2026 19:21 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mfpfok4w2c2qhttps://bsky.app/profile/alvindediaspar.bsky.social/post/3mdivppzrjc2bI am blown away by Gemini's ability to decipher 17th-century civil records !!!28 Jan 2026 18:29 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mdivppzrjc2bhttps://bsky.app/profile/alvindediaspar.bsky.social/post/3mcsqyzxa222nFantastic show of northern lights tonight from my garden in the French Alps 🔭19 Jan 2026 23:06 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mcsqyzxa222nhttps://bsky.app/profile/alvindediaspar.bsky.social/post/3mbchrm5eik2mWhile playing with the LIDAR images in www.geoportail.gouv.fr from @ign.com I remembered that when I was a kid I used to walk in the forest up to the ruins of what we believed to be a motte-and-bailey castle. It is clearly visible here with its circular shape surrounded by ditches.31 Dec 2025 18:13 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mbchrm5eik2mhttps://bsky.app/profile/alvindediaspar.bsky.social/post/3maiskvg63c2sThis is a very sad news :-( [contains quote post or other embedded content]21 Dec 2025 13:17 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3maiskvg63c2shttps://bsky.app/profile/alvindediaspar.bsky.social/post/3mag2fjwrvk2fLook what I received 😀 The book looks very well written with clear step by step explanations and the pictures are gorgeous ! I was more a PixInsight guy but I think that I am going to start seriously using @siril.org. I like the spirit of this project !20 Dec 2025 10:59 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3mag2fjwrvk2fhttps://bsky.app/profile/alvindediaspar.bsky.social/post/3lyboxujogc2sIn France, the Moon was already totally eclipsed at moonrise making it difficult to spot in the twilight glow. 🔭07 Sep 2025 22:02 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3lyboxujogc2shttps://bsky.app/profile/alvindediaspar.bsky.social/post/3lxhgddtw5k2kA few times in a century, some individuals literally revolutionize a complete field of research thanks to a genius idea that they push and develop up to a point where it becomes a game changing experiment. So long Prof. Weiss ! [contains quote post or other embedded content]28 Aug 2025 11:19 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3lxhgddtw5k2khttps://bsky.app/profile/alvindediaspar.bsky.social/post/3lxfuzpleis2iA successful laser communication over 300 million kilometers with speeds up to 1.8 Mbps ! This is something that really impress me ! I would like to know the technical details that made possible this achievement. Is there a publication on this @esa.int ? https://www.esa.int/Enabling_Support/Operations/ESA_wraps_up_300-million-kilometre_optical_communication_campaign27 Aug 2025 20:36 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3lxfuzpleis2ihttps://bsky.app/profile/alvindediaspar.bsky.social/post/3lwegpv6qqc2kYet another wonderful image of Saturne and satellites from my friend Simon Labergère. This guy is so talented ! [contains quote post or other embedded content]14 Aug 2025 13:22 +0000at://did:plc:o5typjgnokfoo3ogrqc7gia4/app.bsky.feed.post/3lwegpv6qqc2k