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Notices by Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)

  1. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Tuesday, 10-Dec-2024 17:03:51 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ

    Today I received the following request to review a grant application from #Swiss National #Science #Foundation :

    "In this context, we would like to ask if you would be willing to support us by reviewing a recently submitted grant application. We know that this request places an additional burden on your busy schedule, but your expertise in this field would be instrumental in maintaining the highest possible standards of #research in #Switzerland. Thus we hope very much that you might agree to helping us with this task."

    So, they ask me to review a pretty long (they always are) grant application by the end of December... for free, to help and support them. So, according to them, I should change my plans for the next 3 weeks, which indeed are very busy, to work for free for Switzerland. My job is to do research, and not to support the grant application from another country.

    @academicchatter #academicchatter

    In conversation about 5 months ago from astrodon.social permalink
  2. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Monday, 02-Dec-2024 19:21:58 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    • Stay Grounded
    • Labos 1point5
    • CNRS Terre & Univers
    • Astronomers for Planet Earth
    • Labo Astro Marseille

    Five years of no flying
    โœˆ๏ธ โŒ โžก๏ธ ๐Ÿš… โœ…

    5 years ago, I realised that my #academic travels were emitting way too much #greenhouse #gas #GHG (up to 20 t #CO2 / yr) and hence that my #professional activity was not #sustainable. I thus decided to completely ban air #travel (#plane) and travel mainly by #train within #Europe.

    5 years later (i.e. now), my professional travels' #carbonfootprint dropped by **a factor 50**, without impacting my #publication records (compared to 2017 - 2019).

    I wrote a post for the #blog of @a4e about my experience. Check it out: https://astronomersforplanet.earth/five-years-of-no-flying/

    cc @labos1point5 @LAM_Marseille @CNRS_INSU @academicchatter @astrophysics @StayGrounded_net

    #Research #Science #sustainability #ecology #Earth #NoPlanetB #Climate #academicchatter #academicmastodon #ClimateChange #ClimateAction

    In conversation about 6 months ago from astrodon.social permalink

    Attachments


    1. https://media.astrodon.social/media_attachments/files/113/582/260/828/054/372/original/009c1a29ea1716ec.png

  3. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Wednesday, 23-Oct-2024 19:39:17 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    • Bon Pote
    • CNRS ๐ŸŒ
    • CNRS Terre & Univers

    Wow, the best-seller book "Understanding (almost) everything about the #climate " by @bonpoteofficiel Anne Brรจs and Claire Marc (@cnrs @CNRS_INSU) is now fully available online.

    This #book is easy to read and understand by everyone, even kids. It is written by climate experts.

    Definetely a must-read ๐Ÿ“–

    here: https://www.calameo.com/read/0064605871f75f8b9ee81

    Please share it in your community ๐Ÿ”„

    #ClimateChange #climate #Books #IPCC #outreach #science #openaccess #CNRS

    In conversation about 7 months ago from astrodon.social permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/113/355/763/963/782/055/original/c398e18a66889ff2.png

  4. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Wednesday, 06-Dec-2023 21:41:10 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    • XKCD Bot

    Wow, this @xkcd is really excellent.

    #Space tip: if youโ€™re ever lost in the inner #solar system, you can just type out the phrase โ€œOptimistic #Aliens measure space typographicallyโ€ in times new roman and use the dots as a #map

    ๐Ÿ˜…

    from: https://xkcd.com/2863/

    #Astronomy #Meme #Mastodon

    In conversation Wednesday, 06-Dec-2023 21:41:10 JST from astrodon.social permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/111/529/997/514/400/527/original/ef6b683df3491ec8.png
    2. Domain not in remote thumbnail source whitelist: imgs.xkcd.com
      Space Typography
  5. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Wednesday, 01-Nov-2023 17:11:32 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    • Stay Grounded
    • Labos 1point5

    #Today, I am celebrating my 4 years without flying โœˆ๏ธ.

    The #Earthโ€™s #climate is perturbed by #human activites. One of the easiest things to do towards #sustainability is to cut air travels. Thus, 4 years ago, I cut my frequent flyer cards and decided to #StayGrounded, using only low-#carbon travel means such as #train.

    #sobrietyversary #ClimateChange #climatecrisis #globalwarming #climateemergency #sustainabletransport @StayGrounded_net @labos1point5 @academicchatter

    In conversation Wednesday, 01-Nov-2023 17:11:32 JST from astrodon.social permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/111/333/876/518/571/322/original/9a38b09e08042438.jpeg
  6. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Monday, 23-Oct-2023 15:05:25 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ

    โ€œNext year, #SpaceX aims to average one launch every 2.5 daysโ€ source: https://arstechnica.com/space/2023/10/next-year-spacex-aims-to-average-one-launch-every-2-5-days/

    We have clear evidence now of the impact of #rocket ๐Ÿš€ launches on the #environment and the #atmosphere, together with the impact of #satellite ๐Ÿ›ฐ๏ธ entries. Still, #Musk wants to increase the frequency of #SpaceX launch next year !

    At some point, it will be a crime.

    credits: SpaceX

    #Space #sustainability #climate #ClimaChange #climatecrisis

    In conversation Monday, 23-Oct-2023 15:05:25 JST from astrodon.social permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/111/282/727/498/598/426/original/880263ea25781d18.jpeg

  7. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Tuesday, 17-Oct-2023 22:05:42 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    in reply to
    • Prof. Sam Lawler
    • Dr. Jรผrgen Knรถdlseder

    @jknodlseder @sundogplanets I thought it was few years for LEO, few decades for MEO and few centuries for GEO (likely the same source).

    Bottom line: exact time doesnโ€™t matter, itโ€™s way too long anyway.

    In conversation Tuesday, 17-Oct-2023 22:05:42 JST from astrodon.social permalink
  8. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Thursday, 07-Sep-2023 14:59:52 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    • European Commission

    The #night #sky in 2023.

    This shocking #photography was obtained from #Montana (#USA) over 17 minutes. It reveals the crazy number of #satellites orbiting the #Earth. Most of them are #StarLink (from #SpaceX / #Musk) and aim at providing internet to some remote places.

    StarLink is not the only project for space-based #internet: there are also #Kuiper (#Amazon), #oneWeb, #Iris2 (@EU_Commission), etc... which will send even more satellites into #space

    #Astronomy

    Credits: Matt C. Jackson

    In conversation Thursday, 07-Sep-2023 14:59:52 JST from astrodon.social permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/111/019/850/013/040/894/original/d9d63d92aaefafa9.png
  9. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Friday, 23-Dec-2022 08:11:27 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    in reply to
    • FediTips has moved!
    • Fedilab Apps
    • Sengi

    @feditips note that the software @sengi_app allows us to schedule toots which includes image description, unlike @apps (from what I could see). Also note that time on fedilab / mastodon is likely in UT and not in local time (Sengi is in local time).

    The Mastodon scheduler online tool doesnโ€™t allow us post images at all.

    In conversation Friday, 23-Dec-2022 08:11:27 JST from astrodon.social permalink
  10. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Thursday, 22-Dec-2022 01:14:14 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    • FediTips has moved!

    Hey @feditips, any way to efficiently schedule toots with picture attached ? Mastodon scheduling does not allow me to join a picture. Sengi is working fine, but limits to only 20 scheduled toots.

    Any other tips ?

    In conversation Thursday, 22-Dec-2022 01:14:14 JST from astrodon.social permalink
  11. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Sunday, 18-Dec-2022 23:45:54 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ

    Do you want to know how to make #stunning #astronomy #picture of the #night #sky without having a large #telescope ?

    So just follow this #thread about #StarTrail or #StarCircle and you shall be able to produce #photography like those attached.

    All the #images I will show in this thread are mine and available under Creative Commons Attribution 4.0 International License (CC-BY-4.0). Credits are available in the description.

    1๏ธโƒฃ / XX

    In conversation Sunday, 18-Dec-2022 23:45:54 JST from astrodon.social permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/534/850/763/597/939/original/3fbe68d6c6d35c17.jpeg

    2. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/534/850/784/095/103/original/187529f9909cc7d5.jpeg

    3. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/534/850/923/457/030/original/04a7106d934355fc.png

    4. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/534/871/847/030/547/original/5bbbd2bef518d012.jpeg
  12. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Sunday, 18-Dec-2022 23:45:52 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    in reply to

    2๏ธโƒฃ
    The method is quite straightforward: as the Earth rotates along the celestial poles, a long-exposure photography ? of the night sky ? will reveal that stars are trailing. ?

    in short, it would like like this โคต๏ธ

    In conversation Sunday, 18-Dec-2022 23:45:52 JST from astrodon.social permalink

    Attachments


  13. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Sunday, 18-Dec-2022 23:45:50 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    in reply to

    3๏ธโƒฃ
    As the Earth is spherical, if we point towards the celestial pole, star will slowly trail drawing a circle. If we point towards the celestial equator, star are quickly trailing along a line.

    If your field-of-view is large enough, you can even get both the celestial pole and equator.

    In conversation Sunday, 18-Dec-2022 23:45:50 JST from gnusocial.jp permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/534/945/291/974/956/original/5c7b9d5c7396bbb8.jpeg

    2. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/534/947/498/047/702/original/3b0c41d10eecc48e.jpeg
  14. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Sunday, 18-Dec-2022 23:45:48 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    in reply to

    4๏ธโƒฃ
    To make this kind of astrophoto, you don't need to have a telescope. You basically need to drop a camera on a tripod with its lens. Easy.

    However, after 30s of exposure, you would get only this. If you have a large field-of-view with your short focal lens, it does not trail much.

    In conversation Sunday, 18-Dec-2022 23:45:48 JST from astrodon.social permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/534/972/845/518/373/original/06db37874f582633.jpeg
  15. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Sunday, 18-Dec-2022 23:45:46 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    in reply to

    5๏ธโƒฃ
    if you want to make a star trail, you need to do a very long exposure. This is what you would get over :
    - 10 minutes
    - 30 minutes
    - 1 hour
    - 2 hour
    The more you can last, the better it is.

    In conversation Sunday, 18-Dec-2022 23:45:46 JST from gnusocial.jp permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/534/984/726/968/798/original/0b022d31337acda9.jpeg

    2. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/534/984/796/179/154/original/407f5164d1b55991.jpeg

    3. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/534/984/782/954/131/original/bfb4c0a52c71b9ff.jpeg

    4. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/534/984/768/989/857/original/9ab220d18c485023.jpeg
  16. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Sunday, 18-Dec-2022 23:45:45 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    in reply to

    6๏ธโƒฃ
    The result is available below, after more than 4 hours of exposure.

    My record is almost 13 hours of exposure. As an evidence for the long-exposure, you can see that the star Polaris has made half a circule, revealing half of the earth rotation.

    But, how can we reach such a long exposure time ?

    In conversation Sunday, 18-Dec-2022 23:45:45 JST from astrodon.social permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/534/998/921/401/322/original/a1c8653c5900f5b4.jpeg

    2. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/535/011/931/434/776/original/369a5448ba50dc49.jpeg

  17. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Sunday, 18-Dec-2022 23:45:43 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    in reply to

    7๏ธโƒฃ
    Long time ago, when we were shooting with film camera, it was so difficult. We were doing just one long-exposure. We had to balance between film sensitivity, focal ratio of the lens and star trail span.

    Here is a star trail I did in 2005 with a film camera over 2 hours at 200ISO and f/11. ?

    In conversation Sunday, 18-Dec-2022 23:45:43 JST from gnusocial.jp permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/535/037/098/331/713/original/e59beaf640b333e2.jpeg
  18. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Sunday, 18-Dec-2022 23:45:42 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    in reply to

    8๏ธโƒฃ
    Today, we are using digital camera which is so much better. However, we can't do just one long exposure as with film. Electronic noise does not allow us to do very long exposure. On top of that light pollution will contribute to fill out a bright sky.

    If one tries a long exposure of a few hours, he would get something like that, hence a completely saturated image.

    Instead of that, we do short (<1 minute) exposure and we then co-added them altogether.

    In conversation Sunday, 18-Dec-2022 23:45:42 JST from astrodon.social permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/535/049/668/162/465/original/75ba5930b3039a04.jpeg
  19. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Sunday, 18-Dec-2022 23:45:41 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    in reply to

    9๏ธโƒฃ
    So, what you actually need to do these pictures ?
    - a digital camera with a manual or BULB mode
    - a stable tripod
    - a lens, preferentially with a large field of view
    - intervalometer (or something that can control the exposure)

    This is what I use: a Canon 5D mk III with a Samyang 14mm f/2.8. The best tripod of the market (from swarovski optik) and a basic intervalometer.

    In conversation Sunday, 18-Dec-2022 23:45:41 JST from gnusocial.jp permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/535/073/744/463/920/original/6aede27f59c0321e.jpeg

    2. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/535/076/500/987/524/original/3cb6fe3253fb8f7c.jpeg

    3. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/535/078/236/295/966/original/79efe11e6ebb4fba.jpeg

    4. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/535/079/769/011/569/original/bbb5ca3c091a4546.jpeg
  20. Embed this notice
    Dr. Alexandre Santerne ๐ŸŒ (alexsanterne@astrodon.social)'s status on Sunday, 18-Dec-2022 23:45:39 JST Dr. Alexandre Santerne 🌍 Dr. Alexandre Santerne ๐ŸŒ
    in reply to

    ?
    My default setup is exposure of 60s every 61s. Star does not move quickly in the sky if you have a short focal length. However, if you leave gaps between 2 pictures, it will make wholes in the start trail, which are not great. This is a zoom of my previous star trail. Earth dash is the result of a 30s trail of a star, and the space between them is the result of 1s interruption to record the image and start the next exposure. Even 1s is enough to be clearly visible in the picture.

    In conversation Sunday, 18-Dec-2022 23:45:39 JST from astrodon.social permalink

    Attachments


    1. https://cdn.masto.host/astrodonsocial/media_attachments/files/109/535/093/123/822/888/original/44795c981a7162f9.png
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    Dr. Alexandre Santerne 🌍

    Dr. Alexandre Santerne ๐ŸŒ

    Astronomer, working @LAM_Marseille & teaching at Aix-Marseille #University (France) Expert in #exoplanet detection and characterisationInvolved in the #PLATO space mission from #ESA. #ESO telescopes user.Want to work in a #fair, #inclusive, and #sustainable #research #environment. Member of #labos1point5Toot a lot about #ClimateChange and #Climate. Boycott planes, travel by #train only.Interests: #photography #Astronomy #Space#fedi22

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