I spend this website many hours each week to share my knowledge and experience from the areas of Astronomy, Cars and Travels. Most pages are written in English that is not my own native language, so do not judge me too hard if you find grammatical errors and more.

Highlights!

(these pages could be a mix of Swedish and English)

Contents:

• NewsHigh lights on Astrofriend's homepage
• Astrophoto databaseLatest astrophotos March 29, 2025
• CometsGreat comets coming in the future March 30, 2024
• New linksInteresting information March 22, 2025
• Speech, Events and articles(English/Swedish) March 11, 2025

News:

Here I have collected news about my travels, astronomy, cars, history etc.

13:e april, 2025 Historia, Nya Slussen byggs upp

• Trappan från Slussen till Södermalmstorg börjar ta form.

  history/sverige-stockholm-slussen/ sverige-stockholm-slussen-start.html
  (Gamla slussen rivs och Nya Slussen byggs, Stockholm)
  

Senaste Slussen promenad längst ned på sidan.

Andra saker om Sveriges historia:

April 6, 2025 Travel Europe

• Our visit at Mallorca in Spain, 2025:

  travel/ europe/ spain-mallorca-2025/ 01-mallorca.html
  (Mallorca, Spain 2025)

Other travels in Europe:

March 29, 2025 Astronomy: Solar eclipse

• On March 29, 2025 we got a partial solar eclipse in Stockholm:

  astronomy/ astronomy-photo/ solar-system/ sun/ solar-eclipse-2025/ solar-eclipse-2025.html
  (Solar eclipse 2025, Stockholm)

Other astronomy photography:

25:e november, 2025 Historia, Älvsjö

• En promenad längs Långbrodalsvägen i Älvsjö med minnen från äldre tider:

  history/ alvsjo-langbrodalsvagen/ 01-langbrodalsvagen-sv.html
  (Långbrodalsvägen i Älvsjö)

  Uppdatering:
  Sträckan från Vantörsvägen till Älvsjövägen finns nu med, sid 4-7.

Andra reportage om gamla Älvsjö/Fruängen: Historia Älvsjö/Fruängen.

March 17, 2025 Astronomy: Project

• Now is time to take a new look at my EQ6 mount. Earlier I installed belt drive to it. Now I want to replace the internal driver with an open source driver, the OnStep driver:

  astronomy/ projects/ project-eq6-onstep/ 01-eq6-onstep.html
  (EQ6 mount and OnStep driver)

Update:
Setup up of auto guiding and test, page 9
Temperature, Humid and Pressure sensors, page 8
Installation of the board into the mount, page 7
Web browser parameter setup, page 5
Compile & Upload, page 4
Setup FYSETC E4 board, page 3

Other astronomy projects:

March 4, 2025 Music lists

• Update of my favorite music artists, music lists on YouTube:

  sound-image/ song-music-favorites/ favorite-music-list.html
  (Music lists)

Other Sound and Image:

March 2, 2025 Travel Europe

• We have stayed home for two years now, we are eager to do some traveling. When we visited Northern coast of Croatia 2022 we loved that place a lot. Now we plan for a similar trip in the Southern coast region of Croatia, from Dubrovnik to Split:

  travel/ europe/ croatia-south-2025/ 00-croatia-south.html
  (Zadar Croatia, 2022)

Other travels in Europe:

February 20, 2025 Cars, Chrysler Crossfire:

• Rust is one of the most boring things about old cars. Here I take a look at common places where it can be rust on a Crossfire:

  vehicles/ my-cars/ chrysler-crossfire/ rust-protection/ 01-rust-protection.html
  (Rust problem and protection)

Other Crossfire DIY:

February 19, 2025 Astronomy: Project

• Do you also have these black holes on your camera's sensor ? It could be dust but in this case it's dryer stains. After I had clean the sensor it's okay, but only one night outdoors and I get a couple of new stains, very frustrating. Here I do an attempt to avoid to get new stains:

  astronomy/ projects/ project-dew-sensor/ 01-dew-sensor.html
  (Dryer stains on the camera sensor)

Update:
Test three nights outdoors, page 3

Other astronomy projects:

February 17, 2025 Cars, Chrysler Crossfire:

• I got false alarm on my car. I take a look at it and do some measurements:

  vehicles/ my-cars/ chrysler-crossfire/ anti-theft-alarm/ anti-theft-alarm.html
  (False anti theft alarm)

  Update:
  Liftgate switch, page 9

Other Crossfire DIY:

29:e december, 2024 Historia, Götgatan

• Från Stockholms Stadshus kan man få en underbar utsikt över Stockholm, fri sikt i 360 grader. Här finns fotorafier från mina besök där år 1987 och 2004. Man kan se en del förändringar i bebyggelsen runt Stadshuset under de 17 åren:

  history/ stockholm-stadshuset/ 01-stadshuset-sv.html
  (Stockholms Stadshus utsikt under olika år)

  Andra platser med historia:

  history/ historia Sverige.html
  (Historia Sverige)

December 15, 2024 Sound, Music

• A streamer for music must be good to have. A bit expensive but can easily be built around a Raspberry:

  sound-image/ raspberry-musicstreamer/ raspberry-musicstreamer.html
  (Raspberry Music Streamer)

Other Sound and Image:

11:e december, 2024 Historia, Götgatan

• Tidigare gjorde jag ett bildspel med gamla fotografier från Hornsgatan. Nu har jag börjat göra motsvarande för Götgatan här i Stockholm. Det här blir inte en film utan en hemsida med fotografier på. Jag lägger till länkar med information för er som vill fördjupa sig i historien:

  history/ stockholm-gotgatan/ 01-gotgatan.html
  (Götgatan i nya och gamla bilder)

  Update:
  Många nya bilder inlagda, bland annat platserna för gamla biografer.

  Andra platser med historia:

  history/ historia Sverige.html
  (Historia Sverige)

6:e december, 2024 Fysik

• Efter några års uppehåll var äntligen Universitetets Julföreläsning tillbaka. Carl-Olof och Max Kesselberg framför sin fysikshow i Michael Faradays anda:

  astronomy/ astronomy-articles/ physics-show-2024/ physics-show-2024-sv.html
  (Julföreläsning i fysik med Carl-Olof och Max i Faradays mångåriga tradition)

Andra reportage om föreläsningar:Föredrag.

12:e november, 2024 Historia, Fruängen

• Under min uppväxt i Älvsjö under 1960-talet åkte vi ofta till Fruängen och dess moderna centrum. Dagens bilder med gamla minnen:

  history/ fruangen-centrum/ fruangen-centrum.html
  (Fruängens centrum)

Andra reportage om gamla Älvsjö/Fruängen: Historia Älvsjö/Fruängen.

November 28, 2024 Astronomy: Tutorial

• A year ago I started to use Siril for my pre processing astrophoto work. Works very well and I use it lot now:

  astronomy/ tutorials/ tutorial-siril/ 01-tutorial-siril.html
  (How to use Siril for pre processing astrophotos)

Update:
Added deconvolution, page 8

Other astronomy tutorials:

November 28, 2024 Astronomy: Tutorials

• A common problem when processing astrophotos is how to handle nebulas and stars. Totally different demands how to process. One way to solve that is to split up the image in two parts, one Star image and one DSO image. It can be done in Gimp with mask technique. I wrote about it before but now the tutorial is updated:

  astronomy/ tutorials/ tutorial-gimp-astrophotography/ 31-tutorial-gimp-astrophotography-separation-stars-dso-1.html
  (Gimp: Separation of stars and DSO)

Other astronomy tutorials:

November 24, 2024 Astronomy: Project

• Bracket frame 3D-printed. protection for cameras USB connector:

  astronomy/ projects/ project-small-practical-knobs-brackets/ 07-project-small-practical-knobs-brackets.html
  (Bracket frame for camera's USB connector)

Other astronomy projects:

16:e november, 2024 Astronomi, Historier

• Ikväll råder fullmåne, vi trotsar det och beger oss ut till Tyrestarervatet igen för att ta bilder av stjärnhimlen:

  astronomy/ astronomy-stories/ astrofriend-night-diaries/ astrofriend-night-diary-20241116-se.html
  (Tyrestareservatet i månsken nebulosor, november 2024)

Andra astronomihistorier:

November 13, 2024 Astronomy: Tutorials

• Auroras or Northern Lights is exiting to look at. I didn't understand that they can be so great where I live at latitude 59 degree. Now I'm planning to catch them with my DSLR camera and a wide angle lens. Here is my thoughts about what equipment to use:

  astronomy/ tutorials/ tutorial-aurora-equipment/ tutorial-aurora-equipment.html
  (Equipment for aurora photographing)

Other astronomy tutorials:

7:e november, 2024 Astronomi, Historier

• Med min astrokamrat Rolf åkte vi ut till Tyresta för att fotografera stjärnhimlen. Vi var lite tveksamma att åka iväg då vädret var lite osäkert. Men väntar vi några dagar så börjar Månen bli störande, efter lite funderande gav vi begav oss iväg. Extra spännande för mig är att testa utrustningen igen efter några justeringar:

  astronomy/ astronomy-stories/ astrofriend-night-diaries/ astrofriend-night-diary-20241107-se.html
  (Tyrestareservatet och nebulosor, november 2024)

Andra astronomihistorier:

November 6, 2024 Astronomy: Project

• With modern technology it's easy to get almost a perfect focus. But after a while it start to drift away because of temperature changes. Here is how I handle that problem:

  astronomy/ projects/ project-focus-temperature/ 01-focus-temperature.html
  (Focus and temperature drift)

Other astronomy projects:

October 30, 2024 Astronomy: Project

• To skip the hand controller for the SkyWatcher mount and direct connect to a computer is practical, but you need a special cable. Here is some information how to do that, even ideas about wireless control:

  astronomy/ projects/ project-eqdirect-cable/ 01-eqdirect-cable.html
  (EQDirect cables and wireless for SkyWatcher EQ6 and HEQ5 mounts)

Other astronomy projects:

October 27, 2024 Astronomy: Project

• I have moved what I have written about setting up a Raspberry with a GPS. Latest Raspberry Pi5 with KStars 64-bit, older system and GPS MNEA. They are now collected together here:

  astronomy/ projects/ project-kstars-gps/ 01-project-kstars-gps.html
  (KStars/Ekos/INDI and GPS)

Other astronomy projects:

October 27, 2024 Astronomy: Project

• I recently bought a Nikon D800 and an advanced Pentax FA 300 mm ED f/4 lens. My idea is to modify this camera for H-Alpha and replace my Canon 6D. Above that I need to build adapters, enclosures, voltage converters, guide camera, focus mechanism and drivers etc. You can follow the progress here:

  astronomy/ projects/ project-nikon-d800/ 01-nikon-d800.html
  (Project: Nikon D800 / Pentax 645 FA 300mm ED)

Other astronomy projects:

October 17, 2024 Astronomy: Project

• When using Raspberry computers you normally use Linux. For a Windows user it can be confusing. I have moved what I have written about Linux commands and udev rules to a common place, here:

  astronomy/ projects/ project-kstars-linux/ 01-project-kstars-linux.html
  (Linux commands and udev rules)

Other astronomy projects:

October 13, 2024 Astronomy: Project

• I need one more astroserver for my refractor telescope. Very pleased with the Raspberry Pi4 which I used to my earlier astroserver. But now there is a new Raspberry Pi5, more power full and almost the same price. If course I must have that one. It will be setup with 64-bit in mind:

  astronomy/ projects/ project-kstars-raspberrypi5/ 01-project-kstars-raspberrypi5.html
  (Project: Astroserver Raspberry Pi5)

Other astronomy projects:

5:e oktober, 2024 Historia, Vasastan

• En fin höstdag tar jag en promenad i Vasastan med en kamrat. Vi bestämmer oss för Vasaparken där det i dess närhet finns flera gamla byggnader med historia:

  history/ vasastan-vasaparken/ 01-vasastan-vasaparken-sv.html
  (Promenad i Vasaparken med historia)

  Andra platser med historia:

  history/ historia Sverige.html
  (Historia Sverige)

29:e augusti, 2024 Historia, Älvsjö

• Här finns mina reportage om Älvsjö historia, platsen där jag växte upp på 1960-talet:

  history/ history-of-alvsjo.html
  (Älvsjö historiereportage)

25:e augusti, 2024 Astronomi, Historier

• Nu har vi kommit mot slutet av augusti, då kan man säga att astronomisäsongen startar i Sverige. Normalt brukar jag börja med Perseiderna i mitten av augusti men i år blev jag lurad på det av massiva moln. Ikväll lovas det dock klart väder. Försökte locka med några kamrater ut på Björnö natirreservat, men det är söndag och många ska till arbetet i morgon. Ändrade mina planer och kör från balkongen ikväll istället. Här får ni följa förberedelserna där:

  astronomy/ astronomy-stories/ astrofriend-night-diaries/ astrofriend-night-diary-20240825-se.html
  (Säsongstart augusti 2024)

Andra astronomihistorier:

August 24, 2024 Astronomy: 3D-printing Project

• I have sometimes used my polar finder scope when aiming for the polar star. To make it easier I use a right angle prism. To fit that right angle prism to the polar telescope I 3D-printed an adapter I found on www, it worked but a bit wobbly, it could be better. Now I have designed my own adapter which is more stable:

  3d-printing/ 90degree-polarfinder-adapter/ 03-90degree-polarfinder-adapter.html
  (Project: 3D-printed right angle adapter EQ6/HEQ5 mount)

Update:
Now it can be downloaded as a STL file.

Other 3D-printing projects:

August 18, 2024 Car meetings

• Even if I'm most interested in cars it's always interesting to see other things that moves. This year we visited the event, Mälaren runt. Motorcycles driving around our lake Mälaren:

  vehicles/ malaren-around-2024/ malaren-around-2024.html
  (Lake Mälaren around, 2024)

Other car meetings in Sweden:

18:e augusti, 2024 Historia, Göta Landsväg i Stockholm

• Göta Landsväg, landsvägen till och från Stockholm har en tusenårig historia på vissa platser. Här är början på den, från Skanstull till Södertälje:

  history/ stockholm-gota-landsvag/ 01-skanstull-en.html
  (Göta Landsväg i Stockholm)

  Uppdateringar med fotografier på sträckan Årsta till Liseberg, sidorna 3 till 6.

Andra saker om Sveriges historia:

July 19, 2024 Travel Europe

• 13 years ago we did a four day trip to Brussels. Now when I try to remember which places there are on the photographs it's a bit hard to remember:

  travel/ europe/ belgium-brussels-2011/ 01-belgium-brussels.html
  (Brussels in Belgium, 2011)

Other travels in Europe:

July 4, 2024 Car meetings

• Today we visited a car meeting in Trosa and we went there with Ivan and his Chrysler 300:

  vehicles/ trosa-ivan-2024/ trosa-ivan-2024.html
  (Trosa car meeting, 2024)

Other car meetings in Sweden:

22:a juni, 2024 Historia, Skålgropstenar i Stockholm

• Skålgropsstenar finner man på många platser i Sverige. Här är några vi besökt i närområdet till oss i Stockholm.

  history/ skalgropsstenar-stockholm/ 01-skalgropsstenar-stockholm-sv.html
  (Skålgropsstenar i Stockholm)

Andra saker om Sveriges historia:

16:e juni, 2024 Historia, nattvandring i Älvsjö

• En fin mörk kväll år 2015 gick jag omkring i Älvsjö och fotograferade:

  history/alvsjo-nattvandring/ alvsjo-nattvandring-2015-sv.html
  (Nattvandring i Älvsjö, 2015)

Andra saker om Älvsjös historia:

9:e juni, 2024 Historia, Fornborgar

• Idag bestämmer vi oss för att ge oss ut i naturen. I Kagghamara söder om Stockholm skall finnas ett par mäktiga fornborgar, dit åker vi:

  history/ sverige-fornborgar/ kagghamra/ sverige-kagghamra-fornborg-1.html
  (Kagghamra Fornborgar i Södra Stockholm, 2024)

Andra saker om Sveriges historia:

May 21, 2024 Cars, Chrysler Crossfire:

• One of my H7 lamp got very hot and melted the socket. One more thing that I have to repair:

  vehicles/ my-cars/ chrysler-crossfire/ headlights/ 02-chrysler-crossfire-headlights.html
  (Melted H7 socket)

Other vehicles:

May 17, 2024 Astronomy: Lens data base

• When using a lens' built in focus motor it could behave different when controlling focus by remote. I have here collected some information from APT forum to get a better overview of which lenses is to prefer to use for astrophoto in that sense:

  astronomy/ tutorials/ database-apt-focus-af-mf-lenses/ database-apt-focus-af-mf-lenses.html
  (Data base: lenses autofocus behavior when remote controlled)

Other astronomy tutorials:

6:e maj, 2024 Bildspel

• Hornsgatan i äldre tider. Följ med på en promenad på Hornsgatan i gamla bilder, från 1880 till 1944. Från Södermalmstorg till Hornstull.

  photography/ slideshows/ photography-slideshows.html
  (Hornsgatan i äldre tider, 1880-1944, Stockholm)

Andra bildspel:

May 5, 2024 Cars, Chevrolet Corvette C3:

• My friend with a classic Corvette C3 1969 cab got problem with the rear axle. I suggested him buy a new used rear axle and prepare it for a replacement:

  vehicles/my-cars/ chevrolet-corvette/ chevrolet-corvette.html
  (Corvette C3 rear axle)

Other vehicles:

May 3, 2024 Photography: Macro

• Long time ago I built a macro setup. Never used it much but now I built version 2 of it, a better working one:

  photography/ macro-photography/ macro-slider-v2/ macro-slider-v2.html
  (Macro photography, slider setup v2)

Other Photography:

March 29, 2024 Astronomy: Astrophotos

• After all years my hard drives get full of astro photos, especially them who contain time lapse videos. What to do with them ? I collected all these time lapse videos in a nostalgic tour in Astro time lapse videos:

  astronomy/ astronomy-photo/ time-lapse/ time-lapse-slideshow.html
  (Star shows and Time Lapse videos)

Other astronomy photos:

• March 27, 2024 Photography: Slide shows

  Updated my page with slide shows, most from Stockholm:

  photography/ slideshows/ photography-slideshows.html
  (Slide shows, mostly from Stockholm)

Other Photography:

20:e mars, 2024 Resor till sjöss

Min fars äventyr som sjöman under åren 1937 till 1945:

• Vem har inte drömt om att göra en jorden runt resa någon gång i sitt liv. Min pappa Evert gjorde det redan innan han var 20 år fyllda. Han mönstrade på handelsfartyg och hamnade ända borta i Kina och andra länder i Asien. Det här skedde delvis under Andra Världskriget, det var många fartyg som gick under från minor och torpeder, även svenska fartyg. Tre av fartygen han var på förliste pga detta, dock något efter att han mönstrat av. Trevligt nog har jag en hel del bilder till pappas alla berättelser om de här 7 åren till sjöss. Denna spännande historia kan ni följa här:

  travel/ world/ evert-at-sea-1937-1945/ 01-evert-at-sea-start-sv.html
  (Min fars äventyr till havs åren 1937 - 1945)

Other history related:

February 11, 2024 Technique: Raspberry NAS

• Our NAS server aging. It has to be replaced by something new. I have read a lot of positive comments about setup a Raspberry as a NAS. It has low power consumption which is good with the increased energy prices we have today:

  technique/ raspberry-nas/ 01-raspberry-nas.html
  (Raspberry NAS)

Other about Techniques:

January 31, 2024 Astronomy: Astronomy Project

• Now when I almost finished the mechanical construction of my push pull screw focuser I must plan for the stepper motor controller. I need a hardware driver and control logic that can use INDI drivers:

  astronomy/ projects/ project-motor-focus-driver/ 01-project-motor-focus-driver.html
  (Project: Stepper motor driver)

Update:
Pin layout, page 6
Motor current, page11

Other astronomy projects:

January 25, 2024 Astronomy: Astrophoto

• It feels like that it's clouds on the sky every night. Is it really that bad ? I collected every astrophoto I had taken from 2013 until today and sorted they on months. From this I get a clear view which months is best. Note a long clear night I could had taken more than one object. Normal exposure length is 60 minutes per object:

  astronomy/ astronomy-photo/ database/ astronomy-photo-database-statististica.html
  (Astrophoto database statistics)

Note:
I live in a very light polluted area, Bortle Class 9. But anyway it's exciting to take astrophotos.

Other astrophotos:

January 15, 2024 Astronomy: Astronomy Project

• Info about how to drift align with PHD2 and guide calibration. Earlier it was a part of the EQ6 belt drive project:

  astronomy/ tutorials/ tutorial-drift-align-autoguide-calibration/ 01-tutorial-drift-align-autoguide-calibration.html
  (Tutorial: Drift align and auto guide calibration)

Other astronomy tutorials:

January 15, 2024 Astronomy: Astronomy Project

• I noticed that my old EQ6 project has a lot of visitors. And of course, it's about rebuilding it to belt drive. I have looked through the pages, updated it. Some of the pages has moved to separate project and tutorial pages. Some error in info and misspellings corrected too:

  astronomy/ projects/ project-eq6-dismantling-rebuilding/ 01-eq6-dismantling-rebuilding.html
  (Project: EQ6 Dismantling and rebuilding for belt drive)

Other astronomy projects:

11 januari, 2024 Nöjen i Stockholm

Restauranger:

• Här finns listat några restauranger som vi brukar besöka. God mat och hyfsade priser. Nytt är också en lista på restauranger som har pensionärs rabatter. Har inte hunnit besöka dessa själv än:

  pleasure/ restauranger/ resyauranger.html
  (Listor och kartor över restauranger i Stockholm)

Andra nöjen: Nöjen i Stockholm

11 januari, 2024 Nöjen i Stockholm

Takpubar:

• Kompletterad med några takpubar till. Sommarens projekt blir att besöka några av Stockholms takpubar. De har blivit väldigt populära på senare år. Här har jag listat de mer kända och gjort en karta så ni hittar dit:

  pleasure/ takpubar/ takpubar.html
  (Listor och kartor över takpubar och restauranger i Stockholm)

Andra nöjen: Nöjen i Stockholm

January 5, 2024 Home Theatre

• Now retired and I'm need of new toys. Some upgrades of the Home Theatre system. 4K player, PC, Xbox.

  sound-image/ home-theatre-resurrection/ home-theatre-resurrection.html
  (Home Theatre resurrection, 2019-2024)

Other Sound and Image:

December 25, 2023 Astronomy: Astronomy Project

• I have some thoughts about a monochrome camera. With that I must have some filters and a filter wheel. Here I'm playing around with the CAD and design that, maybe it can be done:

  astronomy/ projects/ project-filter-wheel/ 01-project-filter-wheel.html
  (Project: 3D-printed filter wheel)

Update:
Off-axis guide, page 8
Chassi, page 2, 3, 4
Wheel 3D-printed, page 1, 3, 4, 5

Other astronomy projects:

December 13, 2023 Astronomy: Project

• Long time ago I started a Flat Field Calibrator project where I use a LED stripe and 3D-printed parts. Got a lot of problem with the 3D-printer and the project fell in sleep. Now I started it up again:

  astronomy/ projects/ project-flat-calibrator/ 01-project-flat-calibrator.html
  (DIY/3D Flat field calibrator)

Update:
New adapter, for APO 130 mm refractor, page 4

Other astronomy projects:

December 6, 2023 Travel Europe

• Now it's October and in Sweden it's dark and cold. Time to travel South to Mediterranean. Spain is a nice country and we bought flight ticket to Alicante. The home flight goes from Barcelona:

  travel/ europe/ spain-alicante-barcelona-2023/ 00-alicante-barcelona.html
  (Alicante to Barcelona, Spain, 2023)

Other travels in Europe:

September 26, 2023 Astronomy: Project

• Since two years I have used a Linux based control system for my astro equipment. In the Windows world it's ASCOM drivers you use, in Linux it's INDI drivers. The INDI EQMOD driver control SkyWatcher's mounts. It's an old driver and I have to fix one or two problems with it. It's written in C++. It was 27 years ago I did something with C++, so it's a big step for me, but now I must solve it:

  astronomy/ projects/ project-indi-drivers/ 01-project-indi-drivers.html
  (INDI EQMOD driver)

Other astronomy projects:

September 17, 2023 Astronomy, observatory sites

• Michael's Torö observatory, Sweden:

  I got a new friend in the astronomy hobby, Michael. He has his own private observatory that I and a friend were invited to visit:

  astronomy/ observatory-sites/ toro-michael-observatory/ toro-michael-observatory.html
  (Michael's Torö observatory, 2023)

Other observatory sites:

August 18 20, 2023 Travel Europe

• Late in the summer I got a cruise as a birthday gift, it take us to Finland and the city Turku or Åbo as we say in Sweden. I haven't been there since the 1970s so it will be exiting. Finland belonged to Sweden during 700 years, we lost it 1809 in a war:

  travel/ europe/ finland-turku-2023/ finland-turku.html
  (Turku in Finland, 2023)

Other travels in Europe:

March 9, 2023 Astronomy: Project

• This time I take a look at the focus and the temperature, how long time does it take to stabilize ?

  astronomy/ projects/project-pentax645-300ed/ 01-pentax645-300ed.html
  (Pentax 645 300 mm f/4 ED lens)

Other astronomy projects:

January 29, 2023 Astronomy: Calculations

• Comet's speed differ from the sidereal rate. In most mounts a correction of the mounts speed can be input. Often these values are expressed in degrees/hour but need to be in arcsec/sec. I have done a calculator that do this conversion on my homepage:

  astronomy/ astronomy-calculations/ angle-conversions/ angle-conversions.html
  (Angle calculations)

Other astronomy calculations:

January 16, 2023 Astronomy: Tutorial

• One of my first tutorials I wrote was about how to do a relative guiding on comets. It guide on a star and the computer calculate the offset speed between the star and the comet and correct for that. I have looked through the text and updated links and added more photos. The software has developed a lot but still the principle is the same:

  astronomy/ tutorials/ tutorial-gimp-astrophotography/ 01-tutorial-gimp-astrophotography-introduction.html
  (Comet relative guiding)

Other astronomy tutorials:

December 7, 2022 Astronomy, solar eclipse history

• The Solar eclipse 1954 in Sweden:

  I have asked all my friends and relatives if someone have a memory from Sweden's last total solar eclipse 1954. I got an enormous response with lot of stories about this. I have collected them on a separate page and included some other information:

  astronomy/ astronomy-articles/ solar-eclipse-1954/ solar-eclipse-1954.html
  (Solar eclipse 1954 in Sweden)

Other astronomy articles:

December 6, 2022 Astronomy: Events reports

• I have collected my Astronomy events reports at one page:

  astronomy/ astronomy-articles/ astronomy-events-reports.html
  (Astronomy Events reports)

Other astronomy events reports:

September 11, 2022 HIFI

• At a car meeting I sat with my friends and got nostalgic. We talked about old HIFI and what we have had in earlier days. Here I have wrote it down:

  sound-image/ hifi-1970s-1980s/ 01-hifi.html
  (My HIFI in the 1970s to 1980s)

Other Sound and Image:

August 21, 2022 Boats / Monalisa

• Stefan has sent me even more photos of his renovation of his boat Ellinor, sister boat to my father's Monalisa:

  vehicles/ everts-cruiser-monalisa/ everts-cruiser-monalisa.html
  (Photos of the anchor)

Other ships and boats:

6 juli, 2022 Historia, Galgbackar

• Under ett par vandringar i Stockholms Stad med omgivningar har vi undersökt de platser där folk avrättats i gångna tider, Stockholms galgbackar.

  history/ galgbackar-stockholm/ 01-galgbackar-stockholm-sv.html
  (Avrättnings och galgbackar i Stockholm)

Andra saker om Sveriges historia:

June 2, 2022 Travel Sweden

• Steam trains are always exiting, I have done two travels with a steam train from Stockholm City to Nynäshamn. Both of them at Christmas. One more visit to the train museum at Nynäshamn:

  travel/ sweden/ nynashamn-steamtrain-2005-2009/ 01-nynashamn-steam-train.html
  (From Stockholm City to Nynäshamn by Steam train, Sweden from 2005 to 2009)

Other travels in Sweden:

28 mars, 2022

Mörka observationsplatser: Astronomi

• Örudden på Torö.

  I södra Stockholm på ön Torö är man långt från stadens ljus. Här är några foton från en parkering i naturreservatet:

  astronomy/ observationsplatser/ orudden/ observationsplats-orudden.html
  (Observationsplatser Örudden Torö, Stockholm)

Andra observationsplatser i Stockholm:

All other news: News.

October, 2022 Astronomy, Impact structures (meteorite craters)

• In Mars 2022 I passed close to the lake Västra Styran. I know I have read about it somewhere that it's maybe an old meteorite crater:

  astronomy/ meteorite-craters/ impacts.html
  (Meteorite crater Västra Styran, 2022)

It's number 10 on the map.

other meteorite craters:

January 5, 2022 Astronomy tutorial: Ekos Sequencer

• Included in the KStars is the Ekos. Ekos control the devices in your astroequipment. Included in this is a sequencer, a tool where you can hold your evening objects and the sequencer pick them up one by one in the most useful order. This is something new to me and all these advanced function is operated by the tiny Raspberry processor:

  astronomy/ tutorials/ tutorial-ekos-sequencer/01-tutorial-ekos-sequencer
  (Ekos Sequencer)

Other astronomy tutorials:

September 1, 2021 Bilskrotar kartor:

• För dig med gammal klassisk bil, när reservdelarna inte finns att köpa nya längre så blir man hänvisad till bilskrotarna. Jag har kompletterat mina tidigare listor med kartor för att lättare finna dom:

  vehicles/ bilskrotar/ bilskrotar-sverige.html
  (Bilskrotar Sverige)

Övrigt skrotbilar:

April 15, 2021 Astronomy: Project

• My friend Lars B do most of his projects from the very basic, cast worm gears, 3D-print details etc:

  astronomy/ projects/ project-do-it-from-basic-by-larsb/ 01-do-it-from-basic-by-larsb.html
  (Project: Lars B's projects)

Other astronomy projects:

Mars 23, 2021 Astronomy

prof Gösta Gahm

I, prof Gösta and Peter at the Sweden Solar system presentation, Gunilla is the photographer.

Something very sad has happen, in January 2021 I got the information that Gösta had passed away. We had known each other for more than 25 years, both I and Gunilla had him as a teacher in more than one of the courses we took in astronomy from 1995 to 2002 and we kept the contact since then. This meeting with the Jupiter model was the last time we saw him and at Christmas I got a greeting from him, since then nothing. Goodbye Gösta, we hope you have a great time up among the stars !

Gösta has one asteroid named after him: 10997 Gahm.

Lars and Gunilla

• astronomy/ astronomy-articles/ sweden-solar-system-jupiter-2019/ sweden-solar-system-jupiter.html
  (Sweden Solar system, Jupiter)
• https://en.wikipedia.org/ wiki/ Gösta_Gahm
  (Gösta Gahm, Wikipedia)

Other astronomy events reports:

29 januari, 2021 Resor till sjöss

Nyheter om det år 1940 förlista fartyget S/S Sylvia:

• En släkting till en av de omkomna har hittat till min sida om fartyget S/S Sylvia och har en del att berätta:

  vehicles/ ship-sylvia-1940/ 01-sylvia-sv.html
  (Fartyget S/S blir torpederat år 1940)

Other history related:

January 9, 2021 3D CAD

• In this project I make drawings for GT2 pulleys that I will use in my lens focuser:

  3d-printing/ camera-lens-focus-gears/ 01-camera-lens-focus-gears.html
  (Making drawings for GT2 pulleys to lens focuser)

Other 3D Printer and CAD projects:

29 juli, 2020

Modellbåten Flamingo från Wentzel: Hobby

• När jag var omkring 9 år köpte min pappa mig min första modellbåt i trä. Den har nu efter 25 år på irrfärder hamnat hemma hos mig igen:

  vehicles/ models/ 02-wentzels-flamingo.html
  (Modellbåten Flamingo från Wentzel, hobby)

Andra båtar i full skala:

November 8, 2019 Astronomy / seminar

• Seminars "The ALMA Fornax Cluster Survey" by Nikki Zabel.

  How does the galaxy cluster environment affect molecular gas and star formation? 2019
  (Institution of Astronomy, Stockholm's University)

Other speech, seminar and articles:

May 19, 2019 Sound / Image

• Biograf (Cinema) Sländan Museum:

  sound-image/ cinema-slandan-museum/ cinema-slandan-museum.html
  (Biograf Sländan Museum)
• We had a visit to a camera flee market today, we was a bit early and found this when we waiting, a cinema machine museum.

Other things about sound and cinema:

27 januari, 2019

Nya kartor över fornlämningar: Fornhistoria

• Kartor för fornfynd, det är för dig som gillar att vara ute i naturen och leta efter vår spännande historia.

  Här finner du de nya kartorna:

  history/ sverige-fornlamningar-kartor/ fornlamningar-kartor-sv.html
  (Fornlämningskartor, Sverige)

Other history related in Sweden:

All other news: News.

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