Welcome

What is it ?

It is an astronomical event defined by the passage of an object in front of a star.
The star is completely or partially obscured. Here we will be interested by asteroid occultation. For example, see the next GIF.

Why observe them ?

Asteroids were unknown until 1801, with the discovery of the largest asteroid one : 1 Ceres, which reaches 930km in diameter ! The current scientific consensus states that Main-Belt asteroids between Mars and Jupiter were supposed to turn into a planet during the creation of our solar system.

Due to the huge gravity of Jupiter, this Main-Belt remained as it is, a collection of objects and not a single body. Therefore, we can say that these asteroids are witnesses to the creation of our solar system and our planet. By studying them more closely, we can learn about their trajectory and identify their shape, their size, their composition etc. And possibly learn about the origin of life. Observing asteroid occultation is about observing an asteroid passing between a bright star and us.

HowTo guide

First, go to our occultation prediction page and select the occultation you want to do.

To find out if an occultation is passing through your home, simply zoom by scrolling on the map. If you live between the two orange lines, you are able to see the occultation.

For your information :

CEST/CET time* is the Central Europe Summer Time. It concerned France, Spain, Italy, Germany, Switzerland etc…

BST/GMT time* concerned only Portugal and United Kingdom

EEST/EET time* concerned only Finland

Check this complete User Manual Link on how to catch one with your Unistellar eVscope.

Before the occultation :

✔️ Check the weather 

We suggest you use the clearoutside app or website.

(see p.5 in theUser Manual link)

✔️ Clear the memory of your eVscope

WARNING : this step can take up to 30 minutes – 2 hours depending on your Internet connection.

(see p.9 in theUser Manual link)

✔️ Charge the battery of your eVscope

✔️ Look for updates the Unistellar application (Apple and Android stores).

30 min before the occultation begins:

✔️ Set up your eVscope and level the tripod 

Make sure you find have a good view on the constellation of the event

(see p.13 in theUser Manual link)

✔️Launch the Unistellar application

Make sure that your smartphone is connected to your 4G/Wi-Fi BEFORE launching the application. Then, launch first the app WITHOUT launching your eVscope. 

✔️Turn your eVscope on

You can connect your phone to your eVscope now. 

✔️ Launch Autonomous Field Detection

So that your eVscope knows precisely how to go to the occulted star.

(see p.17 in theUser Manual link)

✔️ Focus and collimation

By pointing one of the first stars recommended by the app and using the Bahtinov Mask.

(see p.18 in theUser Manual link)

15 minutes before the occultation:

In the “Target” field enter the RA/DEC parameters and press GOTO before the beginning of the occultation. In the “recording” tab enter the Gain, Exposure and Duration parameters, check again your values and click on “Launch” at the start time.

 

Remark : Once the recording has started, you can now switch back to the eVscope page to try and see the occultation in real time. Please note that this is a really difficult event to observe directly. 

Do not activate the enhanced Vision during recording : it would delete all the data.

 

🏡 Once at home :

✔️Transfer your data 

Once recording is over, please transfer your data. (If you need help please check: HowTo upload my data ? )

✔Tell Unistellar that you participated

To make sure your contribution is properly processed, please fill this very short survey by telling us your name, the serial number of your eVscope and if you agree your name can be mentioned in the EURASTER/IOTA report on their website (keep in mind that, to prove the accuracy of your observation, its GPS coordinates will be published too). 

 

By filling this survey :

For Europe observation:  https://docs.google.com/forms/d/e/1FAIpQLSdTkzChnn1bQyea3ftqAKB36oolE_UgyUcYd-n-_bdX_PSDNw/viewform?usp=sf_link

For North America observation:

https://docs.google.com/forms/d/e/1FAIpQLSeuv0Xel9jQtEMndaU5j3j46Ff2J42hxEohj5yRUjcfk0MpzQ/viewform?usp=sf_link

⚠️ Please, fill this survey, we can only process data registered that way ⚠️

🥂 Congratulations ! 🥂

You have achieved your citizen science mission. Unistellar and SETI Institute scientists thank you and hope you enjoyed it.

We will publish the occultation results soon on EURASTER.

It is a small step for you, and a big step for citizen science.

What is it ?

Planetary defense is the observation of hazardous asteroids. This type of asteroid is characterized by their orbit which crosses the orbit of the earth. Thus, these asteroids can potentially, collide with our planet.

Why observe them ?

Observing these asteroids allows us to refine the trajectories and determine their sizes and shapes, which are still little known. By doing so, we participate in the protection of our blue planet.

HowTo guide

Read the Planetary Defense Program of the current month to discover the targets. Two scenarios, the Near-Earth Asteroid is or is not in the Unistellar application’s database.

 

If the NEA is in the database : 

✔️ Connect your phone to the eVscope and launch the application 

✔️ Launch Autonomous Field Detection
So that your eVscope knows precisely how to go to the occulted star.
(see p.18 in the User Manual link)

✔️ Click on the “Explore menu”

Enter the name of the asteroid and click on GoTo.

✔️ Enhance vision “menu”

Once the GoTo is done, activate the Enhance vision and click at the top left in the parameters. Then observe the duration indicated in the current Planetary Defense Program and adjust it if it is necessary.

✔️ Dark frame

At the end of the observation, take a dark frame with the Science Menu. Set theses following parameters :

  • Gain: 25dB
  • Exposure time: 3971ms
  • Duration: 02m00s

A tutorial picture below.

✔️ Transfer your data

Please, upload your data.

✔️ Tell Unistellar that you participated
Then, send us a LOG at citizenscience@unistellaroptics.com with :

  • Your eVscopeID
  • The city where you observed
  • Asteroid’s name
  • Time you start/end the observation
  • Time you did the darkframe

If the NEA is NOT in the database : 

You will need to calculate by yourself, the ephemeris. What is an ephemeris? It is a table or a data file which give you the position of a celestial event in function of your location and the time.

✔️ Compute the ephemeris from your location with Horizons: 
Horizon Website: https://ssd.jpl.nasa.gov/horizons.cgi
Video Tutorial: https://youtu.be/K8lNw7UpueI

✔️ Connect your phone to the eVscope and launch the application

✔️ Launch Autonomous Field Detection
So that your eVscope knows precisely how to go to the occulted star.
(see p.18 in the User Manual link)

Then, in the “Science” menu, click on “Asteroid occultation” mode. At the bottom, you have the possibility to enter the coordinates of the asteroid. Here, enter what the ephemeris gave you and do not forget to click on “GoTo”

✔️ Enhance vision “menu”

n the “eVscope Menu”, start enhanced vision 10 min before the date of the ephemeris you have used and observe for 20 min.

✔️ Dark frame

At the end of the observation, take a dark frame with the Science Menu. Set theses following parameters :

  • Gain: 25dB
  • Exposure time: 3971ms
  • Duration: 02m00s

A tutorial picture below.

✔️ Transfer your data

Please, upload your data.

✔️ Tell Unistellar that you participated
Then, send us a LOG at citizenscience@unistellaroptics.com with :

  • Your eVscopeID
  • The city where you observed
  • Asteroid’s name
  • Ephemeris table
  • Time of the ephemeris / radec selected
  • Time you did the darkframe

"What a Feeling:" A Testimonial from an Occultation's Detector

Here is what Morand, one of Unistellar’s first citizen astronomers, wrote about his detection of asteroid 2000 UD52:

When I received this occultation “mission”, I was a little confused. It seemed quite simple, the event was known, so no chance discovery by amateurs … But hey, I played the game. I had just received the telescope.

Excited but a little late as always, I followed the procedure and … I saw nothing … However, I sent the data. And, a few days later, I learned that the occultation was clearly visible on the data, that I was the only Unistellar to have observed it, and that the scientific value was real : the occultation was very brief, 0.3s (the predicted maximum was 0.8s), therefore particularly difficult considering the small size of the asteroid (~ 6.6 km) and the width of its centrality band.

Having observers near and into the centrality band will allow to better determine the position of the asteroid, and therefore to refine its orbit ! What a feeling !