HowTo observe a NEA ?
To observe this flyby, you need to calculate by yourself, the ephemeris.
An ephemeris ? What is it ?
It is a table or a data file which give you the position of a celestial event in function of the time. Thanks to it, you can know where is the asteroid when you want to observe.
For doing that :
- Compute the ephemeris from your location with : https://ssd.jpl.nasa.gov/horizons.cgi. You can watch this tutorial video: https://youtu.be/K8lNw7UpueI if you need help.
- On the Unistellar application : In the “Explore” 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”.
- Start enhanced vision 10 min before and for 20 min.
- At the end take dark frames with the Science menu. Set the parameters as 25db – 3971ms time exposure – duration 02m00s.
- Send us a LOG with your evscope ID, city, your ephemeris table, time of the ephemeris / radec selected, and the time you did the dark frame at citizenscience@unistellaroptics.com.
HowTo observe an occultation ?
Check this complete how to guide 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.13 in the User Manual link)
✔️ Clear the memory of your eVscope
WARNING : this step can take up to 30 minutes – 2 hours depending on your Internet connection.
(p.7 in the User Manual link)
✔️ Charge the battery of your eVscope
✔️ Look for updates the Unistellar application (Apple and Android stores).
An hour before the occultation begins:
✔️ Level the tripod and install your eVscope
Turn it on, connect it to your phone and you are ready to start !
(see p.16 in the User Manual link)
✔️ Check the accuracy of the time on your phone
Use the Time.is website : https://time.is/
(see p.9 in the User Manual link)
Capture a screenshot of your phone
✔️ Connect your phone to the eVscope and launch the application
The application will synchronize its time on your phone, so it is important you start the application AFTER having used time.is as indicates here.
✔️ 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)
✔️ Focus
By pointing one of the first stars recommended by the app and using the Bahtinov Mask.
(see p.23 in the User Manual link)
✔️ Optional step : collimation
If your stars look like “potatoes” and have elongated shape, you need to collimate your mirror.
Check then this article from our FAQ : https://unistellaroptics.zendesk.com/hc/en-us/articles/360002267334-Collimation
(see p.21 in the User Manual link)
In the “Target” field enter the RA/DEC parameters and press GOTO 15 min 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.
Note: Once the recording has started, you can now switch back to the eVscope tab in order to try to see the occultation in real time. Please note that this is a really difficult event to catch on camera.
Do not activate Enhanced Vision during recording: it will damage your data.