The asteroid Racheldavis, which will occult a 9.8 magnitude star this weekend, was named in honor to Rachel Michelle Davis who, when she was a high school student, reached the final of a renowned science competition (Intel Science Talent Search). One of her rewards was then to have an asteroid named Racheldavis.
She is now a renowned 3D printing scientist with whom we started to talk to. One of our goal is to allow her to have a visual representation of her asteroid. If many amongst us observe it, we could successfully model its shape and size and even determine a possible presence of a moon or even a double asteroid.
Observing an asteroid occulting a star is a difficult task. Keep in mind that, whether or not your eVscope detect the occultation, both positive and negative results will provide useful information for scientists.
The observing campaign will happen from the Friday May 22nd 2020 and Saturday 23 between 01:39am et 01:41:30am (UTC+2).Thanks to the power of your eVscope you may be able to observe it from anywhere, even from downtown. If you can look up toward the South/Southwest at approximately 35 degrees of altitude, you will be able to observe the star being occulted for up to 1.1sec.
If you are interested, please check the instructions below to observe this celestial event. Please make sure you read them before, it will ensure your observation runs smoothly.
Taking part in Citizen Science campaigns
Detailed documentation :
User’s Manual link :
Before the occultation :
✔️ Check the weather
You can check the clearoutside app or website
(see p.13 in the User’s Manual link)
✔️Empty the memory of the eVscope
WARNING : this step can take up to 30 minutes – 2h depending of your internet connection
(p.7 in the User’s Manual link)
✔️Recharge the battery of the eVscope
✔️Update the Unistellar application version
It has to be 1.0 or above
✔️Check the time on your phone
Time.is website : https://time.is/
(see p.9 in the User’s Manual link)
One hour (or more if you are a beginner) before the occultation, please follow these instructions.
✔️Install your eVscope
Turn it on, connect your phone and you’re ready to begin !
(see p.16 in the User’s Manual link)
✔️Autonomous Field Detection
So that your eVscope knows precisely how to go to the occulted star.
(see p.18 in the User’s Manual link)
By pointing at a very bright star and using the Bahtinov Mask.
(see p.23 in the User’s Manual link)
✔️Optional step : collimation
If your stars look like “potatoes” and have elongated shape, you need to collimate your primary mirror.
(see p.21 in the User’s Manual link)
30 minutes before the recording time :
✔️Prepare the recording
In the “Science” tab, click on “Asteroid occultation”.
In “Target”, put the star’s coordinates :
RA :14h 45m 29s
DEC :-00°37m 12s
IMPORTANT : here for DEC : click on “-” then on “0” and on “0” for the first coordinate.
⚠️ DON’T FORGET THE “-” BEFORE THE “0” ⚠️
Then, click on “GoTo”. You can come back on the “eVscope” tab during the “GoTo” if you want to see the star.
✔️2 minutes before the launch :
In the “recording” tab enter the next information
Gain : 30 dB
Exposure time : 100 ms
Time duration : 02m30s
Check again your values and click on “Launch” at
Remark : Once the recording launch, please stay on the “Asteroid occultation” page where an orange circle is rotating (indicates the recording is in progress).
✔️Transfer your data
Once the recording is over, please transfer your data. (If you need help : https://help.unistellar.com/hc/en-us/articles/360013803619-eVscope-Data-Storage-Memory-Downloading-and-Uploading-Data )
✔Tell Unistellar that you participated
To know who participated, please tell us your name, serial number and if you agree that your name is mentioned in the EURASTER report on their website (knowing that the GPS coordinates of your observation will be published too).
By filling this survey : https://www.surveymonkey.com/r/H2NDRQC
⚠️ Please, fill this survey⚠️
We will only analyze data from this survey
You have now accomplished your mission. Our scientists thank you and hope you enjoyed it.
We will publish the occultation results soon on EURASTER and on our website.
It is a small step for you, and a big step for science.
If you need help or if you have any questions or remarks, don’t hesitate to contact us by e-mail : firstname.lastname@example.org