| MacArthur Foundation | /files/nwL5ZiClBaEcz0s9i67P | https://macfound.org | ||
| Subaru Telescope | /files/sJ2vW7cOdcDxKCtAOOZs | https://subarutelescope.org | ||
| Google Cloud Platfor | /files/YVoStX0IEmQxTvW2oCeB | https://cloud.google.com |
| Component | Use |
|---|---|
| Control box | Contains the “brains” of the unit, a Raspberry Pi running our POCS software. Also contains the power distribution and control. |
| Camera box | Holds the DSLR camera to take photos of the night sky. Attached to the mount. |
| Mount | Precisely tracks stars so the cameras can take long exposure photos. |
| Pier | A rigid frame for the mount that minimizes vibrations as the mount moves. |
> pocs config get mount
{'brand': 'ioptron',
'commands_file': 'ioptron/v310',
'driver': 'panoptes.pocs.mount.ioptron.cem40',
'model': 'cem40',
'serial': {'baudrate': 115200, 'port': '/dev/ttyUSB0', 'timeout': 0.0},
'settings': {'max_tracking_threshold': 99999,
'min_tracking_threshold': 100,
'non_sidereal_available': True,
'park': {'dec_direction': 'north',
'dec_seconds': 15,
'ra_direction': 'west',
'ra_seconds': 15},
'update_tracking': False}}
> pocs config get mount.serial.port
'/dev/ttyUSB0'
> pocs config set mount.serial.port "/dev/ioptron"
{'mount.serial.port': '/dev/ioptron'}
The IP address for the “panoptes” computer is 192.168.8.210. Note that ”panoptes” was the name given when running the installation script.
The default prompt upon sshing to the control computer
An example of a command line prompt in the shell. Here we have turned off the fans in one command and after returning the result, we are given another prompt to type more commands. The green square is where typed characters wil appear.
If more than one person is connected the screen will resize to the smallest display.
M93 Butterfly Cluster (PAN001, Mauna Loa)
|M31 Andromeda Galaxy (PAN012, Mt. Wilson)
| | ------------------------------------------------------------------------------------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------- | ## Finding targets With a rather large 10° by 15° field of view, PANOPTES units have photographed everything from bright galaxies, nebulae, star clusters, the Milky Way, and even comets! The celestial coordinates for your targets (Right Ascension, abbreviated as RA or α, and Declination, abbreviated as DEC or δ) can be obtained through an astronomical almanac, star charts, or an astronomy app. Note that solar system planets might not be as ideal targets for PANOPTES units, because the large field of view doesn’t offer the magnification necessary to resolve any detail (ie. the rings of Saturn or the cloud patterns on Jupiter). Also note that in POCS, it isn’t currently possible to photograph the Sun (which would require solar filters to protect the camera detectors) or the Moon, as by default POCS has been programmed to avoid these targets. ### Known exoplanet transits \- your unit can also observe known exoplanet transits! \- learn how to pick transits: see [*Using the Swarthmore Transit Finder*](broken://pages/-MEsSv5T-9ObM31c0Qxy#_k4f90i7ad75r) in the Appendix Consider observing transits with the following: | 100% visibility, plus \~an hour before and after |Bright star
(magnitudes \~)
| Elevation | | | ------------------------------------------------ | ---------------------------------------- | --------- | - | ## Observing preparations Once you have a target in mind, quickly run through a checklist similar to the following to get set up before observing. ### 1. Check sky conditions Because the Moon can drastically brighten the night sky, be aware of its current phase (which also determines the time it rises and sets). You can use an online calendar (such as the Lunar Calendar at [timeanddate.com/moon/phases](https://www.timeanddate.com/moon/phases/)) to check this. Depending on how close the Moon is to full, you may have to compensate for extra brightness in your camera’s exposure length later. It can also be helpful to view an hourly forecast of the night’s weather beforehand, to help you plan your time accordingly. Note that [weather.com](https://weather.com/) offers hourly forecasts based on location for many parts of the world. Additionally, if your unit is located nearby an observatory, it’s possible that it has its own weather station or cloud cover webcams that update online. ### 2. Plot star trails *(This step is optional.)* You can use a program like Stellarium ([stellarium.org](https://stellarium.org/)) or iObserve ([apps.apple.com/app/iobserve/id424693907](https://apps.apple.com/app/iobserve/id424693907)) to watch the path your target traces in the sky over time. This will help you get an idea for which part of the sky the target is in, and see how close it is to the Moon. ### 3. Create scheduler file Set up a custom scheduler file for your target(s): in a terminal window on the NUC, change directory to the scheduler directory (at $POCS/resources/targets), then create a new .yaml file using the following scheme to specify observation parameters for each target. |name
Target name: allowed characters include letters, numbers, spaces, and hyphens (-).
position
RA and DEC coordinates formatted in hours-minutes-seconds and degrees-minutes-
seconds, respectively.
priority
An arbitrary number you can set to bias the scheduler toward picking certain targets (optional; default: 100). A relatively larger number = higher priority. Must be greater than 1.
exptime
Exposure time in seconds (optional; default: 120). Take the Moon phase and proximity into account! Note that this can be adjusted while observing.
min\_nexp
Minimum number of exposures to take during the observation (optional; default: 60).
exp\_set\_size
The exposures will be taken in smaller sets of this size (optional; default: 10). The minimum number of exposures (min\_nexp) must be an integer multiple of this size!
Note: An observation may consist of more exposures than min\_nexp but exposures will always come in groups of exp\_set\_size.
|EXAMPLE 1 andromeda.yaml
-
name: Andromeda Galaxy
position: 00h42m44s +41d16m09s
priority: 100
exptime: 120
min\_nexp: 10
exp\_set\_size: 2
EXAMPLE 2 star\_wars.yaml
-
name: Tatooine
position: 11h03m22s +63d09m00s
priority: 100
exptime: 60
min\_nexp: 15
exp\_set\_size: 3
-
name: Arvala-7
position: 03h45m01s -07d15m31s
priority: 100
exptime: 100
min\_nexp: 10
exp\_set\_size: 2
-
name: Alderaan
position: 05h29m47s -01d34m01s
priority: 500
exptime: 120
min\_nexp: 6
exp\_set\_size: 3
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | Tip: in the scheduler .yaml file, use a hyphen (-) on a new line in front of each new target, and hit Tab in front of each parameter to indent it properly. \- add some tips for observing from a light-polluted area (ie. city) \- include illustrative comparison between good and bad sky darkness (ie. mauna loa vs. pasadena) \- camera settings \- approx magnitude ranges ### 4. Update POCS Configuration In the pocs\_local.yaml configuration file under scheduler, change the fields\_file from the survey mode target list to the filename of your new scheduler file, from the previous step. Make sure to also enable the setting for POCS to follow changes to the scheduler file so that you can tweak parameters, such as exposure time, while observing: under scheduler, set check\_file to true. | Tip: the scheduler part of pocs\_local.yaml should now look something like: |scheduler:
check\_file: true
fields\_file: star\_wars.yaml
···
| | --------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------- | After editing the config file, restart the config server: docker restart config-server ## Observing sequence overview A high-level description for starting and fine-tuning observations follows, with links to relevant sections from the [POCS Automated Operation Guide](https://docs.google.com/document/d/1I9lBAuRxitC95ltAhUAyZIoIpXjmorBdYzc3sN6EF14/edit?usp=sharing) and [Appendix](broken://pages/-MEsSv5T-9ObM31c0Qxy#_spvwd62jvhm9) for further instructions. Sample log file excerpts are also included to help you know what to expect and easily recognize important messages. ### 1. Start PEAS and POCS **Start PEAS**, and optionally check that the last readings from the camera board and weather station look OK – see [*Starting PEAS Shell*](https://docs.google.com/document/d/1I9lBAuRxitC95ltAhUAyZIoIpXjmorBdYzc3sN6EF14/edit#heading=h.wqmsbcdgpzfh) for all commands. Then **start POCS** if it’s not already running, or if it hasn’t been restarted since changing the scheduler filename in pocs\_local.yaml – see [*Starting POCS Shell*](https://docs.google.com/document/d/1I9lBAuRxitC95ltAhUAyZIoIpXjmorBdYzc3sN6EF14/edit#heading=h.hjs7birt007n). Make sure to have both PEAS and POCS **log files** visible, as you will need to monitor them for errors now and while you observe. In the POCS log, check that both cameras were detected after running setup\_pocs. For each camera, you’ll see confirmation messages similar to the following as it is connected. (If one or both are not detected, try re-running setup\_pocs.) **SAMPLE POCS LOG OUTPUT** **D0213 05:03:10.384 camera.py] Camera created: Canon00 (XXXXXX) on usb:001,024** **D0213 05:02:52.824 canon\_gphoto2.py] Connecting to camera** **D0213 05:02:52.846 camera.py] Getting output from proc 133** **D0213 05:03:01.305 camera.py] gphoto2 command: \['/usr/local/bin/gphoto2', '--port', 'usb:001,023', '--set-config-index', '/main/action s/viewfinder=1', '--set-config-index** **', '/main/capturesettings/autoexposuremode=3', '--set-config-index', '/main/capturesett** **ings/continuousaf=0', '--set-config-index', '/main/capturesettings/drivemode=0', '--set** **-config-index', '/main/capturesettings/focusmode=0', '--set-config-index', '/main/captu** **resettings/shutterspeed=0', '--set-config-index', '/main/imgsettings/imageformat=9', '-** **-set-config-index', '/main/imgsettings/imageformatcf=9', '--set-config-index', '/main/i** **mgsettings/imageformatsd=9', '--set-config-index', '/main/imgsettings/iso=1', *****(ETC.)*****]**SAMPLE POCS LOG OUTPUT
I0226 07:59:34.831 messaging.py] PANCHAT I'm finding exoplanets!
D0226 07:59:34.832 observatory.py] Getting headers for : Alderaan: 120.0 s exposures in blocks of 10, minimum 60, priority 500
D0226 07:59:35.368 observatory.py] Exposing for camera: Canon00
D0226 07:59:35.377 camera.py] image\_id: PAN012\_358d0f\_20200226T075935
D0226 07:59:35.378 camera.py] Taking 120.0 s exposure on Canon00: /var/panoptes/images/fields/Alderaan/345efg/20200213T050652/20200213T051030.cr2
D0226 07:59:35.401 observatory.py] Exposing for camera: Canon01
D0226 07:59:35.413 camera.py] image\_id: PAN012\_95cdbc\_20200226T075935
D0226 07:59:35.414 camera.py] Taking 120.0 s exposure on Canon01: /var/panoptes/images/fields/Alderaan/01abcd/20200213T050652/20200213T051030.cr2
D0226 08:00:05.923 core.py] Waiting for observing events: 30 seconds elapsed
| |Notice that:
Flip required: target crosses meridian
|No flip required: target stays west of meridian
| | ------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------- | ### Checking FITS exposure with DS9  DS9 ([ds9.si.edu](http://ds9.si.edu/)) is a program that astronomers like to use to view FITS files. Download DS9 for your operating system at: [ds9.si.edu/site/Download.html](http://ds9.si.edu/site/Download.html) Once installed on your computer, click on the FITS file you wish to view. (You may need to right-click select “SAOImageDS9” to be the program to open FITS files by default.) The following is an example of an observation FITS file opened in DS9.  When you move the cursor around the image, the info in the top left corner (Value/counts, RA/Dec, image xy coordinates) will update. (Explain WCS) Also notice that the “counts” value for the stars are higher than those of the surrounding background pixels. The brightness of a pixel on the Canon camera detector is given here in “counts” (as in # of photons recorded). The maximum brightness that can be recorded before the detector becomes saturated is \~13,000 counts. To get count readings for a specific target, go to *Analysis > Name Resolution…* (second option) and type in the object’s name in the window that comes up. Click the *Resolve* button, then on the top menu bar, select *File > Crosshair To* and then *File > Pan To*. The counts for the star will be in the Value box at the top left of DS9.  For an optimal exposure time, the counts on the main target should be around \~7000, but shouldn’t exceed 10,000. The counts for the background should be as low as possible. ### Plate solving with Astrometry.net In astronomy, “plate solving” means figuring out which part of the sky your camera was aimed at, using software to find a match between the pattern of stars in your image and existing star catalogs. Astrometry.net ([nova.astrometry.net](http://nova.astrometry.net/)) is a popular online plate solving tool commonly used by astrophotographers, which can output an image’s exact sky coordinates (RA and DEC) and other information, such as any interesting deep sky objects or planets contained in the field of view. You can upload your images to * Through the web interface, at [nova.astrometry.net/upload](http://nova.astrometry.net/upload), you can upload any jpeg/fits/etc photos to plate solve an image of the sky containing stars. The process will take a few minutes. After it’s done, you can get more information about the photo, such as interesting objects in the field of view # Data Information about our data processing and results. The nightly data for PANOPTES is hosted on our Data Explorer: {% embed url="