Transcript Save the Sky: Adventures in Sky Monitoring

The Night Sky Live Project
PI: Robert J. Nemiroff
& The Night Sky Live Collaboration
The Night Sky Live Project
Web address: http://NightSkyLive.net
People:
Faculty: Noah Bosch (Tel Aviv U.), Wellesley
Pereira (Michigan Tech), J. Bruce Rafert
(Clemson), John Oliver (Florida)
Graduate students: Lior Shamir (MTU), Shet Tilvi
(MTU)
Undergraduate students (MTU): Dan Cordell, Vic
Muzzin, Matt Merlo
The Night Sky Live Project
CONCAM: Hardware
CONCAMs are essentially fisheye lenses
attached to CCDs run by a PC computer and
connected to the internet. CONCAMs do not
move - they are completely passive.
Most simply put: light comes in the top, electricity comes in
the bottom, and data flow out the bottom.
In building CONCAMs, we have three
montras:
“If it moves, it breaks.”
“The lens IS the dome.”
“Don’t spend 90% of your time trying to get 10% more
images.”
The Night Sky Live Project
Three General Objectives
Primary Science
Temporal monitoring and archiving of entire visible sky down
to visual magnitude 6. Search for meteors, unusual stellar
variability, GRB OTs, comet variability, novae, supernovae,
etc.
Support Science
Instantaneous cloud monitors, archival cloud monitors,
generate real-time all-sky opacity maps and skyglow maps
Education / Outreach
Show your class last night’s (real) sky, archival skies,
monitor meteor showers in real time, show educational sky
movies, run educational modules
The Night Sky Live Project
CONCAM Locations
Ten NSL nodes are currently deployed -- more are being built
The Night Sky Live Project
Four of the Eight CONCAM locations
Kitt Peak
Mauna Kea
Mt. Wilson
Wise Obs.
The Night Sky Live Project
Data Policy
All recent images are available through
http://NightSkyLive.net
All data are free and public domain.
All FITS and JPG data are archived to DVDs
(previously CDs).
Each CONCAM takes a new all-sky frame
every 3m56s.
Higher level data products (e.g. photometry)
now generated in real time for most
CONCAMs and displayed on the NSL web site
The Night Sky Live Project
Three General Objectives
Primary Science
Temporal monitoring and archiving of entire visible sky down
to visual magnitude 6. Search for meteors, unusual stellar
variability, GRB OTs, comet variability, novae, supernovae,
etc.
Support Science
Instantaneous cloud monitors, archival cloud monitors,
generate real-time all-sky opacity maps and skyglow maps
Education / Outreach
Show your class last night’s (real) sky, archival skies,
monitor meteor showers in real time, show educational sky
movies, run educational modules
The Night Sky Live Project
Scientific Milestones (so far)
First CCD device to image the position of a gamma-ray burst during the
time of the gamma-ray burst trigger (#1: GRB 001005)
Most complete, global, and uniform coverage of a meteor storm: the
2001 Leonids
Most complete light curves for hundreds of bright variable stars starting
from May 2000, when the first CONCAM was deployed on Kitt Peak.
First devices to give real-time optical ground truth for the whole sky in
support of major astronomical telescopes, including Gemini North,
Keck, Subaru, IRTF, SpaceWatch, Wise, ING 4-m, Mayall 4-M, SARA,
and WIYN.
Since May 2003, fisheye night sky webcams now image most of the
night sky, most of the time. For example, were SN 1987A to go off
tomorrow, there would be a good chance that a CONCAM saw it.
The Night Sky Live Project
Primary Science: Variable Stars
How stable are stars? How stable is our Sun?
CONCAM frames see all bright stars with visual
magnitude > 6
New measurement every 3 minutes 56 seconds
24 hours monitoring
Automatic photometry tables generated for stars with
visual magnitudes > 3
Has detected binary star occultations and pulsations
Can detect flares, planetary occultations, novae
The Night Sky Live Project
Primary Science: Variable Stars
The Night Sky Live Project
Primary Science: Meteors
Did meteors provide Earth with its organic
materials?
Where do meteors come from?
CONCAMs see bright meteors: fireballs with visual mag> -1.
Global network gives the most complete coverage of known
meteor showers.
Observes sporadic meteors when no other professional
instrument is looking.
Obtains photometric information superior to film.
Dual CONCAMs on Hawaii’s Mauna Kea (Big Island) and
Haleakala (Maui) allow 3D determination of meteor path and
origin.
The Night Sky Live Project
Primary Science: Meteors
The Night Sky Live Project
Primary Science: Meteors
Altitude: start: 98.00 km end: 82.47 km
Ground distance of end from HL: 149.7 km; Ground distance of end from MK: 94.2 km
Absolute distance of end from HL: 171.7 km; Absolute distance of end from MK: 125.2 km
Ground distance of start from HL: 154.29 km; Ground distance of start from MK: 96.4 km
Absoulte distance of start from HL: 185.01 km; Absolute distance of start from MK: 137.48 km
start of trial altitude: 98.00 km; end of trial altitude: 82.47 km
Total Length of trail: 16.2 km; Ground distance from beginning to end of trail: 4.6 km
angle towards earth: 73.45; zenith of the start of the trial:
long=-154.890; lat=20.470
zenith of the end of the trial:
long=-154.930
lat=20.481
estimated location of collision with earth (at sea level):
longitude=-154.871
latitude=20.693
Ground distance of meteor trail until collision with earth=24.5 km
estimated source of the meteor:
RA=5.467
DEC=36.54
The Night Sky Live Project
Primary Science: Meteors
The Night Sky Live Project
Primary Science: Transients
When do transients occur?
What optical variability occurs in the
early/bright parts of celestial explosions?
Continuous sky monitoring obtains images for all
optical transients with mag < 4.
Confirmed no bright OT to many GRBs.
Goal: find and trigger on bright new transients.
Problem: hard to find in background of cosmic rays,
clouds, satellite glints, variable stars, and meteors.
The Night Sky Live Project
Primary Science: Transients
The Night Sky Live Project
Three General Objectives
Primary Science
Temporal monitoring and archiving of entire visible sky down
to visual magnitude 6. Search for meteors, unusual stellar
variability, GRB OTs, comet variability, novae, supernovae,
etc.
Support Science
Instantaneous cloud monitors, archival cloud monitors,
generate real-time all-sky opacity maps and skyglow maps
Education / Outreach
Show your class last night’s (real) sky, archival skies,
monitor meteor showers in real time, show educational sky
movies, run educational modules
The Night Sky Live Project
Support Science: Skyglow
Real time (“cloudy”) image computationally
compared with “clear” image taken on a
previous night at the same sidereal time
All PSFs removed (clear and cloudy images)
leaves “star-free” background images
gives raw skyglow for both images in mag/arcsec2
cloudy / clear image counts divided
gives relative skyglow between clear and cloudy
The Night Sky Live Project
Support Science: All-Sky Opacity Maps
Photometry done for hundreds of stars
Both for cloudy and clear frames
Given the relative skyglow map, there is a
unique solution for relative sky opacity at any
star location
Opacity map generated by going pixel-topixel, weighted averaging the opacity of
nearest ten stars
The Night Sky Live Project
Support Science: Skyglow and Opacity
Generated for only CONCAM3s at present
Regenerated every 3m56s for all locations
Accurate to about 0.1 magnitudes broadband
Reasons for skyglow
airglow, light pollution, zodiacal light, moon glow,
cloud reflection.
Reasons for opacity
clouds, aerosols (dirty air), airplane contrails
The Night Sky Live Project
Clear sky frame
Cloudy frame being analyzed. The
image was taken at the same sidereal
time but on another night.
The Night Sky Live Project
Clear sky frame
Cloudy frame being analyzed. The
image was taken at the same sidereal
time but on another night.
The Night Sky Live Project
Raw cloudy frame
Opacity map superimposed in blue.
Thin sub-visual clouds become apparent.
The Night Sky Live Project
Raw skyglow map. Baseline
skyglow is set to 21 mag/arcsec2
Relative skyglow map between clear
and cloudy frames, in mag/arcsec2
The Night Sky Live Project
Support Science: Usefulness
Real time pointing decisions for major telescopes
Real time run / don’t run decisions for robotic
telescopes
site evaluation for current major telescopes sites
site evaluation for potential future telescope sites
light pollution evaluation for current telescope sites
increases photometric accuracy for telescopes at
CONCAM locations
The Night Sky Live Project
Three General Objectives
Primary Science
Temporal monitoring and archiving of entire visible sky down
to visual magnitude 6. Search for meteors, unusual stellar
variability, GRB OTs, comet variability, novae, supernovae,
etc.
Support Science
Instantaneous cloud monitors, archival cloud monitors,
generate real-time all-sky opacity maps and skyglow maps
Education / Outreach
Show your class last night’s (real) sky, archival skies,
monitor meteor showers in real time, show educational sky
movies, run educational modules
The Night Sky Live Project
Education and Outreach
1000s of page views every night.
Learning modules online
variable stars
diurnal motion
Real time and archival viewing
tonight’s sky
meteor showers
lunar eclipses
The Night Sky Live Project
Support
NSF CAREER ($200K)
NSF CCLI ($85K)
NSF ITR ($45K)
Site support grants ($20K):
Canary Islands
South Africa
Cerro Pachon (Chile)
Haleakala
The Night Sky Live Project
Support