UVIS auroral
update
Wayne Pryor
<- Recent Book with UVIS cover art
2011 UVIS auroral papers
• Katerina Radioti et al.: Bifurcations of the main auroral ring at Saturn:
ionospheric signatures of consecutive reconnection events at the
magnetopause, submitted to JGR
• Denis Grodent et al.: Small scale structures in Saturn’s auroras, accepted
to JGR.
• Pryor, Rymer et al.: The auroral footprint of Enceladus, published in Nature
• Henrik Melin et al.: Simultaneous Cassini VIMS and UVIS observations of
Saturn’s southern aurora—comparing emissions from H, H2, and H3+ at a
high spatial resolution, submitted to GRL.
• Laurent Lamy et al.: - Multi-instrument radio/UV/IR/and ENA simultaneous
observations of Saturnʼsaurorae- pending
Lamy comparisons: 2009-027
Nature Paper on Enceladus Footprint:
is out!
Noon
-movie shows 5 sequential EUV frames; frames 2, 3, 4 show N footprint where predicted
-figure on the right was suggested as cover art
Auroral PDF “book” just updated this weekauroral images + geometry overlay
• Now covers ODCID-1143 images from 20062011
• Includes 2 recent Hubble campaigns from
Spring 2011
Cassini Planning- Inclination Plot
UVIS Planning Report
for XXM (Solstice Mission, now to 2017)
Alain Jouchoux, UVIS team, is implementing
2 kinds of ORS campaigns with UVIS prime:
AURSTARE: High Phase Angle, mix of UVIS imaging slews and stares for
ISS/VIMS night-side imaging
ISS needs 100-140 degrees phase for auroral imaging
Typical UVIS slew rate is 0.06 mrad/s, 8 s integrations
AURSLEW: Low Phase Angle, mix of UVIS imaging slews and stares for
VIMS dayside auroral imaging.
These are being coordinated with Kevin Baines and Ulyana Dyudina
AURSTARE
• 50% UVIS slewing (slit N-S or E-W), imaging nightside
• 50% UVIS staring at dark limb at 75 N or S for ISS imaging
(sample movie with grid lines at 74 and 78N below)
• ISS wants stars in FOV for limb altitude determination
AURSLEW (Dayside)
• Two types:
• NORMAL: 50/50 mix by time of fast slews for
UVIS (60 microradians/s) imaging and stares
for VIMS imaging
• SLOW: 7 microradians/s slews for joint
simultaneous UVIS/VIMS imaging (new thing!)
Summer Plans
• Poster at MOP on ISS-UVIS comparisons
• Work up HST campaign periods (one period
will be shown next)
• Jacques Gustin will work on this too
UVIS
Nichols
HST
Campaign
April 2011
UVIS views N, repeatedly scans across
oval, upper envelope of points shows
the brightest pixels as a function of time
In the following slides, all are scaled the
same way so colors can be compared.
Day 90
Day 99
2011 Day 90
Bright rotates day to
night……
Day side
Night side
2011 Day 93
2011 Day 95
2011 Day 97
2011 Day 99
Now go to “book”
start at page 175 or so…
ISS-UVIS comparisons
• ISS movie from Ulyana Dyudina
October 2009 ISS observation
Ulyana Dyudina, Andy Ingersoll
Day side
stars
• 472 frames
• 81 hour
• 2 - 3 minute exposures
• Broadband visible wavelengths, no
color information
• Orange aurora is a false color
October 2009 movie (472 frames, 81 hours)
Timing
Day
side of and order
stars of 10
• Length
minutes for bright features like
“Snake”
• “Snake”-like features appear
just twice in 81 hours.
• Curtains reappear on
consecutive Saturn days
Heights and location
curtain
• Image scale is 32 km (20
miles) per pixel stars
• Curtain height is 1,200
kilometers (746 miles) above
the planet's limb.
• Latitude of aurora is about
74° and changes with time by
several degrees.
During ISS movie..
Dawn
Dawn
Dawn
Dawn Planetary
Rotation
rotation
Dusk
Dusk
Dusk
Dusk
Time->
Stationary UVIS slit aligned E-W on Saturn North
Time marches to right.
Diagonal formed from bright spots
(Something bouncing back and forth as Saturn rotates?)
Period like an hour: too long for mirroring electrons. (Slide notes).
Alfven waves bouncing back and forth? Mirroring ions?
Valfven= B/sqrt( 0 ni mi) in SI
Same UVIS data plotted by Greg
Holsclaw:
Night-side, slit aligned E-W, quasi-periodic bursts seen.
Feature rotates, with general brightening over growing local time range
.
bright continuous diagonal
Case that goes with ISS snake
ISS snake at 280T23:00
Last one so far- weak episodic diagonal
Gerard HST STIS FUV campaign
coordination
•
•
•
•
•
•
•
2 HST orbits starting w/ 2011-Jan-28 13:00-14:00
(2011-day 28, spectra were geocorona only)
(reschedule/rerun on March 17- L spectra were ok)
2 HST orbits starting w/ 2011-Apr-17 21:30-22:30
(2011-day 107)
2 HST orbits starting w/ 2011-May-10 12:25-13:30
(2011-day 130)
•
•
•
2011-Jan 28 HST
HST program 10235: Jean-Claude Gerard, PI
Jan 28 2011 (day 28) pointing problem, images, no spectra
Hello,
The first visit (2 orbits) of our HST program 12235 (FUV
spectroscopy of Saturn's aurora) took place on January 28th, with
concurrent UVIS
observations from Cassini. Images were
successfully
taken at the beginning of both
orbits (see appended files) and show a
reasonably
bright aurora.
Following the image, long time-tagged
spectra
should have been taken for which the phase 2 proposal
requested pointing at 50° N, followed by a 3 arcsec slow slew towards
the north to scan the auroral region.
However, the G140L and the
G140M spectra show no
emission feature at all, suggesting that the
pointing of the STIS slit missed the planetary
disk and only observed
the dark space. The
headers indicate that the initial slit position
before the slew started was already 2°-3° off the
disk. Since the slit
was moved northward, further
away from the planet, it never hit the
aurora nor
the disk. Consequently, no aurora, airglow nor reflected
solar radiation was observed, neither in the
G140M nor in the G140L
modes. Only geocoronal Ly-alpha and OI1304-A terrestrial airglow
were
detected (see enclosed files). I sent a request to STScI for an
HOPR to repeat the observations. It has now been approved and the
observations will be repeated as soon as
possible, this time without
parallel Cassini
observations. The cause of the too large offset from
the planet's center applied to the telecope is linked to an inadequate
update of the observing date in the observation planning
software
when using the slew mode of HST. This
was only the 3rd times this
mode was used since
HST started its operations !
I shall keep you
informed when further news are available.
Cheers,
Jean-Claude.
Jan 28, 2011 HST (geocorona only)
UVIS geometry for HST period in 144:
• 2011-028T10:00:00 to 2011-028T21:00:00
UVIS_144SA_AURSTARE001_PRIME
• Phase: 121.1-125.0 degrees
• Range to center: 26.07-23.30 Rs
Notes from Alain Jouchoux on
UVIS_144SA_AURSTARE001_PRIME:
- Used the south pole to
allow ISS to be in the dark.
- The total number of scans is 22
• UVIS
scan
start
and
end
ISS stare position
Sample UVIS 2011 day 28 data
2011-day 107 HST
• obhu21btq_flt_prev_1.png
UVIS geometry for HST period in 147:
• 2011-107T12:28:00 to 2011-107T23:08:00
UVIS_147SA_AURORA001_PRIME
• Phase: 69.4-10.9 degrees
• Range to center: 5.01-9.01 Rs
147 design
•
Wayne,
The pointing design for UVIS_147SA_AURORA001_PRIME is a
little tricky: (1) the UVIS
slit is almost parallel to
the equator, so we have to scan South/North; and (2) the
apparent size of
Saturn is much larger that the slit length
(402 mrad at the start of the request and 222 mrad at
the
end.) That forces us to do 5 South/North scans separated by
30 mrad (VIMS FOV is 32 mrad)
to cover the full oval at the
north pole. So we end up doing only (?) 3 coverages of the
full
oval.
Attached are 6 images showing the starting and ending position
of each 5 individual scans
for each of the 3 full oval scans.
The scan rate is 0.007 mrad/s and the separation between
each
individual scan is 30 mrad.
So: (1) Is that what you want?; (2) The scan moves following
Saturn
rotation. Is that Ok? and (3) North pole or South Pole?
(I did not see if Jean Claude answer. I
assume that observing from
Earth orbit he wants the North pole).
Alain
Start (top) and
end (bottom)
positions for the
5 scans of the
first polar image
Start (top) and
end (bottom)
positions for the
5 scans of the
2nd polar image
Start (top) and
end (bottom)
positions for the
5 scans of the
3rd polar image
Sample UVIS
Data 2011 Day 107
UVIS geometry for HST period in 148
• 2011-130T11:12:00 to 2011-130T13:40:00
UVIS_148SA_AURSTARE002_PRIME
• Phase: 170.4-165.5 degrees (night side)
• Range to center: 7.87-7.08 Rs
2011 Day 130 UVIS Sample Data
Conclusions
• This year we are emphasizing collaborative datataking and then papers:
– ISS/UVIS (correlate events)
– UVIS/VIMS (are the images fundamentally different?)
– STIS/UVIS (complementary spectroscopy/imaging)
In 141:
• 2010-330T22:30:00 2010-331T09:30:00
a .UVIS_141SA_AURSTARE001_PRIME
• Phase 117.9-120.7 degrees
• Range to center 30.08-27.76 Rs
d
In 142
• 2010-353T02:00:00 2010-353T13:00:00
a .UVIS_142SA_AURSTARE001_PRIME
• Phase: 130.4-137.0 degrees
• Range to center: 20.76-17.26 Rs
d
Also in 142
• 2010-357T03:30:00 2010-357T13:30:00
a .UVIS_142SA_AURSLEW001_PRIME
• Phase: 60.9-64.6 degrees
• Range to center: 23.01- 25.59 Rs
d
In 143 there are 2 UVIS Saturn PIEs
• 2011-009T13:06:00 2011-009T22:31:00
a .UVIS_143SA_EUVFUV001_PIE
• 2011-010T10:21:00 2011-010T14:49:00
a .UVIS_143SA_EUVFUV002_PIE
d
d
Also in 144:
• 2011-033T08:24:00 2011-034T02:46:00
a .UVIS_144SA_AURSLEW001_PRIME
• Phase: 60.5-66.6 degrees
• Range to center: 23.22-27.70 Rs
d
Also in 144:
• 2011-034T03:50:00 2011-034T20:34:00
a .UVIS_144SA_AURSLEW002_PRIME
• Phase: 66.9-71.1 degrees
• Range to center: 27.93-31.31 Rs
d
In 145:
• 2011-052T16:30:00 2011-052T21:31:00
.UVIS_145SA_EUVFUV001_PIE
• 2011-053T10:11:00 2011-053T20:36:00
.UVIS_145SA_EUVFUV002_PRIME
• 2011-058T08:12:00 2011-058T18:52:00
.UVIS_145SA_EUVFUV003_PRIME
• 2011-061T13:57:00 2011-062T03:37:00
.UVIS_145SA_EUVFUV004_PRIME
• 2011-063T13:27:00 2011-064T02:07:00
.UVIS_145SA_EUVFUV005_PRIME
d
a
d
a
d
a
d
a
d
a
In 146:
• 2011-078T14:45:00 2011-078T17:45:00
a .UVIS_146SA_EUVFUV001_PIE
• 2011-080T11:52:59 2011-080T18:53:00
a .UVIS_146SA_EUVFUV002_PIE
d
d
Also in 146:
• 2011-081T04:33:00 2011-081T15:33:00
a .UVIS_146SA_AURSLEW001_PRIME
• Phase: 33.7-40.2 degrees
• Range to center: 19.17-22.67 Rs
d
In 147:
• 2011-105T06:00:00 2011-105T17:00:00
a .UVIS_147SA_AURSTARE001_PRIME
• Phase: 123.6-129.8 degrees
• Range to center: 22.67-19.30 Rs
d
Also in 147:
• 2011-111T10:03:00 2011-111T21:03:00
a .UVIS_147SA_AURSLEW001_PRIME
• Phase: 52.7-54.9 degrees
• Range to center: 32.87- 34.84 Rs
In 148:
• 2011-127T01:17:00 2011-127T23:17:00
a .UVIS_148SA_AURSTARE001_PRIME
• Phase: 101.1-107.0 degrees
• Range to center: 31.89- 27.14 Rs
In 149:
• 2011-167T05:58:00 2011-167T20:57:00
a .UVIS_149SA_AURSTARE001_PRIME
• Phase: 105.6- 112.5 degrees
• Range to center: 26.61-22.32 Rs
Also in 149:
• 2011-173T07:42:00 2011-173T18:42:00
a .UVIS_149SA_AURSLEW001_PRIME
• Phase: 20.3-22.8 degrees
• Range to center: 29.25-31.44 Rs
In 150:
• 2011-189T14:54:00 2011-190T01:54:00
a .UVIS_150SA_AURSLEW001_PRIME
• Phase: 82.6-88.9 degrees
• Range to center: 21.77- 18.43 Rs
In 151:
• 2011-210T07:07:00 2011-210T18:07:00
a .UVIS_151SA_AURSLEW001_PRIME
• Phase: 73.1-76.7 degrees
• Range to center: 27.80-25.22 Rs
In 152:
• 2011-237T01:34:00 2011-237T12:34:00
a .UVIS_152SA_AURSLEW001_PRIME
• Phase: 11.4-13.8 degrees
• Range to center: 20.76-23.83 Rs
In 153:
• 2011-253T10:47:00 2011-253T21:47:00
a .UVIS_153SA_AURSLEW001_PRIME
• Phase: 69.2-72.1 degrees
• Range to center: 30.31-27.99 Rs
Also in 153:
• 2011-256T12:00:00 2011-256T18:00:00 d
a .UVIS_153SA_ENAURFOOT001_PRIME
• Phase: 121.9-152.7 degrees
• Range to center: 7.97-4.89 Rs
In 154:
• 2011-273T03:17:00 2011-273T14:17:00
a .UVIS_154SA_AURSLEW001_PRIME
• Phase: 86.9-95.2 degrees
• Range to center: 18.47-14.69 Rs
In 155:
• 2011-290T14:46:00 2011-291T05:46:00
a .UVIS_155SA_AURSLEW001_PRIME
• Phase 82.4-91.5 degrees
• Range to Center 20.88-16.15 Rs
In 156
• 2011-309T01:17:00 2011-309T12:17:00
a .UVIS_156SA_AURSLEW001_PRIME
• Phase: 91.2-102.9 degrees
• Range to center: 16.17-11.94 Rs
Also in 156:
• 2011-312T03:32:00 2011-312T14:32:00
a .UVIS_156SA_AURSLEW002_PRIME
• Phase: 18.6-22.5 degrees
• Range to center: 20.29-23.30 Rs
In 157:
• 2011-327T07:02:00 2011-327T20:24:00
a .UVIS_157SA_AURSTARE001_PRIME
• Phase: 100.1- 132.4 degrees
• Range to center: 12.69-6.49 Rs
Also in 157:
• 2011-329T12:33:00 2011-329T23:33:00
a .UVIS_157SA_AURSLEW002_PRIME
• Phase: 6.89-18.3 degrees
• Range to center: 16.65-20.15 Rs
In 158:
• 2011-345T13:35:00 2011-345T21:45:00
.UVIS_158SA_ENAURFOOT001_PRIME
• Phase: 116.3 to 157.5
• Range to center: 8.66-3.51 Rs
a
Planning-IN-1 submitted