Bryant Grigsby

Sealing a small asteroid within an enclosure enables innovative approaches
to the Asteroid Redirect Mission concept that pave the way for
future in situ asteroid resource utilization. A sealed enclosure would
make it possible to use an introduced atmosphere of xenon gas to
detumble and despin the asteroid, and then to push the asteroid by
using a steady xenon gas flow inside this enclosure to transfer the force
of the spacecraft’s exterior solar electric propulsion engine to… Show more

Sealing a small asteroid within an enclosure enables innovative approaches
to the Asteroid Redirect Mission concept that pave the way for
future in situ asteroid resource utilization. A sealed enclosure would
make it possible to use an introduced atmosphere of xenon gas to
detumble and despin the asteroid, and then to push the asteroid by
using a steady xenon gas flow inside this enclosure to transfer the force
of the spacecraft’s exterior solar electric propulsion engine to the asteroid.
The gas will affect the cohesion forces of the asteroid, but the
differential pressures exerted on the asteroid and surface regolith will be
much less than the expected combined cohesion forces of weakly
consolidated rubble piles and fragile primitive asteroids, which are of
prime scientific interest for planetary defense and origin-of-life studies.
That makes it possible to bring such a weakly consolidated asteroid
mostly intact to the Earth–Moon system. Once released into lunar orbit,
a small intact asteroid can be a viable proving ground for manned
missions to more distant and larger asteroids in solar orbit. The development
of this technology will benefit future asteroid resource utilization
operations, in which enclosures are essential for providing
protection from loose regolith and dust, capturing volatiles from icy
objects, and enabling the use of reactive gasses in processing the asteroid
material. Show less

The Cameras for Allsky Meteor Surveillance (CAMS) video-based meteoroid orbit
survey adds 60 newly identified showers to the IAU Working List of Meteor
Showers (numbers 427, 445–446, 506–507, and part of 643–750). 28 of these are also
detected in the independent SonotaCo survey. In total, 230 meteor showers and
shower components are identified in CAMS data, 177 of which are detected in at
least two independent surveys. From the power-law size frequency distribution of
detected… Show more

The Cameras for Allsky Meteor Surveillance (CAMS) video-based meteoroid orbit
survey adds 60 newly identified showers to the IAU Working List of Meteor
Showers (numbers 427, 445–446, 506–507, and part of 643–750). 28 of these are also
detected in the independent SonotaCo survey. In total, 230 meteor showers and
shower components are identified in CAMS data, 177 of which are detected in at
least two independent surveys. From the power-law size frequency distribution of
detected showers, we extrapolate that 36% of all CAMS-observed meteors
originated from ~700 showers above the N = 1 per 110,000 shower limit. 71% of
mass falling to Earth from streams arrives on Jupiter-family type orbits. The
transient Geminids account for another 15%. All meteoroids not assigned to
streams form a sporadic background with highest detected numbers from the apex
source, but with 98% of mass falling in from the antihelion source. Even at large ~7-
mm sizes, a Poynting-Roberson drag evolved population is detected, which implies
that the Grün et al. collisional lifetimes at these sizes are underestimated by about a
factor of 10. While these large grains survive collisions, many fade on a 104
-y
timescale, possibly because they disintegrate into smaller particles by processes
other than collisions, leaving a more resilient population to evolve.
The meteors assigned to the various showers are identified in the CAMS Meteoroid
Orbit Database 2.0 submitted to the IAU Meteor Data Center, and can be accessed
also at http://cams.seti.org. Show less

During routine low-light level video observations with CAMS (Cameras for
All-sky Meteor Surveillance) in June of 2011, four Daytime Arietid
meteors were triangulated during the hour before dawn. The measured
orbital elements are in good agreement with the linked orbit of the
Marsden Sunskirter group comet C/1999 J6 = C/2004 V9 = P/2010 H3. Unlike
results from past radar observations of this daytime shower, and prior
less accurate multi-station video observations, there… Show more

During routine low-light level video observations with CAMS (Cameras for
All-sky Meteor Surveillance) in June of 2011, four Daytime Arietid
meteors were triangulated during the hour before dawn. The measured
orbital elements are in good agreement with the linked orbit of the
Marsden Sunskirter group comet C/1999 J6 = C/2004 V9 = P/2010 H3. Unlike
results from past radar observations of this daytime shower, and prior
less accurate multi-station video observations, there is no longer a
discrepancy in semi-major axis. This result firmly establishes the
association of the Daytime Arietids with the Marsden Sunskirter group of
comets. Show less

First results are presented from a newly developed meteoroid orbit
survey, called CAMS - Cameras for Allsky Meteor Surveillance, which
combines meteor detection algorithms for low-light video observations
with traditional video surveillance tools. Sixty video cameras at three
stations monitor the sky above 31° elevation. Goal of CAMS is to
verify meteor showers in search of their parent comets among newly
discovered near-Earth objects.This paper outlines the concept of… Show more

First results are presented from a newly developed meteoroid orbit
survey, called CAMS - Cameras for Allsky Meteor Surveillance, which
combines meteor detection algorithms for low-light video observations
with traditional video surveillance tools. Sixty video cameras at three
stations monitor the sky above 31° elevation. Goal of CAMS is to
verify meteor showers in search of their parent comets among newly
discovered near-Earth objects.This paper outlines the concept of
operations, the hardware, and software methods used during operation and
in the data reduction pipeline, and accompanies the data release of the
first batch of meteoroid orbits. During the month of November 2010, 2169
precisely reduced meteoroid trajectories from 17 nights have an error in
the apparent radiant of the trajectory <2° and error in speed
<10%. Median values of the error are 0.31° and 0.53 km/s,
respectively, sufficient to resolve the intrinsic dispersion of annual
meteor showers and resolve minor showers from the sporadic background.
The limiting visual magnitude of the cameras is +5.4, recording meteors
of +4 magnitude and brighter, bright enough to stand out from the mostly
fainter sporadic meteors detected as under dense radar echoes.CAMS
readily detected all established showers (6) active during the clear
nights in November. Of the showers that needed confirmation, we confirm
the theta Aurigids (THA, IAU#390), the chi Taurids (CTA, IAU#388), and
the omicron Eridanids (OER, IAU#338). We conclude that the iota November
Aurigids (IAR, IAU#248) are in fact the combined activity of the theta
Aurigids and chi Taurids, and this shower should be dismissed from the
list. Finally, there is also a clustering consistent with the zeta
Cancrids (ZCN, IAU#243), but we cannot exclude that this is lower
perihelion dust belonging to the Orionid shower.Data are submitted to
the IAU Meteor Data Center on a semi-regular basis, and can be accessed
also at http://cams.seti.org. Show less

During routine low-light level video observations with CAMS (Cameras for
Allsky Meteor Surveillance) in the period April 26 - May 7, we detected
the April Rho Cygnids (ARC), a meteor stream discovered by the Canadian
Meteor Orbit Radar (CMOR) project in the years 2002 - 2009. The stream
is included in the IAU Working list of Meteor Showers as shower #$348,
awaiting verification. CMOR data show ARC activity from April 25 - May
4, peaking on April 28. We detected this… Show more

During routine low-light level video observations with CAMS (Cameras for
Allsky Meteor Surveillance) in the period April 26 - May 7, we detected
the April Rho Cygnids (ARC), a meteor stream discovered by the Canadian
Meteor Orbit Radar (CMOR) project in the years 2002 - 2009. The stream
is included in the IAU Working list of Meteor Showers as shower #$348,
awaiting verification. CMOR data show ARC activity from April 25 - May
4, peaking on April 28. We detected this shower on all dates, peaking on
April 28 and May 1 in 2011. The orbital parameters we found match the
CMOR data. Our mean orbital elements are (N = 29): q = 0.844+-0.034 AU,
1/a = 0.18+- 0.10 1/AU, i = 69.7+-2.8 deg, omega = 130.4+-6.2 deg, and
Omega = 39.9+-2.9. The parent body of the ARC remains unknown, but from
the recent evolution of the stream, we provide a range of possible
current orbits. Show less

CBET 2817 available at Central Bureau for Astronomical Telegrams.

The images in our data set were acquired using the 0.76m KAIT and the 1m
Nickel telescope, both at Lick Observatory located on Mt. Hamilton just
outside of San Jose, CA. The site typically has an average seeing of
~2", with some seasonal dependence. We make an effort to
spectroscopically classify and monitor newly discovered SNe with time
allocated to us on the 3m Shane telescope at Lick Observatory using the
Kast double spectrograph.

We present BVRI light curves of 165 Type Ia supernovae (SNe Ia) from the
Lick Observatory Supernova Search follow-up photometry program from 1998
through 2008. Our light curves are typically well sampled (cadence of
3-4 days) with an average of 21 photometry epochs. We describe our
monitoring campaign and the photometry reduction pipeline that we have
developed. Comparing our data set to that of Hicken et al., with which
we have 69 overlapping supernovae (SNe), we find… Show more

We present BVRI light curves of 165 Type Ia supernovae (SNe Ia) from the
Lick Observatory Supernova Search follow-up photometry program from 1998
through 2008. Our light curves are typically well sampled (cadence of
3-4 days) with an average of 21 photometry epochs. We describe our
monitoring campaign and the photometry reduction pipeline that we have
developed. Comparing our data set to that of Hicken et al., with which
we have 69 overlapping supernovae (SNe), we find that as an ensemble the
photometry is consistent, with only small overall systematic
differences, although individual SNe may differ by as much as 0.1 mag,
and occasionally even more. Such disagreement in specific cases can have
significant implications for combining future large data sets. We
present an analysis of our light curves which includes template fits of
light-curve shape parameters useful for calibrating SNe Ia as distance
indicators. Assuming the B - V color of SNe Ia at 35 days past maximum
light can be presented as the convolution of an intrinsic Gaussian
component and a decaying exponential attributed to host-galaxy
reddening, we derive an intrinsic scatter of σ = 0.076 ±
0.019 mag, consistent with the Lira-Phillips law. This is the first of
two papers, the second of which will present a cosmological analysis of
the data presented herein. Show less

The University of California (UC) began operating the Lick Observatory
onMount Hamilton, California in 1888. Nearly a century later, UC became
a founding partner in the establishment of theW. M. Keck Observatory
(WMKO) in Hawaii, and it is now a founding partner in the Thirty Meter
Telescope (TMT) project. Currently, most UC-affiliated observers conduct
the majority of their ground-based observations using either the Keck
10-meter Telescopes on Mauna Kea or one or more… Show more

The University of California (UC) began operating the Lick Observatory
onMount Hamilton, California in 1888. Nearly a century later, UC became
a founding partner in the establishment of theW. M. Keck Observatory
(WMKO) in Hawaii, and it is now a founding partner in the Thirty Meter
Telescope (TMT) project. Currently, most UC-affiliated observers conduct
the majority of their ground-based observations using either the Keck
10-meter Telescopes on Mauna Kea or one or more of the six Lick
telescopes now in operation on Mount Hamilton; some use both the Keck
and Lick Telescopes. Within the next decade, these observers should also
have the option of observing with the TMT if construction proceeds on
schedule. During the current decade, a growing fraction of the
observations on both the Keck and Lick Telescopes have been conducted
from remote observing facilities located at the observer's home
institution; we anticipate that TMT observers will expect the same. Such
facilities are now operational at 8 of the 10 campuses of UC and at the
UC-operated Lawrence Berkeley National Laboratory (LBNL); similar
facilities are also operational at several other Keck-affiliated
institutions. All of the UC-operated remote observing facilities are
currently dual-use, supporting remote observations with either the Keck
or Lick Telescopes. We report on our first three years of operating such
dual-use facilities and describe the similarities and differences
between the Keck and Lick remote observing procedures. We also examine
scheduling issues and explore the possibility of extending these
facilities to support TMT observations.
Show less

At the University of California's Lick Observatory, we have implemented
an on-sky testbed for next-generation adaptive optics (AO) technologies.
The Visible-Light Laser Guidestar Experiments instrument (ViLLaGEs)
includes visible-light AO, a micro-electro-mechanical-systems (MEMS)
deformable mirror, and open-loop control of said MEMS on the 1-meter
Nickel telescope at Mt. Hamilton. (Open-loop in this sense refers to the
MEMS being separated optically from the wavefront… Show more

At the University of California's Lick Observatory, we have implemented
an on-sky testbed for next-generation adaptive optics (AO) technologies.
The Visible-Light Laser Guidestar Experiments instrument (ViLLaGEs)
includes visible-light AO, a micro-electro-mechanical-systems (MEMS)
deformable mirror, and open-loop control of said MEMS on the 1-meter
Nickel telescope at Mt. Hamilton. (Open-loop in this sense refers to the
MEMS being separated optically from the wavefront sensing path; the MEMS
is still included in the control loop.) Future upgrades include
predictive control with wind estimation and pyramid wavefront sensing.
Our unique optical layout allows the wavefronts along the open- and
closed-loop paths to be measured simultaneously, facilitating comparison
between the two control methods. In this paper we evaluate the
performance of ViLLaGEs in openand closed-loop control, finding that
both control methods give equivalent Strehl ratios of up to ~ 7% in
I-band and similar rejection of temporal power. Therefore, we find that
open-loop control of MEMS on-sky is as effective as closed-loop control.
Furthermore, after operating the system for three years, we find MEMS
technology to function well in the observatory environment. We construct
an error budget for the system, accounting for 130 nm of wavefront error
out of 190 nm error in the science-camera PSFs. We find that the
dominant known term is internal static error, and that the known
contributions to the error budget from open-loop control (MEMS model,
position repeatability, hysteresis, and WFS linearity) are negligible. Show less

The Kuiper belt is a collection of small bodies (Kuiper belt objects,
KBOs) that lie beyond the orbit of Neptune and which are believed to
have formed contemporaneously with the planets. Their small size and
great distance make them difficult to study. KBO 55636 (2002
TX<SUB>300</SUB>) is a member of the water-ice-rich Haumea KBO
collisional family. The Haumea family are among the most highly
reflective objects in the Solar System. Dynamical calculations… Show more

The Kuiper belt is a collection of small bodies (Kuiper belt objects,
KBOs) that lie beyond the orbit of Neptune and which are believed to
have formed contemporaneously with the planets. Their small size and
great distance make them difficult to study. KBO 55636 (2002
TX<SUB>300</SUB>) is a member of the water-ice-rich Haumea KBO
collisional family. The Haumea family are among the most highly
reflective objects in the Solar System. Dynamical calculations indicate
that the collision that created KBO 55636 occurred at least 1Gyr ago.
Here we report observations of a multi-chord stellar occultation by KBO
55636, which occurred on 9 October 2009 UT. We find that it has a mean
radius of 143+/-5km (assuming a circular solution). Allowing for
possible elliptical shapes, we find a geometric albedo of in the V
photometric band, which establishes that KBO 55636 is smaller than
previously thought and that, like its parent body, it is highly
reflective. The dynamical age implies either that KBO 55636 has an
active resurfacing mechanism, or that fresh water-ice in the outer Solar
System can persist for gigayear timescales. Show less

We report on a successful occultation of a star by Pluto that was
observable over much of the south and western United States. The
centerline was close to WIRO. We will present seven complete lightcurves
from Crossley/Lick, WIRO, SBO/CU, Palomar, JPL/TMO, Sierra Stars Obs.,
and Magdalena Ridge Observatory. We have 2 partial lightcurves from
Lowell Obs. and McDonald Obs. where data loss was caused by clouds.
There were attempts at the Steward 90", George Observatory, and… Show more

We report on a successful occultation of a star by Pluto that was
observable over much of the south and western United States. The
centerline was close to WIRO. We will present seven complete lightcurves
from Crossley/Lick, WIRO, SBO/CU, Palomar, JPL/TMO, Sierra Stars Obs.,
and Magdalena Ridge Observatory. We have 2 partial lightcurves from
Lowell Obs. and McDonald Obs. where data loss was caused by clouds.
There were attempts at the Steward 90", George Observatory, and New
Mexico Skies that were clouded out. The UCF station near Orlando was
clearly an appulse. A number of other amateurs also succeeded in
collecting data. Our presentation will provide a final geometric
solution for the event as well as baseline fits to the atmospheric
structure. This work was supported by NASA Planetary Astronomy grants
NNX08AO626 and NNX08AO50G. Show less

We attempt to linearize the output of the Shack-Hartmann wavefront
sensor in the ViLLaGEs instrument. ViLLaGEs (Visible Light Laser
Guidestar Experiments) is a MEMS-based Adaptive Optics system on the 1 -
meter Nickel telescope at Lick Observatory meant to provide correction
at visible wavelengths with a 9x9 subaperture Hartmann sensor. We
estimate that the open-loop accuracy of ViLLaGEs is ~40 nm. We
"calibrate" the Hartmann linearity by raster scanning a tip/tilt… Show more

We attempt to linearize the output of the Shack-Hartmann wavefront
sensor in the ViLLaGEs instrument. ViLLaGEs (Visible Light Laser
Guidestar Experiments) is a MEMS-based Adaptive Optics system on the 1 -
meter Nickel telescope at Lick Observatory meant to provide correction
at visible wavelengths with a 9x9 subaperture Hartmann sensor. We
estimate that the open-loop accuracy of ViLLaGEs is ~40 nm. We
"calibrate" the Hartmann linearity by raster scanning a tip/tilt mirror
downstream of an internal fiber and inverting the resulting signal,
forming a lookup table of unbiased tilts. From this calibration, we
conclude that nonlinearity is a minor effect in the open-loop operation
of ViLLaGEs, on the order of ~15 nm. We show through simulations of
Shack-Hartmann sensors that this error is likely due to an internal
pupil mask not physically conjugate to the telescope pupil. We test the
resulting lookup table on an internal "turbulator" in ViLLaGEs, or a
rotating plate meant to simulate the wind-driven atmosphere, and find
that the Strehls with and without the lookup table are
indistinguishable. Show less

We describe a project to enable remote observing on the Nickel 1-meter
Telescope at Lick Observatory. The purpose was to increase the
subscription rate and create more economical means for graduate- and
undergraduate students to observe with this telescope. The Nickel
Telescope resides in a 125 year old dome on Mount Hamilton. Remote
observers may work from any of the University of California (UC) remote
observing facilities that have been created to support remote work… Show more

We describe a project to enable remote observing on the Nickel 1-meter
Telescope at Lick Observatory. The purpose was to increase the
subscription rate and create more economical means for graduate- and
undergraduate students to observe with this telescope. The Nickel
Telescope resides in a 125 year old dome on Mount Hamilton. Remote
observers may work from any of the University of California (UC) remote
observing facilities that have been created to support remote work at
both Keck Observatory and Lick Observatory. The project included
hardware and software upgrades to enable computer control of all
equipment that must be operated by the astronomer; a remote observing
architecture that is closely modeled on UCO/Lick's work to implement
remote observing between UC campuses and Keck Observatory; new policies
to ensure safety of Observatory staff and equipment, while ensuring that
the telescope subsystems would be suitably configured for remote use;
and new software to enforce the safety-related policies. The results
increased the subscription rate from a few nights per month to nearly
full subscription, and has spurred the installation of remote observing
sites at more UC campuses. Thanks to the increased automation and
computer control, local observing has also benefitted and is more
efficient. Remote observing is now being implemented for the Shane 3-
meter telescope. Show less

Visible Light Laser Guidestar Experiments (ViLLaGEs) is a new
Micro-Electro Mechanical Systems (MEMS) based visible-wavelength
adaptive optics (AO) testbed on the Nickel 1-meter telescope at Lick
Observatory. Closed loop Natural Guide Star (NGS) experiments were
successfully carried out during engineering during the fall of 2007.
This is a major evolutionary step, signaling the movement of AO
technologies into visible light with a MEMS mirror. With on-sky Strehls
in… Show more

Visible Light Laser Guidestar Experiments (ViLLaGEs) is a new
Micro-Electro Mechanical Systems (MEMS) based visible-wavelength
adaptive optics (AO) testbed on the Nickel 1-meter telescope at Lick
Observatory. Closed loop Natural Guide Star (NGS) experiments were
successfully carried out during engineering during the fall of 2007.
This is a major evolutionary step, signaling the movement of AO
technologies into visible light with a MEMS mirror. With on-sky Strehls
in I-band of greater than 20% during second light tests, the science
possibilities have become evident. Described here is the advanced
engineering used in the design and construction of the ViLLaGEs system,
comparing it to the LickAO infrared system, and a discussion of Nickel
dome infrastructural improvements necessary for this system. A
significant portion of the engineering discussion revolves around the
sizable effort that went towards eliminating flexure. Then, we detail
upgrades to ViLLaGEs to make it a facility class instrument. These
upgrades will focus on Nyquist sampling the diffraction limited point
spread function during open loop operations, motorization and automation
for technician level alignments, adding dithering capabilities and
changes for near infrared science. Show less

Contributing author and adviser. Wrote many "Consultant's Corner"