Updated January 2012.
Please come talk to me if you have an interest in any of these projects.
These are graduate level projects with some of them more involved and in-depth,
and others appropriate for first year or senior undergrad students
to jump right in to.
Come by if you'd like further explanation or background.
Astrometry in the Orion Nebula Cluster
The ONC is the most famous star forming region in the sky! Although it has been
very well studied, many fascinations remain. HST data taken over several epochs
can be used to determine kinematic membership of individual objects which is
important for many studies. The last work of note on this was by Jones & Walker
in 1988 and we can do a lot better now.
Published data on radial velocities complements the two dimensional proper motions
we would derive here to provide a complete three dimensional picture
of the stellar motions. A further motivation for this study is an improved
understanding of the overall cluster dynamics including velocity dispersion
as a function of stellar mass and apparent age, which connects in with recent
theoretical simulations of star cluster and binary formation.
This project will require quite a bit of organizational skill and would
be great for a motivated and dedicated first-year student or anyone beyond.
A radial velocity search for low mass companions and planets around stars
with known debris disks
This is a synthesis project of existing data taken over the past roughly 8 years
which has already been reduced and analyzed to produce time series
radial velocity measurements. It is just waiting for someone to determine
what is interesting in the data set and write up some papers on stellar,
brown dwarf, and maybe even planetary companions to nearby and young stars.
Go for it!
Young stars are well known variable objects, both photometrically and spectroscopically.
The phenomenon is typically studied at optical wavelengths and the observed variability
is attributed to a combination of chromospheric activity and surface spot phenomenon
(including simple rotation), accretion, and variable circumstellar extinction.
Infrared variability, however, is less well understood. Although some of the above
physical phenomena can also cause infrared variability, at longer wavelengths other
phenomena involving the accretion disk are more prevalent.
See Carpenter et al. 2002, 2001 and also Morales et al. (2011) for background.
I am involved in a project with Spitzer led by John Stauffer to study this,
and there is definitely room for a student-led project to develop from
the fully-reduced data set.
John Carpenter is also on this team and could advise you here as well.
Wide binaries and lithium
The coevality of young stars formed in the same cluster or in
the same binary pair is a common assumption. A recent paper by
Kraus and Hillenbrand (2009) assesses this using the technique
of locating stars on the Hertzsprung Russell diagram. Another
age dating technique involves the depletion of the light element
lithium, which is burned in stars but has not been created since
the initial big bang nucleosynthesis. This project
involves a literature and new data assessment of the constraints
on binary coevality using lithium measurements. A first year student
could take this on.
Stellar activity at 80-100 Myr
Mamajek and Hillenbrand (2009) assessed the utility for stellar age dating
of the R'HK activity index,
which based on the emission cores due to chromospheric activity within
the strong CaII "H" and "K" absorption lines in blue optical spectra.
This project would involve filling a gap in the calibration
which can be rectified through study of R'HK in the Alpha Per cluster.
Existing and yet-to-be-obtained observations will be utilized.
Wide binaries and activity
As above for lithium, we also expect binaries to have roughly
the same activity level. Mamajek and Hillenbrand (2009) showed
the extent to which this is true. However, there are few confounding cases
where the apparent activity levels are very different among binary
pairs. Someone should look into this further, perhaps an industrious
Disk/photoevaporative wind tracers
A new data set from HST/COS (ultraviolet spectrograph)
is arriving along with complementary optical
and near-infrared spectra. One project is to compare the
lines and line profiles that are seen in this spectacular data
to those from theoretical models which predict the atomic
ultraviolet/optical/near-infrared line fluxes in an
irradiated circumstellar disk around a young star.
A relatively well-defined project would be to look at a few stars
and establish which lines from the theory are actually useful from
the observational perspective, and measure the line strengths and widths.
The main collaborator on this project is in good contact with the relevant
theorists so we can get new models run with different parameters
as necessary, and iterate until we can constrain the physics of the situation.
Another project based on the same combined data set is to look at the
wind absorption line profiles, also comparing to models.
Extinction towards young stars
This is a mess waiting for a dedicated someone to come along and sort it all out.
FUV data can give an estimate for the column of HI. NUV and optical data
have metallic lines from the interstellar medium. X-ray measurements
also lead to N(H). And there are optical extinction estimates from
photometry. Together these should be telling us a consistent story.
The data mentioned above can in principle be combined to get some
handle on the UV extinction law and how circumstellar + interstellar dust
towards young stars may be different from that in the more general ISM.
The colors of young stars
and let's discuss what we do and don't know regarding intrinsic
colors and how to place young stars in the HR diagram.
Science with the new P1640 high contrast specto-imaging instrument at Palomar
a direct imaging search for low mass companions and planets around nearby stars.
Postdocs Sasha Hinkley and Justin Crepp are working on this project
but there is probably room for a bright graduate student interested in
learning about adaptive optics and
stellar, substellar, and planetary mass companions to nearby stars.
Current first year student Trevor David has gotten involved in this
Young cluster studies
I have some optical photometric and spectroscopic data sets
from Keck on young star clusters like NGC 2024, NGC 2068 / 2071, LkHa 101,
MWC 1080, NGC 7129, and others. The various elements just need to be
synthesized and written up as much of the hard work collecting and
reducing athe photometry and spectroscopy is already done. The product would
be along the lines of
one of my own papers as a graduate student. This is a good first year project.
I can also think of some projects having to do with 2MASS + Spitzer data
on young clusters, which might be precursor work to spectroscopic studies
with the MOSFIRE instrument that is soon to be delivered to Keck.
There are a number of projects having to do with how we determine
the ages of stars, which isn't as straightforward as you may have
been led to believe from your course work. See
for some background and
for further detailed illustration of the conundrum.
Another relevant article is
If you are interested in taking your own data on a project
involving young stars, nearby stars, or galactic astronomy,
I have lots of ideas for telescope proposals that we can discuss.
Better yet, bring your own ideas!