Nano-Jasmin: ESA to participate in Japan's mini-Hipparchos?

Japan's National Observatory is planning to launch a 35kg astrometric satellite, dubbed Nano-Jasmin, to do astrometry at the very bright end. The idea might be: if ESA provides the launch, the the "Gaia team" will get access to the data. Ask Coryn what he knows about this...

LSST in Germany

After conversation with Steve Kahn, Michael Strauss (& at end -- Joe Mohr)

Basic plan:

get a DPG (not the whole community) going, which involves the usual suspects
and enough university participation that a DFG Schwerpunkt, as suggested by Krückeberg,
seems feasible..

DFG Schwerpunkt, deadline Oct 15; decision by March; Rundgespräch recommended


HWR's action to coordinate within the MPG:

-draft e-mail with the basic options:
Who want's to commit how many "individual slots"
Should we cast this is terms of a joint MPG participation group?
Should we approach the MPG Präsidium for central funds?

What do spectra tell us about age (that is not encased in [Fe/H], [a/Fe])?

just a note to be brought up with Melissa, to commit to memory until she's back from Michigan:

Basis: Cannon trained with 5 labels, with ages from Kepler; with the Cannon, we get "age" recovered as a parameter with +-2 Gyrs. BUT: to which extent is the age just a corollary of [a/Fe] and [Fe/H]?

[FromMarie's work, we KNOW that there's more information ...]

Plan to find out:
Application of the age label (as is) to the DR12  RC sample, yields <age>([Fe/H],[a/Fe]);

let's define   D(age)_Kepler  == age_Kepler - <age>([Fe/H],[a/Fe])  and
                    D(age)_Cannon  == age_Cannon - <age>([Fe/H],[a/Fe])
and plot

                  D(age)_Kepler vs  D(age)_Cannon  (as opposed to age_Kepler vs age_Cannon),
i.e. we look at a version of the age vs age plot, compressed around the mean age at a given abundance.

If the Cannon teaches us nothing new about ages beyond that which could be known from
[Fe/H] and [a/Fe], we should get a scatter plot.

HWR's conjecture: the extent along the 1-to-1 line will be ~2 times the scatter..; so, there is more in the spectra...

Should Euclid make 2 passes around the sky?

At the moment, Euclid's wide (15k sqdeg) survey will take all of its data on a given patch
of the sky in one pass (few hours), with some field overlap at the edges.

If the overhead penalty is defensible, it may be conceivable to make two passes around
the sky, taking half the exposure time at each, with the passes separated by ~1 year.

One of the things to think about is which aspects of the time-domain science are enabled by this?

Supernovae? Proper motions of very nearby, very red objects? AGN?


Steps (HWR) for June meeting:

take Mark Cropper's draft of alternate survey strategies, and get Bob Scaramella's
documentation on the survey strategy.

Get Jason involved (weak lensing), Bob Nichol (large scale structure),

Goal:  -- provide the scope document
-- lay out which impact needs to be to be considered:

-- what is the impact of the alternate strategies on the
    basic area-S/N- considerations

-- impact on data reduction, data release policy

-- impact on weak-lensing and LSS science

Distant halo giants using PS1 (incl. proper motions)

Can we use PS1 & (who else?) WISE colors to identify distant halo giants,
using PS1 to weed-out proper motions?
We want tip-of-the-RGB stars that are bright enough for good follow-up, i.e. m_r<19.5,
which should also provide good PM constraints.
What are the candidate source densities?

Things to be checked:
   -- to what distance do we reach with such constraints
   -- what IR photometry coverage do we have and how useful are these colors
   -- what PM do we expect?
   -- probably use either galaxy or Besancon models to explore
 

Value-added information in the APOGEE survey to get stellar ages

This issue came up in the context off what Gaia and Apogee synergies could hold, and in particular on the question of whether Apogee should change its targeting strategy or observation sequence to get better age information.
The two avenues I have pursued are:
 -Observations and targeting of stars on the sub giant-branch with Apogee
 -Repeat observations of giants within 2 parsecs, to compliment astrometric binary orbit solutions with two epoch velocities; A good orbit solution would yield a direct dynamical estimate of the giant mass, thereby constraining its age.

Next actions:
HWR should do estimates over holiday break, so as to present initial results at Seattle, Jan 9, 2015.

Define directions a low latitude

Look up APOGEE target selection criteria

get Besancon models for such criteria

estimate dynamical orbit distances and parallax accuracies

Hypervelocity stars in PS1

Reminded by http://arxiv.org/abs/1411.5022
(which is not immediately applicable): we should check
for high-velocity stars towards the bulge....

Possible next steps are as follows:
Devise an LSD quest that finds candidates. Possible selection criteria could be:
-- within 30° off the bulge
-- at a photometric distance consistent with the bulge
-- certain number of epochs with good photometry
A well-measured proper motion that is consistent with three epochs and
implies a velocity above 300 km per second.