Accepted Cycle 12 Observing Proposals

STARS & WD

Proposal Number	Subject Category	PI Name	Title
12200013	STARS AND WD	Wood	Exploring the Spectral Type Dependence of Coronal Abundance Anomalies
12200107	STARS AND WD	Ribas	Calibrating the time-evolution of the high-energy emissions of GKM stars: key to modeling exoplanet atmospheres
12200121	STARS AND WD	Costantini	Hunting debris disks with Chandra
12200128	STARS AND WD	Townsley	A Long Look at NGC 3603, the Milky Way's Starburst Cluster
12200141	STARS AND WD	Stelzer	X-ray emission from wide brown dwarf binaries
12200156	STARS AND WD	Ayres	Alpha Cen to the Max
12200172	STARS AND WD	Riaz	Testing the effects of X-ray emission on brown dwarf disks
12200185	STARS AND WD	Schmitt	Maunder Minimum stars: How frequent are they ?
12200197	STARS AND WD	Poppenhaeger	Making planetary transits visible in X-rays
12200214	STARS AND WD	Povich	A Search for Diskless Young Stars in M17's Heart of Darkness
12200241	STARS AND WD	Oskinova	Understanding the weak winds: high-resolution Chandra spectroscopy of mu Col
12200324	STARS AND WD	Schulz	Magnetic Activity in Very Young O-Stars
12200393	STARS AND WD	Agueros	Searching for Millisecond Pulsars in Extremely Low-Mass White Dwarf Binaries
12200423	STARS AND WD	Wolk	The V380 Orionis Star Forming Region
12200492	STARS AND WD	Kashyap	SPINNING CORONA OF FK COM
12200501	STARS AND WD	Corcoran	Monitoring Mass Loss from Eta Carinae With the HETG: Apastron
12200553	STARS AND WD	Guenther	Can Weakly Magnetized Herbig Ae Stars Drive Fast X-ray Jets?
12200639	STARS AND WD	Guinan	An X-ray Study of The Red Dwarf Next Door: The Long-Term Activity of Proxima Cen
12200640	STARS AND WD	Kastner	X-rays from Planetary Nebulae: Unveiling Binarity, Magnetic Fields, and Wind Collisions
12200645	STARS AND WD	Wolk	The Cat's Other Paw: Star Formation in a Frothy Bottom
12200712	STARS AND WD	Sacco	The origin of the X-ray emission from the enigmatic multiple system HBC 515
12200733	STARS AND WD	Lisse	Characterizing the X-ray Radiation Field in the Earth-like Planet Forming ExoSystem HD 113766
12200735	STARS AND WD	Chu	A 30: A Case Study of Mass-Loading
12200772	STARS AND WD	Wang	Rosette: Understanding Star Formation in Molecular Cloud Complexes
12200774	STARS AND WD	Brown	CHANDRA X-RAY AND HST/COS+STIS UV SPECTROSCOPY OF LOW-MASS STARS IN THE 9 MYR OLD TW HYA ASSOCIATION
12200807	STARS AND WD	Wright	Testing 'Collect and Collapse' Triggered Star Formation Models in DR15
12200811	STARS AND WD	Schneider	What is the nature of HH~2's X-ray emission?
12200817	STARS AND WD	Forbrich	Circumstellar disk heating II: linking stellar X-ray flares with IR disk afterglows on timescales from hours to months
12200870	STARS AND WD	Guinan	Chandra X-ray Observations of Our Nearest Solar Twin - 18 Sco: How Well Does Its Coronal Properties Match the Sun?
12200904	STARS AND WD	Saar	Magnetically Sleepy Stars: An X-ray Survey of Candidate Stars in Extended Magnetic Minima

Subject Category: STARS AND WD

Proposal Number: 12200013

Title: Exploring the Spectral Type Dependence of Coronal Abundance Anomalies

PI Name: Brian Wood

We propose to improve our empirical understanding of how coronal abundance anomalies, such as the solar "FIP effect," vary with spectral type by observing the X-ray spectra of Pi3 Ori (F6 V) and GJ 338 (M0 V+K7 V) with LETGS. No high resolution X-ray spectrum has ever been taken of a coronal main sequence star with a spectral type as early as that of Pi3 Ori. A known correlation between spectral type and FIP effect suggests that Pi3 Ori's X-ray spectrum should show the strongest solar-like FIP effect ever observed. The observation of the GJ 338 binary will efficiently provide two stellar spectra in one exposure, which we will use to test whether stars with modest coronal activity can possess an "inverse FIP effect," a phenomenon generally associated only with very active stars.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
04:49:50.40	+06:57:40.50	Pi3 Ori	HRC-S	LETG	80
09:14:22.80	+52:41:11.80	GJ 338	HRC-S	LETG	100

Subject Category: STARS AND WD

Proposal Number: 12200107

Title: Calibrating the time-evolution of the high-energy emissions of GKM stars: key to modeling exoplanet atmospheres

PI Name: Ignasi Ribas

A key element to understand planetary atmospheres (Solar System and exoplanets) is the time-evolution of the flux at short wavelengths (X-rays to UV) of the host stars, having direct impact on important questions related to photochemistry and evaporation. While the high-energy flux evolution is well understood for solar-type stars, this is not the case of the later K and M stars. The Chandra observations will allow us to build X-ray luminosity versus age calibrations by sampling the critical intermediate-age interval (1-4 Gyr). This is done by measuring KM stars in wide binary pairs with white dwarf companions that we use as chronometers to determine reliable ages. The time-variation of coronal temperature will provide additional diagnostics useful to both exoplanets and dynamo theory.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
05:55:43.80	+46:50:52.70	NLTT15797	ACIS-S	NONE	10
03:28:49.00	-27:19:02.30	LP888-63	ACIS-S	NONE	5

Subject Category: STARS AND WD

Proposal Number: 12200121

Title: Hunting debris disks with Chandra

PI Name: Elisa Costantini

We propose to observe the X-ray bright star AU Mic using the HRC-I camera with the goal of detecting and studying the X-ray scattered light of the well known debris disk around this object. For the first time the study of the dust content in a progenitor of a planetary system will be studied in the X-rays. This is a unique experiment that can only be performed using Chandra.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
20:45:09.50	-31:20:27.20	AU Microscopii	HRC-I	NONE	25

Subject Category: STARS AND WD

Proposal Number: 12200128

Title: A Long Look at NGC 3603, the Milky Way's Starburst Cluster

PI Name: Leisa Townsley

NGC 3603 is one of the youngest truly massive stellar clusters in the Galaxy and serves as a springboard for understanding super star clusters such as R136 in 30 Doradus. Recent advances in infrared imaging and UV/visual spectroscopy applied to NGC 3603 are yielding new catalogs of pre-Main Sequence stars and new spectral types for massive stars; advances in ACIS analysis techniques now give robust X-ray source properties in crowded fields that facilitate comparison with these new datasets. We will apply these new methods to a deep ACIS-I observation of NGC 3603 to study its massive stars (3 W-R + >100 O stars, including over half of the Galaxy's O3 stars), thousands of pre-main sequence stars, and diffuse X-ray emission that pervades the cluster, perhaps indicating cavity supernovae.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
11:15:07.20	-61:15:35.20	NGC 3603	ACIS-I	NONE	460

Subject Category: STARS AND WD

Proposal Number: 12200141

Title: X-ray emission from wide brown dwarf binaries

PI Name: Beate Stelzer

Wide binary brown dwarfs offer a unique opportunity to study similarities and differences of substellar objects that were born and have evolved together. They also represent an efficient way to search for relations of brown dwarf X-ray emission with bolometric luminosity, effective temperature, and mass, yielding two points in the parameter space at one shot. Only four wide binary brown dawrfs are known in various star forming regions. We have observed and resolved two of them (2M1101-7732 and FUTau) with Chandra with surprising results, and propose here to observe the remaining two (Oph1622-2405 and UScoCTIO108).

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
16:22:25.20	-24:05:13.90	Oph1622-2405	ACIS-S	NONE	60

Subject Category: STARS AND WD

Proposal Number: 12200156

Title: Alpha Cen to the Max

PI Name: Thomas Ayres

Nearby Alpha Centauri contains the two best characterized G and K dwarfs, next to the Sun itself, thanks to the accurate orbit, resolved angular diameters, and well understood co-evolutionary state. Alpha Cen A & B also have the best studied stellar X-ray activity cycles, extending back to the 1970's. In fact, Chandra LETGS spectra of the double star are superior to any existing solar material in the crucial 2-20 nm band, accounting for bulk of Sun's XUV emission (relevant to Space Weather). Present proposal is to continue the evolving coronal narrative with dual HRC-I pointings in Cycle 12, and an LETGS spectrum of the sun-like pair close to the peaks of their X-ray cycles. STIS FUV spectra will leverage the coronal line measurements (e.g., dynamics and low-T B.C. for DEM modeling).

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
14:39:30.40	-60:49:59.60	Alpha Centauri	HRC-S	LETG	80
14:39:30.40	-60:49:59.60	Alpha Centauri	HRC-I	NONE	5
14:39:30.40	-60:49:59.60	Alpha Centauri	HRC-I	NONE	10

Subject Category: STARS AND WD

Proposal Number: 12200172

Title: Testing the effects of X-ray emission on brown dwarf disks

PI Name: Basmah Riaz

We request Chandra observations for a sample of young (~1-5 Myr) brown dwarf disks in the Taurus and Upper Scorpius star-forming regions. The strength in the X-ray emission among young brown dwarfs is found to be (weakly) correlated to the crystallization and grain growth processes occurring in the disks, such that objects that are strong X-ray emitters (logLx ~ 29.5 ergs/s) show strong signs of grain growth but negligible signs of crystallinity, while crystallization is found to be more prominent (with negligible signs of grain growth) among the weaker X-ray sources (logLx ~ 28 ergs/s). We propose to observe in X-rays a sample of such extreme cases, and to further probe the dependence of these dust processing mechanisms on X-ray emission among sub-stellar disks.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
04:41:48.20	+25:34:30.40	2M04414825	ACIS-S	NONE	35
04:24:26.50	+26:49:50.30	CFHT-BD-Tau 9	ACIS-S	NONE	35

Subject Category: STARS AND WD

Proposal Number: 12200185

Title: Maunder Minimum stars: How frequent are they ?

PI Name: Jurgen Schmitt

The exceptional low activity of the Sun during the Maunder minimum period between 1650 - 1715 is still an unsolved astrophysical puzzle; the appearance of solar activity during that period is of major interest for solar physicists, for climatologists, and for astrophysicists. Various searches for stellar analogs of the Maunder minimum Sun have had only mixed success, and it is controversial how common Maunder minimum stars really are. We propose to carry out a sensitive X-ray survey of extremely low activity stars in the solar neighborhood to investigate whether these stars are characterized by very low coronal temperatures as found for solar coronal holes and whether these stars are indeed ''flat-activity'' objects rather than showing cyclic behavior as the Sun.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
00:25:45.00	-77:15:15.00	Gl 19	ACIS-S	NONE	5
03:09:04.00	+49:36:48.00	Gl 124	ACIS-S	NONE	5
00:44:39.00	-65:38:58.00	Gl 31.5	ACIS-S	NONE	15

Subject Category: STARS AND WD

Proposal Number: 12200197

Title: Making planetary transits visible in X-rays

PI Name: Katja Poppenhaeger

We propose to observe the planet-bearing star HD 189733 for 120ks, split into eight pointings of 15ks each. The pointings will cover the planetary transit with 6.3ks duration as well as some timespan before or after the transit. Our primary interest lies in the behaviour of hardness ratios versus countrates. Close-in planets with extended atmospheres are expected to have larger X-ray radii compared to optical measurements, adding up to 20% occultation area in the case of HD 189733. The transits are expected to cause significant outliers in hardness ratio vs. countrate plots, because the transit lowers the countrate, but not the hardness ratio. Our observations will give observation-based estimates for planetary radii in X-rays for the first time, which is crucial for evaporation scenarios.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
20:00:43.70	+22:42:36.40	HD 189733	ACIS-S	NONE	120

Subject Category: STARS AND WD

Proposal Number: 12200214

Title: A Search for Diskless Young Stars in M17's Heart of Darkness

PI Name: Matthew Povich

We propose a 100-ks ACIS-I observation of a large (~100 pc long) molecular cloud complex associated with the giant H II region M17. The dense, central regions appear as filamentary infrared dark clouds containing >200 embedded intermediate-mass young stellar objects (YSOs) in Spitzer images; this is a rare example of a young proto-OB association. ACIS will detect a few hundred disk-dominated YSOs plus potentially hundreds of diskless young stars associated with the cloud. We may also detect hard X-ray emission and possibly soft, diffuse emission associated with ultracompact H II regions in the ACIS field. Our results will provide new constraints on circumstellar disk lifetimes, timescales for OB star formation, and the current star formation rate in the complex.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
18:18:17.40	-16:53:20.10	M17 Infrared Dark Cloud	ACIS-I	NONE	100

Subject Category: STARS AND WD

Proposal Number: 12200241

Title: Understanding the weak winds: high-resolution Chandra spectroscopy of mu Col

PI Name: Lidia Oskinova

The action of X-rays is commonly invoked to explain the winds of low-luminosity O-type stars. These stars have significantly smaller mass-loss rate than predicted by the theory of radiation-driven winds. In this respect they may resemble supermassive stars in the early universe, which presumably had weak winds due to their low metallicity. We propose to obtain the first high-resolution X-ray spectrum of a weak-wind O star. The LETGS spectrum of mu Col will allow to discriminate between possible mechanisms for the generation of X-rays and help to resolve the weak-wind problem. Chandra observations of mu Col will establish a gauge for the stellar wind theory and provide a template X-ray spectrum of a massive star with weak wind, such as typical for low metallicity environment.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
05:45:59.90	-32:18:23.20	mu Col	HRC-S	LETG	250

Subject Category: STARS AND WD

Proposal Number: 12200324

Title: Magnetic Activity in Very Young O-Stars

PI Name: Norbert Schulz

We propose HETGS observations of the central massive stars in the RCW 38 cluster in order to obtain the highly resolved spectrum of the young massive star IRS2. The O-star is of type O5 star and thus likely a very young protagonist for the prototype O-star Zeta Pup. We will compare the spectra of this star to very young massive stars in the Orion Trapezium Cluster and the hypothesis that very young massive stars are X-ray weak unless magnetically enhanced mostly narrow wind lines. We intend to perform detailed plasma diagnostics using H-, He-, Li- like lines and put the results in perspective with magnetic wind properties, standard shock instabilities as well effects from multiplicity.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
08:59:05.60	-47:30:40.90	IRS2	ACIS-S	HETG	55

Subject Category: STARS AND WD

Proposal Number: 12200393

Title: Searching for Millisecond Pulsars in Extremely Low-Mass White Dwarf Binaries

PI Name: Marcel Agueros

Several apparently isolated extremely low-mass white dwarfs (ELM WDs), with masses <0.2 M_sun, have recently been discovered in optical surveys. These ELM WDs cannot form through the evolution of single stars and are likely to be in double-degenerate systems; several of the previously known ELM WDs are companions of millisecond radio pulsars (MSPs). To distinguish between neutron star (NS) and WD companions, we propose a search for X-ray emission from three ELM WDs for which our optical monitoring suggests that the probability of a >1.4 M_sun companion is >30%. New MSPs with companions amenable to spectroscopy are of great interest, as they allow for a measurement of NS mass, while ruling out NS companions will put constraints on common envelope models for double WD evolution.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
08:22:12.60	+27:53:07.40	SDSS J082212.57+275307.4	ACIS-S	NONE	2
03:45:16.80	+17:48:09.10	NLTT 11748	ACIS-S	NONE	1
08:49:10.10	+04:45:28.70	SDSS J084910.13+044528.7	ACIS-S	NONE	11

Subject Category: STARS AND WD

Proposal Number: 12200423

Title: The V380 Orionis Star Forming Region

PI Name: Scott Wolk

We propose 60 ks ACIS-I observation of the sub cluster near the Herbig Ae/Be star V380 Ori in the Orion A Cloud. Unlike the ONC, this region is has no EUV radiation to effect the evolution of disk systems. In fact the region has limited Far-UV flux, when compared to the Northern part of the Orion A cloud. Our survey with XMM and Spitzer reveals a new ClassIII dominated subcluster around iota Ori - just and north of V380 Ori. While the requested observation will allow the fuller elucidation of the X-rays related to this flow, out primary goals are: 1) Understanding the spatial distribution of young stars 2) Understanding the effect of the UV environment on the evolution of disks and 3) Investigating the effect of X-rays on the disks; including about 10 protostars.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
05:35:42.20	-06:42:49.30	V380 Ori	ACIS-I	NONE	60

Subject Category: STARS AND WD

Proposal Number: 12200492

Title: SPINNING CORONA OF FK COM

PI Name: Vinay Kashyap

FK Com (GIII) is an ultra-fast rotator - a coalesced binary that has spun up - and provides unique insights into activity at the extremes of dynamo action. Two consecutive Chandra orbits of ACIS-S/HETG and 20 orbits of HST/COS observations will be combined with contemporaneous Doppler imaging maps and spectropolarimetric field measurements to build 3D coronal models. We will: locate dominant coronal and TR structures using Doppler shifts; measure emission scale heights via rotational broadening; derive densities, abundances, and EM in both quiescent and flaring plasma; constrain the dynamic processes by line profile modeling; and measure microflaring effects. Results of this LP will provide a detailed legacy view of the workings of coronae at their extreme edge.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
13:30:46.80	+24:13:57.70	FK Com	ACIS-S	HETG	240

Subject Category: STARS AND WD

Proposal Number: 12200501

Title: Monitoring Mass Loss from Eta Carinae With the HETG: Apastron

PI Name: Michael Corcoran

Eta Car is a key object for understanding how mass and angular momentum change as a star heads towards hypernova. Periodic minima in X-rays and other wavebands show it as an extremely eccentric binary with a massive companion. A surprising change in the X-ray emission during the January 2009 X-ray minimum probably indicates a large-scale variation in the system mass loss. X-ray line profiles are the best diagnostic of the wind-wind collision and the structure of the interacting winds. We propose to obtain HETGS spectra of the system during AO12 near apastron, along with STIS mapping which will constrain the 3-D shape of the wind-wind interaction regions on scales of 1--1000AU and help determine the physical mechanism behind the unexpected rise out of X-ray minimum in 2009.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
10:45:03.60	-59:41:04.30	Eta Car	ACIS-S	HETG	110

Subject Category: STARS AND WD

Proposal Number: 12200553

Title: Can Weakly Magnetized Herbig Ae Stars Drive Fast X-ray Jets?

PI Name: Hans Guenther

The radiative Herbig Ae stars are fundamentally different from the convective T Tauri stars (TTS), and yet both drive optical jets. The well-studied nearby Herbig Ae star HD 163296 has a measured weak stellar magnetic field, and indications of X-ray emission in its jet from a previous short Chandra observation. We propose 50 ks Chandra imaging of this unique object to measure the proper motion of the X-ray jet and evaluate its luminosity and temperature. This will reveal if a small, but highly energetic jet component exists and in what respect jets from TTS and Herbig Ae stars differ.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
17:56:21.30	-21:57:21.90	HD 163296	ACIS-S	NONE	50

Subject Category: STARS AND WD

Proposal Number: 12200639

Title: An X-ray Study of The Red Dwarf Next Door: The Long-Term Activity of Proxima Cen

PI Name: Edward Guinan

As the nearest star & outlying member of the alpha Cen system, Proxima Cen has well determined physical properties & an age ~5-6 Gyr. From its mass and late spectral type (M5.5 V), Proxima is expected to be fully convective & have a different dynamo from the Sun. Analysis of years of photometry reveals: P-rot = 83.7-d & an activity cycle of ~7.6 yrs. Also X-ray data from ROSAT, XMM and Chandra show a corresponding coronal X-ray cycle with an expected minimum during 2010/11. We propose an LETGS observation to extend (& better define) its coronal activity cycle. These data will be used to carry out a detailed physical analysis of the changes in its coronal properties over its cycle. We also will search for flares & analyze separately. Supporting photometry and spectroscopy also will be made.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
14:29:42.90	-62:40:46.10	Proxima Cen	HRC-S	LETG	80

Subject Category: STARS AND WD

Proposal Number: 12200640

Title: X-rays from Planetary Nebulae: Unveiling Binarity, Magnetic Fields, and Wind Collisions

PI Name: Joel Kastner

Chandra has yielded unparalleled insight into the processes involved in shaping planetary nebulae (PNe), via the detection of diffuse and/or point-like X-ray sources within PNe. Diffuse X-ray sources, whether due to ``hot bubbles'' or to collimated outflows or jets, allow us to probe the energetic shocks within PN wind interaction regions. Meanwhile, X-ray point sources in PNe provide unique diagnostics of circumstellar magnetic fields, accretion disks, wind shocks, and/or binary companions at PN cores. These results from Chandra's first decade have prompted the community of PN astronomers to propose the first systematic X-ray survey of PNe in the solar neighborhood.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
04:09:17.00	+30:46:33.50	NGC 1514	ACIS-S	NONE	20
03:33:14.60	-25:52:18.00	NGC 1360	ACIS-S	NONE	20
19:59:36.30	+22:43:16.10	NGC 6853	ACIS-S	NONE	20
18:53:35.10	+33:01:45.00	NGC 6720	ACIS-S	NONE	20
21:00:32.50	+54:32:36.20	NGC 7008	ACIS-S	NONE	20
11:14:47.70	+55:01:08.50	NGC 3587	ACIS-S	NONE	20
17:35:41.90	-40:11:26.50	PN Lo 16	ACIS-S	NONE	30
19:18:28.10	+06:32:19.30	NGC 6781	ACIS-S	NONE	30
09:39:09.10	-02:48:32.00	A66 33	ACIS-S	NONE	30
17:13:44.20	-37:06:15.90	NGC 6302	ACIS-S	NONE	30
01:42:19.90	+51:34:31.10	M 76	ACIS-S	NONE	30
19:14:36.40	-02:42:25.00	NGC 6772	ACIS-S	NONE	30
23:25:53.60	+42:32:06.00	NGC 7662	ACIS-S	NONE	30
21:36:53.00	+12:47:19.00	NGC 7094	ACIS-S	NONE	30
17:49:15.20	-20:00:34.50	NGC 6445	ACIS-S	NONE	30
07:25:34.70	+29:29:26.40	NGC 2371	ACIS-S	NONE	30
07:41:50.50	-14:44:07.70	NGC 2438	ACIS-S	NONE	30
19:31:35.10	+09:13:31.40	NGC 6804	ACIS-S	NONE	30
07:09:22.50	-00:48:23.60	NGC 2346	ACIS-S	NONE	30
10:24:46.10	-18:38:32.60	NGC 3242	ACIS-S	NONE	30
21:04:10.90	-11:21:48.30	NGC 7009	ACIS-S	NONE	30

Subject Category: STARS AND WD

Proposal Number: 12200645

Title: The Cat's Other Paw: Star Formation in a Frothy Bottom

PI Name: Scott Wolk

We propose deep a moderately deep (100ks) ACIS-I observation of the southwest "pad" of the Cat's Paw nebula (NGC 6334). The target region has a unique frothy structure seen in the light of Ha and Bracket alpha (via the IRAC [4.5] band) - reminiscent of a turbulent flow. We seek to explore 1) The IMF in high mass clusters - the inability of Spitzer to identify Class III stars and source confusion in the galatic plane requires X-ray selection of low mass stars. 2) The (non) disked nature of the sources ranging from revealed O stars to late-type protostars 3) The nature of turbulent structure which may manifest as diffuse emission.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
17:19:47.10	-36:08:35.00	NGC 6334	ACIS-I	NONE	100

Subject Category: STARS AND WD

Proposal Number: 12200712

Title: The origin of the X-ray emission from the enigmatic multiple system HBC 515

PI Name: Giuseppe Sacco

HBC 515 is a recently discovered, intriguing, multiple pre-main sequence system located in the L1622 molecular cloud and, with an X-ray luminosity of Lx~10^{32} erg/s, it is one of the brightest X-ray sources in Orion. HBC 515 is composed of a very young (age<1 Myr) intermediate-mass (~ 2 M_sun) binary, whose circumstellar disk has already dispersed and a class I/II object surrounded by a thick envelope of gas and dust. It is not clear what physical mechanism has triggered the fast disk dispersal. There are two possibilities: dynamical interaction between the components of the multiple system, or photoevaporation due to its X-ray emission. We propose a 30 ks ACIS-I observation of HBC 515 to pinpoint the sources of its X-ray emission and, thereby, distinguish between these alternatives.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
05:54:03.00	+01:40:21.90	HBC 515	ACIS-S	NONE	30

Subject Category: STARS AND WD

Proposal Number: 12200733

Title: Characterizing the X-ray Radiation Field in the Earth-like Planet Forming ExoSystem HD 113766

PI Name: Carey Lisse

We propose a 100 ksec ACIS-S observation of the 12 Myr old system HD 113766, the site of on-going terrestrial planet formation (Lisse et al. 2008), in order to determine the spectrum of x-ray radiation in the fledgling system, its origin in the stellar coronae and proto-planetary disk, and its potential impact on the nascent planet.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
13:06:35.80	-46:02:02.00	HD 113766	ACIS-S	NONE	40

Subject Category: STARS AND WD

Proposal Number: 12200735

Title: A 30: A Case Study of Mass-Loading

PI Name: You-Hua Chu

Wind mass-loading occurs when a fast, tenuous flow ablates a slow, dense clump, resulting in the mixing of cool material into hot shocked gas. This process is present in many astrophysical settings and may have caused the below-expectation temperatures and X-ray luminosities observed in wind-blown bubbles and planetary nebulae (PNe). The born-again PN A30 has a clumpy, H-poor nebula around its central star. HST images indicate that the clumps are ablated by the fast stellar wind. XMM-Newton observation has detected soft diffuse X-rays in the central 15" region. We request a Chandra ACIS-S3 observation of A30 in order to resolve the diffuse emission from the central star. The X-ray results will help constrain our hydrodynamic model of the PN and atmospheric model of the [WC] central star.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
08:46:53.50	+17:52:45.40	PN A66 30	ACIS-S	NONE	100

Subject Category: STARS AND WD

Proposal Number: 12200772

Title: Rosette: Understanding Star Formation in Molecular Cloud Complexes

PI Name: Junfeng Wang

We propose Chandra imaging of three embedded clusters in the Rosette Molecular Cloud (RMC) complex. With complementary existing Spitzer and FLAMINGOS infrared surveys, the Chandra observation is critical for us to: (1) create a complete census of the young stars in the cloud; (2) study the spatial distribution of the young stars in different evolutionary stages within the RMC and the disk frequency in the embedded clusters; (3) construct X-ray Luminosity Function (XLF) and Initial Mass Function (IMF) for the clusters to examine XLF/IMF variations; (4) elucidate star formation history in this complex.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
06:35:09.10	+03:42:01.00	RMC REFL9	ACIS-I	NONE	35
06:31:48.10	+04:19:31.10	RMC PL1	ACIS-I	NONE	25
06:33:31.10	+04:00:06.70	RMC PL3	ACIS-I	NONE	20

Subject Category: STARS AND WD

Proposal Number: 12200774

Title: CHANDRA X-RAY AND HST/COS+STIS UV SPECTROSCOPY OF LOW-MASS STARS IN THE 9 MYR OLD TW HYA ASSOCIATION

PI Name: Alexander Brown

The TW Hya association (age ~ 9 Myr, distances ~ 50 pc) is the nearest group of young stars with ages < 10 Myr and has stars with both actively accreting and debris disks. Consequently, this association offers special opportunities for studying protoplanetary system evolution. We propose to study 7 low mass TWA members using ACIS-S (4 fields; 75 ksec total) to obtain CCD resolution spectra and the COS+STIS spectrographs (18 HST orbits) to obtain medium resolution FUV and NUV spectra. Using these spectra we will study the temperature/EM distributions of the hot (log T = 4 - 7 K) plasma, examine the flows and turbulence in the hot plasma, and construct the full X-ray/EUV/FUV radiation fields to allow modeling their influence on protoplanetary system physics and chemistry.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
11:21:17.20	-34:46:45.50	TWA13 A+B	ACIS-S	NONE	15

Subject Category: STARS AND WD

Proposal Number: 12200807

Title: Testing 'Collect and Collapse' Triggered Star Formation Models in DR15

PI Name: Nicholas Wright

The aim of this proposal is to investigate the 'collect and collapse' method of triggered star formation and test theoretical predictions of its mechanism and resulting stellar populations. We propose a 40 ks ACIS-I observation of DR15, a young star forming region embedded within an expanding CO shell on the outskirts of the Cygnus X giant molecular cloud. The molecular dynamics of the region suggest it is highly influenced by the nearby massive cluster, Cygnus OB2. These observations will allow us to isolate and characterise the young members of DR15, determine age gradients that will confirm or rule-out the triggering method and compare the stellar distribution with the underlying gas and dust structures. This will provide a detailed test of the 'collect and collapse' triggering method.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
20:32:29.00	+40:15:54.00	DR15	ACIS-I	NONE	40

Subject Category: STARS AND WD

Proposal Number: 12200811

Title: What is the nature of HH~2's X-ray emission?

PI Name: Christian Schneider

We propose to re-observe the Herbig-Haro (HH) object No. 2 for 40 ks with ACIS-S to constrain its temporal evolution. HH 2 is a well studied HH object in the Orion molecular cloud and was the first HH object with detected X-ray emission. As HH objects evolve on time-scales of years, multi-epoch observations are essential to study their physics. HH 2 is ideally suited for a second Chandra pointing due to (a) the long time between the first X-ray observation and the proposed observation, (b), the high proper-motion and (c) the favorable geometry, jet collimation or stellar magnetic fields do not complicate the interpretation. Current theories predict distinct features like proper-motion of the X-ray emitting knots, measurable with the proposed observation allowing to verify or falsify them.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
05:36:25.70	-06:47:15.90	HH 2	ACIS-S	NONE	40

Subject Category: STARS AND WD

Proposal Number: 12200817

Title: Circumstellar disk heating II: linking stellar X-ray flares with IR disk afterglows on timescales from hours to months

PI Name: Jan Forbrich

We propose to study the young cluster GGD 12-15 to test theoretical predictions of X-ray heating in circumstellar disks, leveraging extensive mid-IR light curves to be obtained via our Spitzer Warm Mission program YSOVAR. With contemporaneous X-ray/mid-IR light curves, we will: 1) test if YSO X-ray and mid- IR variability are correlated, indicating that stellar X-rays significantly heat disks, and 2) test if disk accretion rates rise in the days and weeks following stellar X-ray flares, as expected from disk accretion models. Supplementary Spitzer observations will expand the scope of the program to shorter timescales. Ancillary science includes the identification of weak-line T Tauri stars to study their mid-IR variability and the LX-rotation of protostars, using mid-IR periods.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
06:10:50.00	-06:12:00.00	GGD 12-15	ACIS-I	NONE	70

Subject Category: STARS AND WD

Proposal Number: 12200870

Title: Chandra X-ray Observations of Our Nearest Solar Twin - 18 Sco: How Well Does Its Coronal Properties Match the Sun?

PI Name: Edward Guinan

18 Sco is the best, nearest, solar twin that has physical properties, rotation and dynamo-activity close to the Sun's. Ca II HK observations show solar-like chromospheric-emissions displaying an activity cycle of ~12 yrs. XMM X-ray observations were fortuitously obtained during the cycle Max returning Lx ~7.5 x 10^26 ergs/s; = 1-2 MK. We propose a 65 ksec ACS-S observation during the star's activity MIN in 2011. These observations will elucidate the star's coronal behavior at the extremes of its activity & permit a precise comparison to the Sun. The Chandra observation will be supported by continued photometry and Ca II HK observations. Pending approval, complementary HST/COS FUV spectroscopy also will be made to study the star's chromo & transition region line emissions.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
16:15:37.30	-08:22:09.90	18 Sco	ACIS-S	NONE	65

Subject Category: STARS AND WD

Proposal Number: 12200904

Title: Magnetically Sleepy Stars: An X-ray Survey of Candidate Stars in Extended Magnetic Minima

PI Name: Steven Saar

The Sun occasionally slips into periods of extended magnetic quiescence where the normal magnetic cycle largely ceases (e.g., the Maunder minimum). Understanding these episodes is important for understanding non-linear magnetic dynamos and the Earth's radiation budget. We have developed a new method for determining which stars may be in the stellar analog of these magnetic minima. We propose to study five such stars with Chandra ACIS-S. Combined with archival spectra of more stars, we can 1) explore (by proxy) properties of the solar corona in a Maunder-like minimum, 2) determine what stellar properties affect this state, and 3) investigate the coronal product of the residual turbulent dynamo in a solar mass star.

R.A.	Dec.	Target Name	Det.	Grating	Exp.Time
06:53:33.90	-28:32:23.20	HD 50806	ACIS-S	NONE	20
13:46:57.10	+06:21:01.30	HD 120066	ACIS-S	NONE	25
16:01:02.60	+33:18:12.60	HD 143761	ACIS-S	NONE	10
17:20:39.60	+32:28:03.80	HD 157214	ACIS-S	NONE	10
19:12:05.00	+49:51:20.70	HD 179958	ACIS-S	NONE	20

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