Accepted Cycle 16 Observing Proposals

STARS AND WD

Proposal Number	Subject Category	PI Name	Type	Time (ks)	Title
16200073	STARS AND WD	Guinan	GO	80	The ABCs of the old G1.5V/G2.5V/M4-5V Star System 16 Cygni: Calibrating Coronal X-ray Emission for Old Benchmark Stars
16200075	STARS AND WD	Preibisch	GO	75	Completing the Chandra survey of the Carina Nebula: the cluster NGC 3293
16200105	STARS AND WD	Green	GO	88	Rejuvenation of the Innocent Bystander: Testing Spin-Up in a Dwarf Carbon Star Sample
16200111	STARS AND WD	Naze	LP	350	HD191612 - constraining the structure of a massive magnetosphere
16200155	STARS AND WD	Pooley	TOO	50	Catching an FUor in the Act: Chandra ToO Observations of Extreme Accretion onto Young Stars
16200165	STARS AND WD	Feigelson	GO	60	RCW 38: A Unique Laboratory for the Formation and Dynamics of Young Star Clusters
16200199	STARS AND WD	Hofner	GO	80	A CHANDRA Study of the Massive Protostar IRAS16562-3959
16200225	STARS AND WD	Huenemoerder	GO	150	A Deep X-ray look at a very massive star: HETGS spectroscopy of the blue hypergiant HIP 101364
16200249	STARS AND WD	Poppenhaeger	GO	90	An age-activity calibration for old low-mass stars
16200297	STARS AND WD	Gizis	GO	50	The X-Ray Corona of a Flaring L Dwarf
16200333	STARS AND WD	Czesla	GO	30	The cool corona of HD 209458
16200348	STARS AND WD	Miller	GO	21	Atmospheric heating in an irradiated transiting super-Earth and super-Neptune
16200379	STARS AND WD	Ignace	GO	17	A Study of Colliding Winds in Short Period B Star Binaries
16200403	STARS AND WD	Schneider	GO	130	Challenging accretion models with an HETG observation of T Tau
16200417	STARS AND WD	Townsley	GO	100	Massive Star Generations
16200570	STARS AND WD	Rahman	GO	150	X-Ray Investigation of the Most Luminous OB Association in the Galaxy
16200688	STARS AND WD	Reynolds	GO	10	Characterizing a New Variable Hard X-ray Source in the Planetary Nebula G343.3-0.6
16200744	STARS AND WD	Ayres	GO	60	Alpha Centauri at a Crossroads
16200747	STARS AND WD	Sahai	GO	10	Investigating Active Accretion, Flare Activity and a 50 Million Degree Corona in the cool AGB Star, Y Gem
16200849	STARS AND WD	Guinan	GO	40	The Secret Lives of Cepheids: Are Cepheids X-ray Variables?
16200863	STARS AND WD	Drake	LP	500	The Chandra-Kepler Flare Survey

Subject Category: STARS AND WD

Proposal Number: 16200073

Title: The ABCs of the old G1.5V/G2.5V/M4-5V Star System 16 Cygni: Calibrating Coronal X-ray Emission for Old Benchmark Stars

Type: GO Total Time (ks): 80

PI Name: Edward Guinan

Abstract: 16 Cyg ABC is an important G1V+G2.5V+M4V triple system with a precisely-determined Kepler asteroseismic age = 6.8+/-0.4 Gyr, an excellent parallax (d =21.1pc) and ongoing Ca II HK & uvby photometric monitoring. The G2.5V star also hosts a Jupiter-size planet (Bb). The AB components hold a prominent place in astrophysics for studying the evolution, dynamo activity and coronae of a pair of "future Suns." However, the system has not been detected in X-rays. We propose an 80-ksec ACIS-I exposure to characterize the stellar coronae of these benchmark stars. The observation will also include the dM4 companion to A (16 Cyg C; ~3.6" separation),which ties to our study of M-star coronal evolution over time by providing an Lx-Age anchor-point in the difficult-to-determine old age range of M-stars.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+19:41:50.50	+50:31:17.00	16 Cyg ABC	ACIS-I	None	80.0

Subject Category: STARS AND WD

Proposal Number: 16200075

Title: Completing the Chandra survey of the Carina Nebula: the cluster NGC 3293

Type: GO Total Time (ks): 75

PI Name: Thomas Preibisch

Abstract: We propose to complete and conclude Chandra's investigation of the young star clusters in the Carina Nebula Complex with an observation of the last still un-observed massive cluster, NGC3293. Although NGC3293 is probably the second most massive cluster in the entire complex, its low-mass population is basically unknown. A single ACIS-I pointing will reveal the low-mass cluster members and provide a census of the cluster population and its total mass. This information is urgently needed for the study of the global properties and the history of the Carina Nebula Complex. The Chandra data will also allow us to search for isolated neutron stars that are the remnants of the about 20 supernovae that are thought to have occurred in this cluster and for diffuse X-ray emission.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+10:35:50.00	-58:14:00.00	NGC 3293	ACIS-I	None	75.0

Subject Category: STARS AND WD

Proposal Number: 16200105

Title: Rejuvenation of the Innocent Bystander: Testing Spin-Up in a Dwarf Carbon Star Sample

Type: GO Total Time (ks): 88

PI Name: Paul Green

Abstract: Carbon stars (C>O) were long assumed to all be giants, because only AGB stars dredge up significant carbon into their atmospheres. We now know that dwarf carbon (dC) stars are actually far more common than C giants. These dC stars are hypothesized to have accreted C-rich envelope material from an AGB companion, in systems that have likely undergone a planetary nebula phase, eventually yielding a white dwarf and a dC star that has gained both significant mass and angular momentum. To test whether the X-ray emission strength and spectral properties are consistent with a rejuvenated dynamo, we propose a Chandra pilot study of dCs selected from the SDSS; some have hot white dwarf companions (indicating more recent mass transfer), and all show Balmer emission lines (a sign of activity).

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+15:19:06.00	+50:07:02.90	CBS311	ACIS-S	None	27.9
+09:01:28.30	+32:38:33.60	SDSS J090302.86+385527.4	ACIS-S	None	18.5
+15:48:59.70	+34:18:21.70	SDSS J154859.72+341821.7	ACIS-S	None	16.2
+16:37:18.60	+27:40:26.50	SDSS J163718.64+274026.5	ACIS-S	None	25.9

Subject Category: STARS AND WD

Proposal Number: 16200111

Title: HD191612 - constraining the structure of a massive magnetosphere

Type: LP Total Time (ks): 350

PI Name: Yael Naze

Abstract: We propose, through high resolution spectroscopy, to derive the structure of the magnetically confined winds in HD191612, a prototypical magnetic massive star. In such objects, X-rays arise from the strong shocks between stellar wind flows from opposite hemispheres, guided by the field towards the magnetic equator. While X-ray luminosities of magnetic OB stars are now known and fairly well reproduced by models, this is not the case for the structure (position, velocity, temperature) of the magnetospheric plasma, crucially needed for a deep understanding of magnetism at the top of the main sequence. The unique diagnostics provided by HETG will provide the missing information and, together with existing optical and UV observations, enable the full modeling of prototypical confined winds.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+20:09:28.60	+35:44:01.30	HD191612	ACIS-S	HETG	150.0
+20:09:28.60	+35:44:01.30	HD191612	ACIS-S	HETG	200.0

Subject Category: STARS AND WD

Proposal Number: 16200155

Title: Catching an FUor in the Act: Chandra ToO Observations of Extreme Accretion onto Young Stars

Type: TOO Total Time (ks): 50

PI Name: David Pooley

Abstract: FU Orionis (FUor) outbursts are a transitory rapid accretion phase in the evolution of young stellar objects. We propose to obtain an X-ray spectrum during the rise to peak brightness of an FUor with Chandra. This phase has never been observed in X-rays and could reveal important information about the nature and source of the X-ray emission in these objects. In particular, it would provide a unique test of whether high-velocity jets are formed during the intense accretion event. These jets are expected to form X-ray dissociation regions, and X-ray emission does correlate with outflows from young stellar objects. If these jets only exist during the high levels of accretion during the rise to peak brightness, as they are thought to, X-ray observations during this time are crucial.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
		FUor Outburst	ACIS-S	None	50.0

Subject Category: STARS AND WD

Proposal Number: 16200165

Title: RCW 38: A Unique Laboratory for the Formation and Dynamics of Young Star Clusters

Type: GO Total Time (ks): 60

PI Name: Eric Feigelson

Abstract: Most stars form in rich clusters that quickly dissipate into field stars. The theory of cluster expansion and dynamical ejection of stars has few empirical constraints today. RCW 38 is a unique young star cluster seen at a critical juncture in its history just after the expulsion of molecular gas by massive stars during its brief stage of expansion and non-equilibrium dynamics. It has the densest core of any star cluster near the Sun with unequilibrated spatial structure. We proposed a 100 ks exposure (part GO and part GTO) to be combined with the archived 100 ks and improved near-infrared data. The known cluster population should triple to 2000 stars; star masses and ages will be estimated. RCW 38 will give a superb empirical foundation for understanding cluster early evolution.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+08:59:05.50	-47:30:40.00	RCW 38	ACIS-I	None	60.0

Subject Category: STARS AND WD

Proposal Number: 16200199

Title: A CHANDRA Study of the Massive Protostar IRAS16562-3959

Type: GO Total Time (ks): 80

PI Name: Peter Hofner

Abstract: The formation of massive stars remains a challenge to astrophysics. X-ray observations are important, but only a small number of massive potostars have been observed, all of them with B-type star luminosities. In cycle 14 we carried out a short (5ks) observation toward the newly discovered massive protostar IRAS16592-3959 to varify detectability. IRAS16592-3959 is the most luminous protostar known (O8) , and we have clearly detected this object. Here we propose an 80 ks ACIS-I observation with the following science goals: 1) Obtain a higher S/N spectrum of the protostar including Fe line detection and search for flare like variability, 2) Search for X-ray emission form the radio jets, and 3) together with 2MASS and Spitzer data determine the cluster environment of the massive protostar.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+16:59:41.60	-40:03:43.60	IRAS 16562-3959	ACIS-I	None	80.0

Subject Category: STARS AND WD

Proposal Number: 16200225

Title: A Deep X-ray look at a very massive star: HETGS spectroscopy of the blue hypergiant HIP 101364

Type: GO Total Time (ks): 150

PI Name: David Huenemoerder

Abstract: We propose to obtain an ACIS-S/HETGS spectrum of one of the most massive and luminous stars in the Galaxy: the blue hypergiant (B3Ia+) HIP 101364. This star is a representative member of the class of very massive stars. The new observations will result in the first measurement of X-ray spectral lines and their ratios in a blue hypergiant and allow for a comparative analysis of X-ray properties between massive stars at different but related evolutionary stages: luminous blue variables, Wolf-Rayet stars, and blue hypergiants stars. Except for the latter, high resolution X-ray spectra already exist for all other types. The analysis of new data will provide a new understanding of how the most massive stars shed mass during their pre-supernova evolution.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+20:32:41.00	+41:14:29.20	HIP 101364	ACIS-S	HETG	150.0

Subject Category: STARS AND WD

Proposal Number: 16200249

Title: An age-activity calibration for old low-mass stars

Type: GO Total Time (ks): 90

PI Name: Katja Poppenhaeger

Abstract: Low-mass stars are highly interesting targets: we are able to detect planets in their habitable zones, and upcoming searches for biomarkers in exoplanet atmospheres will focus on low-mass star systems due to their ubiquity and proximity. We aim to develop an age-activity calibration for old low-mass stars, using wide binary systems consisting of an M or K dwarf and a white dwarf. The age of the system is determined by the WD cooling time plus its progenitor lifetime, yielding reliable ages in the regime >1 Gyr. For an exploratory sample of 7 systems where we have already derived ages, we propose to perform Chandra ACIS-S observations to determine the X-ray luminosities of the M dwarfs and correlate their stellar activity with age. We ask for a total observing time of 110 ks.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+07:57:43.40	+28:06:45.00	2MASS 07574337+2806456	ACIS-S	None	15.0
+11:08:06.50	-05:13:47.20	GJ 1142 A	ACIS-S	None	15.0
+11:45:55.90	+31:49:29.90	NLTT28469	ACIS-S	None	20.0
+23:54:00.70	-33:16:29.90	L577-71	ACIS-S	None	15.0
+23:43:52.90	+32:35:37.80	LP347-5	ACIS-S	None	10.0
+01:23:15.90	-02:08:44.80	NLTT4616	ACIS-S	None	15.0

Subject Category: STARS AND WD

Proposal Number: 16200297

Title: The X-Ray Corona of a Flaring L Dwarf

Type: GO Total Time (ks): 50

PI Name: John Gizis

Abstract: We propose the first observation to determine both the X-ray luminosity and white light flare of a L-type dwarf star. Late-M and L dwarfs show a remarkable drop in chromospheric and coronal activity levels, but surprisingly strong radio emission, a change is that neither fully understood theoretically. Observations are needed to establish empirical relationships and compare to those of warmer flare stars. Kepler observations have already measured the flare rate, and we now propose Chandra observations. We will be able to test the hypothesis that the X-ray corona scales with the flare rate, and compare the relative X-ray, radio, chromosphere and flare energy budget. The target,WISEP J190648.47+401106.8, is uniquely suited for this project because of the Kepler data.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+19:06:48.50	+40:11:06.80	WISEP J190648.47+401106.8	ACIS-S	None	50.0

Subject Category: STARS AND WD

Proposal Number: 16200333

Title: The cool corona of HD 209458

Type: GO Total Time (ks): 30

PI Name: Stefan Czesla

Abstract: We propose to measure the soft X-ray emission of the planet host-star HD 209458 using a 30 ks Chandra HRC-I snapshot. The transiting hot Jovian HD 209458b is one of only two exoplanets with a reliably detected expanded atmosphere and has become a cornerstone of planetary research. Although current models predict that stellar X-ray and extreme ultraviolet irradiation is crucial for the formation of the expanded atmosphere and possibly resulting mass-loss, it has so far eluded detection in HD 209458. The proposed observation will enable us to measure the soft stellar X-ray emission, calculate the level of planetary X-ray and EUV irradiation, compute the mass-loss and compare it to previous measurements, and provide a highly desired constraint for planetary model atmospheres.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+22:03:10.80	+18:53:03.50	HD 209458	HRC-I	None	30.0

Subject Category: STARS AND WD

Proposal Number: 16200348

Title: Atmospheric heating in an irradiated transiting super-Earth and super-Neptune

Type: GO Total Time (ks): 21

PI Name: Brendan Miller

Abstract: We propose Chandra observations of HD 97658 (13 ks) and HAT-P-11 (8 ks) to determine the high-energy radiation incident upon their short-period transiting planets. HD 97658 b is a hot super-Earth with a density between Earth and ice giants, while HAT-P-11 b is a hot super-Neptune orbiting an active K4 star. Measurement of the stellar X-ray (and UV; we contribute Swift time) luminosities provides a current epoch estimate of atmospheric heating and constrains whether these planets are likely to experience significant mass loss through atmospheric evaporation over their total lifetimes. These observations provide essential empirical input for understanding and modeling the potential evolutionary transformation of hot gas giants into less massive and more dense remnants.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+11:14:33.20	+25:42:37.40	HD 97658	ACIS-S	None	13.0
+19:50:50.20	+48:04:51.10	HAT-P-11	ACIS-S	None	8.0

Subject Category: STARS AND WD

Proposal Number: 16200379

Title: A Study of Colliding Winds in Short Period B Star Binaries

Type: GO Total Time (ks): 17

PI Name: Richard Ignace

Abstract: We request 17 ksec to measure the X-ray emissions from two B+B binaries: AH Cep and CW Cep. These are short period, double-lined spectroscopic, eclipsing binaries, and so all fundamental orbital and stellar parameters are known. All 4 stars in these 2 binaries are B0.5V stars of nearly equal mass. Given estimates for mass loss and wind speeds, the respective colliding wind shocks should be adiabatic and located midway between the components. These stars have never been detected in X-rays. Based on the scaling of LX = 1e-7 LBol, we anticipate X-rays from B star winds. We expect detection of the colliding wind shock as signified by a relatively high hardness ratio and excess X-ray brightness; if so, this would be an exciting first detection of colliding wind X-rays from a B+B binary.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+22:47:52.90	+65:03:43.70	AH Cep	ACIS-I	None	10.0
+23:04:02.20	+63:23:48.70	CW Cep	ACIS-I	None	7.0

Subject Category: STARS AND WD

Proposal Number: 16200403

Title: Challenging accretion models with an HETG observation of T Tau

Type: GO Total Time (ks): 130

PI Name: Christian Schneider

Abstract: Young, accreting stars often emit soft X-rays from the accretion shock on the stellar surface. The favored model predicts high densities in the accretion spot compatible with most observations. However, X-ray data of the nearest accreting star (TW Hya) and of the eponymous T Tau show signatures incompatible with shock models. Proposed model modifications require an enhanced density of higher temperature tracers compared to cooler plasma. We propose to test this with a 130 ks HETG observation of T Tau to (a) provide the first significant measurement of its Ne IX triplet (high temperature) to augment XMM-Newton data of the O VII triplet (low temperature) and (b) to search for spatial offsets of the soft X-rays which could explain the lack of accretion signatures in T Tau by jet emission.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+04:21:59.40	+19:32:06.40	T Tau	ACIS-S	HETG	130.0

Subject Category: STARS AND WD

Proposal Number: 16200417

Title: Massive Star Generations

Type: GO Total Time (ks): 100

PI Name: Leisa Townsley

Abstract: This survey extends and enhances Chandra/ACIS studies of massive stars by sampling both very young O stars ionizing ultracompact HII regions (UCHIIRs) and the aged and evolved massive stars in Young Massive Clusters (YMCs). This will double the Chandra sample of UCHIIRs and provide dozens of X-ray spectra on older massive stars. We combine two new ACIS-I pointings with GTO and archival data to achieve an economical study of W42 and W33, nearby massive star-forming regions <1 Myr old, plus the much older and more distant YMCs Cl 1813-178 and Red Supergiant Cluster 1. These sensitive observations will also document pre-main sequence populations and trace the effects of massive star feedback by mapping diffuse X-rays from supernova remnants and wind-shocked plasma.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+18:38:14.60	-06:49:19.00	W42	ACIS-I	None	60.0
+18:14:13.50	-17:55:42.00	W33	ACIS-I	None	40.0

Subject Category: STARS AND WD

Proposal Number: 16200570

Title: X-Ray Investigation of the Most Luminous OB Association in the Galaxy

Type: GO Total Time (ks): 150

PI Name: Mubdi Rahman

Abstract: We propose conducting 150 ks ACIS-I observations of the Galaxy's most luminous OB association, the recently-discovered Dragonfish Association. The observations will enable us to characterize the upper-end of the X-ray luminosity function to determine the membership of the most massive stars within the association. This will provide the first systematic characterization of the association members, impossible through any other means given the large extinguishing column and on-sky contamination. Based on the results of these observations, we will investigate the energetics of this association and how feedback is driven into the interstellar medium.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+12:12:20.10	-63:15:30.90	Dragonfish Association	ACIS-I	None	150.0

Subject Category: STARS AND WD

Proposal Number: 16200688

Title: Characterizing a New Variable Hard X-ray Source in the Planetary Nebula G343.3-0.6

Type: GO Total Time (ks): 10

PI Name: Mark Reynolds

Abstract: We request a 10 ks observation of a new hard X-ray point source associated with the planetary nebula G343.3-0.6. Discovery observations with Swift reveal a bright (f_x >~ 5e-12 erg s^-1 cm^-2) and highly variable source suggesting the presence of an active binary system in this planetary nebula. The proposed Chandra observation will enable us to constrain the X-ray spectral variability and the sub-arcsecond source position will enable the location of the optical/nIR counterpart of this enigmatic source.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+17:01:28.00	-43:05:55.00	G343.3-0.9	ACIS-S	None	10.0

Subject Category: STARS AND WD

Proposal Number: 16200744

Title: Alpha Centauri at a Crossroads

Type: GO Total Time (ks): 60

PI Name: Thomas Ayres

Abstract: Nearby Alpha Centauri (G2V+K1V) contains the two best characterized solar-like dwarf stars, which also have the best studied X-ray activity cycles, extending back to the 1970's. Objective is to continue tracking the evolving multi-decadal high-energy narrative of Alpha Cen with semiannual HRC-I pointings in Cycles 16-18, as the system reaches a coronal crossroads: solar twin A rising toward cycle maximum, K-type companion B sinking into a minimum. HST/STIS UV spectra will support and leverage the X-ray measurements by probing subcoronal dynamics, with connection to the corona through the FUV Fe XII forbidden line. Only Chandra can resolve the AB X-ray sources as the Alpha Cen orbit also reaches a crossroads in 2016.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+14:39:28.30	-60:49:57.20	ALPHA CEN	HRC-I	None	60.0

Subject Category: STARS AND WD

Proposal Number: 16200747

Title: Investigating Active Accretion, Flare Activity and a 50 Million Degree Corona in the cool AGB Star, Y Gem

Type: GO Total Time (ks): 10

PI Name: Raghvendra Sahai

Abstract: We propose to make multi-epoch observations of the X-ray (and radio contiuum) emission from a cool AGB star, Y Gem. This star shows relatively strong X-ray emission implying the presence of 50 million degree coronal gas, and highly-variable FUV and NUV fluxes - likely evidence of variable accretion onto a magnetized accretion disk in a binary system. Y Gem is the most prominent member of a new class of AGB stars with FUV excesses identified using the GALEX archive. Our study will allow us to study the never-before explored phase of an active accretion disk in an AGB star with a binary companion. Such disks are believed to ultimately produce collimated jets that transform AGB circumsetllar envelopes into bipolar planetary nebulae.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+07:41:08.50	+20:25:44.30	Y Gem	ACIS-S	None	10.0

Subject Category: STARS AND WD

Proposal Number: 16200849

Title: The Secret Lives of Cepheids: Are Cepheids X-ray Variables?

Type: GO Total Time (ks): 40

PI Name: Edward Guinan

Abstract: We propose ACIS-I observations of the 9.84-day Cepheid beta Dor to confirm X-ray variability. The data will complement our Chandra/XMM data and HST FUV spectroscopy for this important star, whose FUV emission lines show phased 10,000 300,000 K plasma variability, peaking between pulsation phases 0.7 0.9 and originating from pulsation-induced shocks. We request two 45-ksec exposures of beta Dor to confirm the X-ray variability observed in our previous observations and help complete the X-ray light curve of this Cepheid. If confirmed, the phasing of the X-ray activity will contrast to that of the FUV emissions and provide crucial information on atmospheric heating mechanisms. We also propose a 40-ksec visit for the prototype Cepheid del Cep to confirm similar X-ray variability as beta Dor.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+22:29:10.30	+58:24:54.70	delta Cep	ACIS-I	None	40.0

Subject Category: STARS AND WD

Proposal Number: 16200863

Title: The Chandra-Kepler Flare Survey

Type: LP Total Time (ks): 500

PI Name: Jeremy Drake

Abstract: The Kepler K2 mission offers a unique chance to obtain the first simultaneous X-ray and white light (WL) observations of superflares on samples of nearby active, coeval stars. In large solar flares, X-ray emission represents only a few percent of the total energy dissipated, with WL and CME's dominating. For flaring active stars this implies up to 10% of Lbol is expended on flares! Chandra observations of rho Oph, the Pleiades and Praesepe simultaneous with K2 will observe superflares from 10^32-10^36 erg and test solar WL - X-ray relations for active stars. The results are central to flare energy release on stars through time, the impact of stellar flares and activity on protoplanetary disks and exoplanets, and the fundamental efficiency of magnetic dynamos in dissipating energy.

R.A.	Dec.	Target Name	Det.	Grating	Exp. Time (ks)
+16:27:17.20	-24:34:39.00	Rho Oph Cloud A	ACIS-I	None	100.0
+03:46:46.00	+24:04:06.00	Pleiades	ACIS-I	None	200.0
+08:39:50.00	+19:31:41.00	Praesepe	ACIS-I	None	200.0

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