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Kepler Light Curves Optimized For Asteroseismology (KEPSEISMIC)

HLSP Authors: Savita Mathur, Ângela Santos, Rafael A. García

García et al., 2011, MNRAS, 414, L6 | García et al., 2014, A&A, 568, 10 | Pires et al., 2015, A&A, 574, 18

Introduction

Description of Data Products

Data Access

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Introduction

KEPSEISMIC light curve for KIC 1572049 obtained with a 20-d filter and the respective power spectrum.
KEPSEISMIC light curve for KIC 1572049 obtained with a 55-d filter and the respective power spectrum.
KEPSEISMIC light curve for KIC 1572049 obtained with a 80-d filter and the respective power spectrum.

KEPSEISMIC light curves are obtained from Kepler pixel-data files using large custom apertures that produce more stable light curves on longer time scales for seismic studies. For each pixel in the pixel-data file, a reference weighted flux value is computed as the 99.9th percentile of the flux divided by its error representing a measure of the signal-to-noise ratio. Starting from the center of the point-spread function of the target star pixels, new pixels are added in one direction of the mask if two conditions are fulfilled: i) the reference weighted flux of the pixel is higher than a threshold of 100; ii) the weighted flux is smaller than the value of the previous pixel within a small tolerance. In most cases, this second condition allows the team to remove the pixels corresponding to a second star present in the aperture.

The resultant light curve is processed through the implementation of the Kepler Asteroseismic Data Analysis and Calibration Software (KADACS, García et al. 2011). KADACS corrects for outliers, jumps, and drifts, properly concatenates the independent Kepler Quarters in a star-by-star basis. It also fills the gaps shorter than 20 days in long cadence data following in-painting techniques based on a multi-scale cosine transform (García et al. 2014, Pires et al. 2015). The resulting light curves are high-pass filtered at 20, 55 days (quarter by quarter) and 80 days (using the full light curve at once) yielding three different light curves for each target. This ensures the homogeneity of the treatment done to the light curves when a single filter is used (e.g. for studies of the stellar convective background). For light curves longer than one month, KADACS corrects for discontinuities at the edges of the Kepler Quarters. You can refer to the full set of KEPSEISMIC observations using the DOI http://dx.doi.org/10.17909/t9-mrpw-gc07.

Description of Data Products

Each file name follows a syntax of "hlsp_kepseismic_kepler_phot_kplr{kicid}-{filter}_kepler_v1_{exten}", where:

  • {kicid} = 9-digit, zero-padded Kepler Input Catalog (KIC) ID.
  • {filter} = Width in days of the high-pass filter applied, e.g., "20d".
  • {exten} = File extension, one of:
    • {_cor-filt-inp.fits} = light curve corrected by the KADACS software with the gap filling using the inpainting technique.
    • {_cor-psd-filt-inp.fits} = power spectrum density of the light curve produced above.
    • {_preview.png} = preview of the corrected light curve as a function of time (top panel) and the corresponding power spectrum density as a function of frequency (bottom panel) as shown in the graph on this webpage.
The files are organized into subdirectories based on the following path structure: {....}/kepseismic/{mmmm}00000/{nnnnn}/{xx}d-filter/, where:
  • {mmmm} = The first four digits, zero-padded, of the KIC ID.
  • {nnnnn} = The last five digits, zero-padded, of the KIC ID.
  • {xx} = The width of the high-pass filter, one of "20", "55", or "80".

Data Access

In the future you will be able to retrieve the light curve and previews using the MAST Portal or through MAST Astroquery. In the mean time, you can directly download them via wget/cURL scripts by adding "https://archive.stsci.edu/hlsps/" to the front of the file paths and names described above, or by browsing the table below, sorted by Kepler IDs.

Targets Sorted By First Four Digits Of Their Kepler ID
0001xxxxx 0007xxxxx 0008xxxxx 0010xxxxx
0011xxxxx 0012xxxxx 0014xxxxx 0015xxxxx
0017xxxxx 0018xxxxx 0019xxxxx 0020xxxxx
0021xxxxx 0022xxxxx 0023xxxxx 0024xxxxx
0025xxxxx 0026xxxxx 0027xxxxx 0028xxxxx
0029xxxxx 0030xxxxx 0031xxxxx 0032xxxxx
0033xxxxx 0034xxxxx 0035xxxxx 0036xxxxx
0037xxxxx 0038xxxxx 0039xxxxx 0040xxxxx
0041xxxxx 0042xxxxx 0043xxxxx 0044xxxxx
0045xxxxx 0046xxxxx 0047xxxxx 0048xxxxx
0049xxxxx 0050xxxxx 0051xxxxx 0052xxxxx
0053xxxxx 0054xxxxx 0055xxxxx 0056xxxxx
0057xxxxx 0058xxxxx 0059xxxxx 0060xxxxx
0061xxxxx 0062xxxxx 0063xxxxx 0064xxxxx
0065xxxxx 0066xxxxx 0067xxxxx 0068xxxxx
0069xxxxx 0070xxxxx 0071xxxxx 0072xxxxx
0073xxxxx 0074xxxxx 0075xxxxx 0076xxxxx
0077xxxxx 0078xxxxx 0079xxxxx 0080xxxxx
0081xxxxx 0082xxxxx 0083xxxxx 0084xxxxx
0085xxxxx 0086xxxxx 0087xxxxx 0088xxxxx
0089xxxxx 0090xxxxx 0091xxxxx 0092xxxxx
0093xxxxx 0094xxxxx 0095xxxxx 0096xxxxx
0097xxxxx 0098xxxxx 0099xxxxx 0100xxxxx
0101xxxxx 0102xxxxx 0103xxxxx 0104xxxxx
0105xxxxx 0106xxxxx 0107xxxxx 0108xxxxx
0109xxxxx 0110xxxxx 0111xxxxx 0112xxxxx
0113xxxxx 0114xxxxx 0115xxxxx 0116xxxxx
0117xxxxx 0118xxxxx 0119xxxxx 0120xxxxx
0121xxxxx 0122xxxxx 0123xxxxx 0124xxxxx
0125xxxxx 0126xxxxx 0127xxxxx 0128xxxxx
0129xxxxx