... 4U 1954+319

Partly based on observations collected at the Astronomical Observatory of Bologna in Loiano, Italy.

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... curve

Available at http://xte.mit.edu/ASM_lc.html

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... CIAO

Available at http://cxc.harvard.edu/ciao/

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... CALDB

Available at http://cxc.harvard.edu/caldb/

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... angles

See the Chandra Proposers' Observatory Guide: http://cxc.harvard.edu/proposer/POG/html/

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... XMM-SAS

Available at http://xmm.vilspa.esa.es/sas/

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... IRAF

IRAF is the Image Reduction and Analysis Facility made available to the astronomical community by the National Optical Astronomy Observatories, which are operated by AURA, Inc., under contract with the U.S. National Science Foundation. It is available at http://iraf.noao.edu/

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... DSS-II-Red

Available at http://archive.eso.org/dss/dss

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... USNO-A2.0

The USNO-A2.0 catalogue is available at http://archive.eso.org/skycat/servers/usnoa

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... Bruzual-Persson-Gunn-Stryker

Available at: ftp://ftp.stsci.edu/cdbs/cdbs1/grid/bpgs/

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... Jacoby-Hunter-Christian

Available at: ftp://ftp.stsci.edu/cdbs/cdbs1/grid/jacobi/

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