XRT
(SAO, NASA, JAXA, NAOJ)

Hinode (was Solar-B) was launched at 6:36 a.m. on September 23, 2006 (Japan Standard Time).


2014-April-10
New XPOW: X-Flare & EUV Wave on March 29th, 2014

2014-April-01
New XPOW: Coronal Rain Extinguishes Active Region

2014-March-24
New XPOW: Lovely Eruption & M-Flare from November, 2011

2014-March-12
Important Calibration Software Update
Significant improvements have been made to the XRT_PREP code, which includes several new features in addition to minor bug fixes. Users should ensure that their SSW IDL libraries are up-to-date.

The UNCERT_MAP keyword has been added to provide an array of photometric errors due to calibration uncertainties (e.g., uncertainty in the dark subtraction, Fourier filtering, vignetting correction, exposure time, etc.). For details, see Kobelski et al. 2014, Solar Physics, in press; arXiv:1312.4850. The error array provides a basal estimate of uncertainty in the XRT data. Note that photon noise errors are not included, as these depend on the detailed thermal structure of the target, since XRT is a broadband detector.

The DESPIKE_DESPOT keyword has also been introduced to provide a cosmetic correction for contamination spots and dust on the CCD (using the XRT_SPOTCOR subroutine), in addition to particle hits. The spot correction uses thin plate splines (in most cases) to smoothly interpolate between boundary pixels outside of the given spot/dust area. It is highly recommended that the user employ this in conjunction with the GRADE_MAP keyword, which generates a pixel grade map so that the location of spots and dust can be identified. Note that this correction is purely cosmetic; pixels affected by dust and/or spots should not be used for quantitative analysis. A new despiking code (XRT_DESPIKE2), which better avoids over-correcting the data, has also been introduced.

The dust on the CCD has been growing between CCD bakeouts and shrinking after bakeouts since May of 2012, suggesting that contamination is starting to adhere to the dust temporarily. The cosmetic correction code also adjusts (approximately) for the time-dependent dust size. A new catagory of pixel grade, dust growth pixels, has been added to the output of XRT_PIXEL_GRADE.

Usage notes can be found in the XRT_PREP program header (and the headers of related routines). Detailed information is also provided in an updated version of the XRT Analysis Guide.

2014-March-11
New XPOW: Filament Eruption with Unusual Twisting Motions

2014-February-14
New XPOW: 112 Hours of Full-Sun X-Ray Images

2014-February-10
New XPOW: Mysterious Flare-Ribbon-Like Structure

2014-January-30
XPOW Archive Upgrade
The XPOW Archive has been upraded to be more easily searched. Each XPOW entry now also includes "keywords" that can be used to find related posts by querying the archive.

2014-January-24
New XPOW: Sigmoids on Parade!

2014-January-17
New XPOW: Polar Aurora

2014-January-03
New XPOW: Cutest. Loop. Ever.

2013-December-26
New XPOW: X-Ray Sun Two-Month Mashup

2013-December-06
New XPOW: Full-Sun Images in Three Temperature Ranges

2013-November-25
New XPOW: X1.1 Flare with CME on November 10th, 2013

2013-November-20
New XPOW: Heart-shaped productive Active Region 11875

2013-November-18
New Observation Resources!
The XRT Team has released two new resources for browsing XRT data. First, we have a revamped synoptic gallery. All of XRT's twice-daily full sun images are on display, and starting in June of 2013, each image is a composite of 3 exposures (long-medium-short) instead of 2. This provides a more lovely showing of the broad dynamic range the sun is currently displaying in its maximum activity phase.

Next, we've got the XRT Flare Catalog. The catalog includes basic information for all the flares that have occurred during the Hinode mission, along with summaries and preview movies of XRT's observations for each event. Links to both resources can be found under the "Data" tab in the sidebar and under "Observations" on the Mission Ops page.

2013-November-12
New XPOW: Solar Eclipse of November 3rd, 2013

2013-November-5
Calibration Update: The calibration of the instrument response functions has been updated, and the XRT response software in SolarSoft has also been updated accordingly (e.g. make_xrt_wave_resp.pro, xrt_teem.pro, xrt_eff_area.pro, etc.). The change adjusts some of the filter thicknesses to reflect the analysis of Narukage et al. 2013. As a result, the estimated effective areas of those filters (med-Be, med-Al, thick-Be, & thick-Al) have changed.

Click here for a plot of the updated temperature response functions (dotted lines indicated the previous calibration).

The new calibration files have been made available in SolarSoft. Please ensure that your SSW IDL libraries are up to date. See program headers and/or the XRT Analysis Guide for documention, and please direct questions and bug reports to xrt_manager [at] head [dot] cfa [dot] harvard [dot] edu.

2013-October-31
New XPOW: More Flares from AR 11882!

2013-October-29
New XPOW: M-Flares with CMEs on October 26th & 27th

2013-October-15
New XPOW: Sigmoid Eruptions on August 7th, 2013

2013-October-07
New XPOW: B Flare on September 23rd

2013-September-25
Thesis Updates!
Congratulations from the XRT Team to Lucas Tarr and Will Hanneman for recently completing their respective theses. The newly minted Dr. Tarr successfully defended his PhD dissertation on "Energetic Consequences of Flux Emergence", and Mr. Hanneman completed a master's thesis on the "Thermal Structure of Current Sheets and Supra-Arcade Downflows".

2013-September-23
XRT Spotlight: Head over to the Bad Astronomy blog at Slate for an article by Phil Plait on XRT eclipse observations from last May.

See the XRT News page for older XRT news items.


The Hinode X-Ray Telescope (XRT) is a high-resolution grazing-incidence telescope, which is a successor to the highly successful Yohkoh Soft X-Ray Telescope (SXT). A primary purpose of the Hinode XRT is to observe the generation, transport, and emergence of solar magnetic fields, as well as the ultimate dissipation of magnetic energy in forms such as flares and pico-flares, coronal heating, and coronal mass ejections. The XRT aboard Hinode observes the dissipation part of the life-cycle story of solar magnetic fields. High-resolution soft X-ray images reveal magnetic field configuration and its evolution, allowing us to observe the energy buildup, storage and release process in the corona for any transient event. One of the unique features of XRT is its wide temperature coverage to see all the coronal features that are not seen with any normal incidence telescope.

The XRT consists of the X-ray and visible light optics, focal plane mechanisms (filters and shutter), and the 2k x 2k CCD camera. The Mission Data Processor (MDP) also plays a vital role for XRT.

The XRT was designed and developed by the Japan-US collaboration between Smithsonian Astrophysical Observatory (SAO), NASA MSFC, JAXA, and NAOJ. The XRT telescope was tested and calibrated at the XRCF at MSFC, and the CCD camera was tested and calibrated in X-rays at the ATC of the NAOJ with JAXA.

If XRT data is used in a published article or report, please give a proper Acknowledgement:

"Hinode is a Japanese mission developed and launched by ISAS/JAXA, with NAOJ as domestic partner and NASA and STFC (UK) as international partners. It is operated by these agencies in co-operation with ESA and the NSC (Norway)."

If an XRT image is displayed in a popular article, on a website, et cetera, then please acknowledge the contributing institutions:

"(SAO, NASA, JAXA, NAOJ)"

You may find a list of the XRT instrument papers and other important references that should be considered for inclusion in your XRT science paper HERE.

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