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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

18353 results found.

  1. GRB040106: refined X-ray transient position
  2. GRB 031220: Optical observations of Chandra X-ray sources
  3. XMM-Newton Images of GRB 040106
  4. GRB031220: observation at Univercity of Miyazaki
  5. XMM-Newton observation of GRB040106
  6. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  7. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  8. GRB 031220 : Kyoto Optical Observation
  9. GRB 031220: Subaru observation
  10. GRB 031220: Optical observation at Tokyo Tech
  11. GRB 2974 follow-up observations
  12. GRB031203, improved XMM position
  13. XMM-Newton Observations of GRB031203: Preliminary Images
  14. IPN/HETE localization of GRB031203B (=H2949; large error box)
  15. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  16. XMM-Newton Observation of GRB031203
  17. XMM-Newton Observation of GRB031203
  18. GRB 031203: IR NTTobservations do not confirm REM detection
  19. GRB 031203: Apparent Spectral Break
  20. GRB031203: Planned XMM-Newton observation II
  21. GRB 031203: IR REM Observations
  22. GRB031203: Optical Observations
  23. GRB 031203 XMM-Newton observation
  24. GRB031203: Planned XMM-Newton observation
  25. GRB 030329: Planned XMM-Newton Observation
  26. GRB 031111B (= H2925) : Kyoto Optical Observation
  27. GRB 031111, optical observations
  28. XRF031109 (=H2919): A very long XRF localized by HETE
  29. IPN triangulation of GRB031108 (large error box)
  30. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  31. GRB030929/SN2003jd association unlikely based on IPN localiztion
  32. IPN triangulation of GRB031027 (small error box)
  33. Lulin optical follow-up observations of GRB031026
  34. IPN triangulation of GRB031024 (single error box)
  35. XRF 030824: additional observations at CFHT
  36. XRF 030723: Subaru Optical Observations
  37. XRF 030824: Early follow-up observation at Kiso observatory
  38. XRF 030723: Detection of the likely host galaxy
  39. IPN triangulation of GRB030919 (large error box)
  40. GRB030913: Subaru Optical Observations
  41. GRB 030913, optical candidate
  42. GRB 030913, BOOTES observations
  43. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  44. XRF030824: Optical observations
  45. IPN triangulation of GRB030903 (large error box)
  46. IBAS detection of bursts from SGR 1806-20
  47. Radio Observations of SGR1806-20
  48. GRB030823: optical observation at Tokyo Tech
  49. Lulin follow-up observations of GRB030823
  50. GRB 030817 = H2808 TAROT optical observations
  51. SGR 1808-20 (=H2802): A Possible new SGR
  52. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  53. XRF030723, BVRcIc field photometry update
  54. IPN triangulation of GRB030801 (large error box)
  55. GRB021206 optical counterpart upper limit
  56. IPN triangulation of GRB030726 (large error box)
  57. XRF030723 Radio Observations
  58. XRF 030723: confirmation of fading optical counterpart
  59. XRF030723(=H2777): Chandra Observations
  60. GRB030723: Upper limits from historical observations
  61. XRF030723: Palomar observations and proposed counterpart
  62. XRF030723, BVRcIc field photometry correction
  63. XRF030723, ROTSE-III Early Observations
  64. XRF030723, BVRcIc field photometry
  65. XRF 030723, optical observations
  66. XRF030723, optical observations
  67. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  68. SGR 1806-20, submm observations
  69. RXTE PCA Observations of SGR1806-20 Region
  70. GRB030329: Subaru Optical Spectroscopy
  71. GRB030329, optical observation in May
  72. IPN triangulation of GRB030626 (single large error box)
  73. IPN triangulation of GRB030626 (two large error boxes)
  74. HETE detection of burst from SGR1806-20
  75. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  76. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  77. GRB 030528: tentative NIR counterpart
  78. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  79. GRB030528, BVRI field photometry
  80. GRB030329, SPM optical observations
  81. GRB030528(=H2724): Revised SXC Localization
  82. GRB 030528 Bisei optical observation
  83. GRB 030528 (=H2724) Kyoto optical observation
  84. GRB 030329 Optical Observations
  85. GRB 021004: HST observations
  86. GRB030324: Further Observations of the Candidate Optical Afterglow
  87. HETE GRB030329, correction to Rc Observations in Loiano
  88. GRB 030329: Optical limit (contemporaneous imaging)
  89. IPN triangulation of GRB030509 (single error box)
  90. GRB030429, refiend optical brightness
  91. GRB030418, BVRcIc field photometry
  92. GRB030429, BVRcIc field photometry
  93. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  94. GRB030329: RTT150 optical observations and upper limit for a host
  95. GRB030329: RTT150 optical observations and upper limit for a host
  96. GRB 030429: redshift from VLT spectroscopy
  97. GRB030501: TAROT candidate afterglow present in archival images
  98. GRB 030429: confirmation of afterglow candidate
  99. GRB 030329 Oprical observations in Rozhen observatory
  100. GRB030329, SPM optical observations

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