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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"

3400 results found.

  1. GRB 041006 : optical follow-up observation at Lulin Observatory
  2. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  3. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  4. GRB040924: Optical afterglow properties
  5. TAROT Observations of GRB 040916 (HETE #3558)
  6. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  7. GRB040912 : Kiso Optical follow-up observation
  8. GRB 040812: Second epoch CXO Observations
  9. CXO observation of GRB 040812
  10. GRB040706:observation at University of Miyazaki
  11. IPN Summary of SGR1806-20 Activity in 2004
  12. Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
  13. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  14. Lulin optical follow-up observations of GRB031026
  15. XRF 030824: additional observations at CFHT
  16. IPN triangulation of GRB031007 (two large error boxes)
  17. IPN triangulation of GRB030922B (large error box)
  18. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  19. IPN triangulation of GRB030919 (large error box)
  20. GRB030913: AAVSO optical observations
  21. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  22. IPN triangulation of GRB030714 (two large error boxes)
  23. IPN triangulation of GRB030626 (two large error boxes)
  24. GRB030429, refiend optical brightness
  25. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  26. GRB030429: Optical Observations
  27. GRB 030329, the review of the sky area in plate archive (1950-1998)
  28. GRB030329: optical observations at Tokyo Tech
  29. GRB030329 - near contemporaneous optical limits from CONCAM
  30. IPN triangulation of GRB030325 (single small error box)
  31. IPN triangulation of GRB030325 (two small error boxes)
  32. IPN triangulation of GRB030320 (small error box)
  33. GRB 030227: Optical limit at RIKEN
  34. GRB 030228, optical observations
  35. GRB 030227: fading of candidate optical afterglow 'S1-A'
  36. GRB 030227, possible optical counterpart of XMM-Newton source
  37. GRB030227 - faint tentative OT candidate
  38. GRB 030227: Kyoto optical observation
  39. IPN triangulation of GRB030119 (two large error boxes)
  40. IPN triangulation of GRB030117 (two large error boxes)
  41. IPN triangulation of GRB021219 - CORRECTION
  42. GRB021219: a long GRB localized by INTEGRAL
  43. IPN triangulation of GRB021206 (small error box)
  44. GRB021104: Optical Observations
  45. IPN triangulation of GRB021020 (smaller error box)
  46. GRB021016(=H2397): A Long GRB Localized by HETE
  47. IPN triangulation of GRB021008 (two small error boxes)
  48. GRB 021004: Optical measurement at OHP
  49. GRB 021004: Optical Photometry at 2.5 Days
  50. GRB021004: Update Bisei photometric data
  51. IPN triangulation of GRB020914
  52. Confirmation of IPN error box for GRB020910
  53. IPN triangulation of GRB020910
  54. Single IPN error box for GRB020904
  55. IPN triangulation of GRB020904
  56. GRB 020812: optical observation at Kyoto University
  57. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  58. GRB020812: optical observations
  59. IPN triangulation of GRB020708
  60. IPN triangulation of GRB020708
  61. GRB 020705: Optical observations
  62. GRB 020603, R-band observation
  63. GRB020531: optical observations
  64. GRB 020409: Optical Observations
  65. GRB020124 optical observations with RIBOTS/RIMOTS
  66. GRB 020321: Candidate X-ray Counterparts
  67. GRB011212: Optical Observations
  68. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  69. GRB011212: Optical observations at Gunma
  70. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  71. IPN triangulation of GRB011121
  72. GRB 010629 Optical Observations
  73. GRB 010222
  74. IPN/RXTE TRIANGULATION OF GRB010126
  75. GRB010126, TNG R-band observations
  76. GRB010126 optical observations
  77. IPN TRIANGULATION OF GRB010126
  78. IPN triangulation of GRB001219
  79. IPN triangulation of GRB000911
  80. IPN localization of GRB000820
  81. IPN localization of GRB000811
  82. GRB000607, A SHORT, HARD BURST
  83. GRB000424, optical observations
  84. IPN localization of GRB991226
  85. GRB 991106, LOTIS Optical Observations
  86. IPN/NFI error box for GRB991014
  87. IPN error box for GRB990915 (=BATSE 7766)
  88. GRB990806 UBVRIJHK observations
  89. GRB990704, optical observations
  90. IPN error box for GRB990527
  91. IPN localization for GRB990506
  92. GRB 990316, Optical observations
  93. GRB990308, Possible new SGR~0209+70
  94. GRB990123, early optical counterpart detection
  95. GRB 981226 Optical Observations
  96. GRB 981226 optical observations
  97. GRB980326 IPN annulus
  98. Near-IR follow-up on GRB 971227
  99. Optical Observations of the GRB 971227 field
  100. GRB971227: Further CAHA R-band images

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