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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').
Advanced Search

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.

Advanced Search Examples (click to copy):

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

3040 results found.

  1. GRB 050813: Swift XRT afterglow localization
  2. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  3. GRB 050802: early Swift XRT analysis results
  4. GRB 050730, corrected photometry and break?
  5. GRB050801: Swift-BAT detection of a burst
  6. GRB 050730, spectra and optical photometry
  7. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  8. GRB 050603: Afterglow Identification from LCO
  9. Swift/BAT Detection of GRB050603
  10. GRB050528, XRT observations
  11. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  12. GRB 050505: early time observations
  13. GRB 050502 - A long GRB detected with INTEGRAL
  14. GRB 050416,optical observation
  15. GRB050412: P60 Observations
  16. GRB 050408: Optical limit
  17. GRB 050410, optical observations
  18. GRB 050408, optical observations
  19. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  20. GRB050331: No Afterglow Detected
  21. GRB 050331: Swift XRT Position
  22. GRB050223: analysis of the XMM-Newton observation
  23. GRB 050219b: candidate NIR afterglow
  24. GRB050223 XMM-Newton observation
  25. GRB 050223: Swift XRT Position
  26. GRB050219b: CORRECTION to time of UVOT observations
  27. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  28. GRB 050219b: CORRECTION to refined XRT position
  29. GRB 050219b: Optical and near-IR observations from LCO
  30. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  31. GRB 050219b: Refined XRT position
  32. GRB 050219b: CORRECTION: Swift XRT Position
  33. GRB 050219b: Swift XRT Position
  34. GRB 050209 Optical observations
  35. GRB 050209: Optical observation
  36. GRB 050123: KAIT observations
  37. Third epoch observations of SGR 1806-20 with VLA
  38. GRB041224: Swift-BAT detection of a soft burst
  39. GRB041219: Optical Afterglow Detection
  40. GRB 041006: GETS Optical Afterglow Observation
  41. GRB 041006 : optical follow-up observation at Lulin Observatory
  42. Bursts from SGR 1806-20: Preliminary INTEGRAL results
  43. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  44. GRB040924: Optical afterglow properties
  45. TAROT Observations of GRB 040916 (HETE #3558)
  46. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  47. GRB040912 : Kiso Optical follow-up observation
  48. GRB 040812: Second epoch CXO Observations
  49. CXO observation of GRB 040812
  50. GRB040706:observation at University of Miyazaki
  51. IPN Summary of SGR1806-20 Activity in 2004
  52. Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
  53. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  54. Lulin optical follow-up observations of GRB031026
  55. XRF 030824: additional observations at CFHT
  56. IPN triangulation of GRB031007 (two large error boxes)
  57. IPN triangulation of GRB030922B (large error box)
  58. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  59. IPN triangulation of GRB030919 (large error box)
  60. GRB030913: AAVSO optical observations
  61. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  62. IPN triangulation of GRB030714 (two large error boxes)
  63. IPN triangulation of GRB030626 (two large error boxes)
  64. GRB030429, refiend optical brightness
  65. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  66. GRB030429: Optical Observations
  67. GRB 030329, the review of the sky area in plate archive (1950-1998)
  68. GRB030329: optical observations at Tokyo Tech
  69. GRB030329 - near contemporaneous optical limits from CONCAM
  70. IPN triangulation of GRB030325 (single small error box)
  71. IPN triangulation of GRB030325 (two small error boxes)
  72. IPN triangulation of GRB030320 (small error box)
  73. GRB 030227: Optical limit at RIKEN
  74. GRB 030228, optical observations
  75. GRB 030227: fading of candidate optical afterglow 'S1-A'
  76. GRB 030227, possible optical counterpart of XMM-Newton source
  77. GRB030227 - faint tentative OT candidate
  78. GRB 030227: Kyoto optical observation
  79. IPN triangulation of GRB030119 (two large error boxes)
  80. IPN triangulation of GRB030117 (two large error boxes)
  81. IPN triangulation of GRB021219 - CORRECTION
  82. GRB021219: a long GRB localized by INTEGRAL
  83. IPN triangulation of GRB021206 (small error box)
  84. GRB021104: Optical Observations
  85. IPN triangulation of GRB021020 (smaller error box)
  86. GRB021016(=H2397): A Long GRB Localized by HETE
  87. IPN triangulation of GRB021008 (two small error boxes)
  88. GRB 021004: Optical measurement at OHP
  89. GRB 021004: Optical Photometry at 2.5 Days
  90. GRB021004: Update Bisei photometric data
  91. IPN triangulation of GRB020914
  92. Confirmation of IPN error box for GRB020910
  93. IPN triangulation of GRB020910
  94. Single IPN error box for GRB020904
  95. IPN triangulation of GRB020904
  96. GRB 020812: optical observation at Kyoto University
  97. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  98. GRB020812: optical observations
  99. IPN triangulation of GRB020708
  100. IPN triangulation of GRB020708

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