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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"

37956 results found.

  1. GRB021004, astrometric position
  2. GRB021004, Optical Observations
  3. IRAM Millimeter detection of GRB 021004
  4. GRB 021004: Optical observations at RIKEN
  5. GRB 021004 radio observation
  6. GRB 021004: Optical Observations
  7. GRB021004: continued fading
  8. GRB 021004: Optical Photometry at 1.5 Days
  9. GRB021004, Optical Observations
  10. GRB021004, BVRcIc field photometry
  11. GRB 021004: Optical observations
  12. GRB 021004: optical counterpart
  13. GRB 021004, optical observations
  14. GRB021004: Optical Spectroscopy
  15. GRB 021004: Optical Observations
  16. GRB 021004, SPM optical observations
  17. GRB 021004, optical observations
  18. GRB 021004 radio search
  19. GRB 021004: radio observations
  20. GRB 021004: steepening of the optical decay slope
  21. GRB021004: Upper limits from recent and historical observations
  22. XRF020903, BVRI field photometry
  23. GRB021004: optical observations at Nyrola
  24. GRB021004: Absorption redshift
  25. GRB 021004: Kyoto observation
  26. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  27. GRB021004: Optical Afterglow
  28. GRB 020903: Optical observations at RIKEN
  29. IPN triangulation of GRB020926 (single large error box)
  30. GRB 020903: correction to GCN 1557
  31. XRF 020903: R band observations
  32. Radio Observations of XRF 020903: The Missing Link
  33. IPN triangulation of GRB020926 (two large error boxes)
  34. GRB020924 (ecliptic latitude-only localization)
  35. IPN triangulation of GRB020923 (two error boxes)
  36. IPN annulus for GRB020923
  37. IPN triangulation of GRB020914B
  38. Improved IPN position for GRB020918 (two large error boxes)
  39. IPN annulus for GRB020914B
  40. IPN triangulation of GRB020918 (annulus)
  41. IPN triangulation of GRB020911 (2 large error boxes)
  42. IPN triangulation of GRB020914 - clarification and additional information
  43. IPN triangulation of GRB020914
  44. GRB 020305: HST/STIS observations
  45. Confirmation of IPN error box for GRB020910
  46. IPN triangulation of GRB020910
  47. IPN GCN Circulars now to be issued without restriction
  48. Single IPN error box for GRB020904
  49. XRF 020903: optical observation at Kyoto
  50. GRB020322 : HST/STIS observations
  51. IPN triangulation of GRB020904
  52. IPN detection of a burst from SGR1900+14
  53. INTEGRAL GRBs added to GCN
  54. GRB020813: High-resolution optical spectroscopy
  55. GRB 020812: optical observation at Kyoto University
  56. Second epoch K band imaging of GRB 020819
  57. GRB020813, Baade 6.5m data now available
  58. GRB 020813 : HST observations
  59. Confirming no variability for GRB02081
  60. GRB020819 : Optical observations at KISO
  61. GRB 020812: early time optical observation at Ouda Station
  62. GRB020813: VRI Decay Slopes
  63. GRB 020819 : OT candidate - confirmation of non variability
  64. GRB 020819: Optical observations
  65. K band observation of GRB 020819
  66. GRB020819: optical observations
  67. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  68. IPN triangulation of GRB020819 (HETE 2275)
  69. GRB020813, UBVRI field calibration
  70. GRB 020813: addendum to GCN 1498
  71. GRB020813: optical observations at Bisei
  72. GRB020813: V-band decay slope
  73. Polarimetry of GRB020813: evidence for variability
  74. GRB020813 IRAM millimeter observations
  75. GRB020812: optical observations
  76. GRB 020812: optical observation at Bisei
  77. GRB020813: optical observations; possible host galaxy
  78. GRB 020813, radio detection
  79. GRB 020812 : optical afterglow candidate
  80. Millimeter observation of GRB 020813
  81. GRB020812: optical observations
  82. GRB 020813 : KISO multiband optical observations
  83. IPN error box for GRB020813
  84. IPN triangulation of GRB020813
  85. GRB020812: possible afterglow candidate
  86. Early Time Limits for GRB020813
  87. GRB020812: possible afterglow candidate
  88. GRB020813, astrometric position
  89. Spectropolarimetry of GRB 020813
  90. GRB 020813 Afterglow Observations; Possible break
  91. GRB 020813: Absorption redshift
  92. GRB 020813 multiband optical observations
  93. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  94. GRB 020812 optical observation
  95. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  96. GRB 020715, optical observations
  97. GRB 020714, optical observations
  98. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  99. HST Imaging of the Host of GRB 011121
  100. GRB020801, optical afterglow candidate

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