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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"

36048 results found.

  1. GRB 021004: Optical Observations
  2. GRB 021004, SPM optical observations
  3. GRB 021004, optical observations
  4. GRB 021004 radio search
  5. GRB 021004: radio observations
  6. GRB 021004: steepening of the optical decay slope
  7. GRB021004: Upper limits from recent and historical observations
  8. XRF020903, BVRI field photometry
  9. GRB021004: optical observations at Nyrola
  10. GRB021004: Absorption redshift
  11. GRB 021004: Kyoto observation
  12. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  13. GRB021004: Optical Afterglow
  14. GRB 020903: Optical observations at RIKEN
  15. IPN triangulation of GRB020926 (single large error box)
  16. GRB 020903: correction to GCN 1557
  17. XRF 020903: R band observations
  18. Radio Observations of XRF 020903: The Missing Link
  19. IPN triangulation of GRB020926 (two large error boxes)
  20. GRB020924 (ecliptic latitude-only localization)
  21. IPN triangulation of GRB020923 (two error boxes)
  22. IPN annulus for GRB020923
  23. IPN triangulation of GRB020914B
  24. Improved IPN position for GRB020918 (two large error boxes)
  25. IPN annulus for GRB020914B
  26. IPN triangulation of GRB020918 (annulus)
  27. IPN triangulation of GRB020911 (2 large error boxes)
  28. IPN triangulation of GRB020914 - clarification and additional information
  29. IPN triangulation of GRB020914
  30. GRB 020305: HST/STIS observations
  31. Confirmation of IPN error box for GRB020910
  32. IPN triangulation of GRB020910
  33. IPN GCN Circulars now to be issued without restriction
  34. Single IPN error box for GRB020904
  35. XRF 020903: optical observation at Kyoto
  36. GRB020322 : HST/STIS observations
  37. IPN triangulation of GRB020904
  38. IPN detection of a burst from SGR1900+14
  39. INTEGRAL GRBs added to GCN
  40. GRB020813: High-resolution optical spectroscopy
  41. GRB 020812: optical observation at Kyoto University
  42. Second epoch K band imaging of GRB 020819
  43. GRB020813, Baade 6.5m data now available
  44. GRB 020813 : HST observations
  45. Confirming no variability for GRB02081
  46. GRB020819 : Optical observations at KISO
  47. GRB 020812: early time optical observation at Ouda Station
  48. GRB020813: VRI Decay Slopes
  49. GRB 020819 : OT candidate - confirmation of non variability
  50. GRB 020819: Optical observations
  51. K band observation of GRB 020819
  52. GRB020819: optical observations
  53. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  54. IPN triangulation of GRB020819 (HETE 2275)
  55. GRB020813, UBVRI field calibration
  56. GRB 020813: addendum to GCN 1498
  57. GRB020813: optical observations at Bisei
  58. GRB020813: V-band decay slope
  59. Polarimetry of GRB020813: evidence for variability
  60. GRB020813 IRAM millimeter observations
  61. GRB020812: optical observations
  62. GRB 020812: optical observation at Bisei
  63. GRB020813: optical observations; possible host galaxy
  64. GRB 020813, radio detection
  65. GRB 020812 : optical afterglow candidate
  66. Millimeter observation of GRB 020813
  67. GRB020812: optical observations
  68. GRB 020813 : KISO multiband optical observations
  69. IPN error box for GRB020813
  70. IPN triangulation of GRB020813
  71. GRB020812: possible afterglow candidate
  72. Early Time Limits for GRB020813
  73. GRB020812: possible afterglow candidate
  74. GRB020813, astrometric position
  75. Spectropolarimetry of GRB 020813
  76. GRB 020813 Afterglow Observations; Possible break
  77. GRB 020813: Absorption redshift
  78. GRB 020813 multiband optical observations
  79. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  80. GRB 020812 optical observation
  81. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  82. GRB 020715, optical observations
  83. GRB 020714, optical observations
  84. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  85. HST Imaging of the Host of GRB 011121
  86. GRB020801, optical afterglow candidate
  87. Further refinement to IPN error box for GRB020531
  88. GRB020331: Late-time Optical Light Curve (re-submission)
  89. GRB020331: Late-time Optical Light Curve
  90. GRB 020405: HST observations reveal red bump
  91. IPN triangulation of GRB020714
  92. IPN triangulation of GRB020715 (=GRB150702)
  93. IPN triangulation of GRB020714
  94. IPN triangulation of GRB150702
  95. GRB 020410: Discovery of Probable OT by HST
  96. GRB 020124, HST observations of the fading afterglow
  97. IPN triangulation of GRB020708
  98. IPN triangulation of GRB020708
  99. IPN error box for GRB020706
  100. IPN triangulation of GRB020706

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