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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"
  1. GRB021004: Upper limits from recent and historical observations
  2. XRF020903, BVRI field photometry
  3. GRB021004: optical observations at Nyrola
  4. GRB021004: Absorption redshift
  5. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  6. GRB021004: optical observations at Bisei
  7. GRB 021004: Kyoto observation
  8. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  9. GRB021004: Optical Afterglow
  10. XRF020903: TNG and Asiago photometry
  11. GRB 020903: Optical observations at RIKEN
  12. XRF 020903: Correction to GCN 1560
  13. XRF 020903: VRI observations
  14. IPN triangulation of GRB020926 (single large error box)
  15. GRB 020903: correction to GCN 1557
  16. XRF 020903: R band observations
  17. XRF 020903: Archival Optical Images
  18. Radio Observations of XRF 020903: The Missing Link
  19. XRF 020903: Supernova
  20. IPN triangulation of GRB020926 (two large error boxes)
  21. GRB020924 (ecliptic latitude-only localization)
  22. IPN triangulation of GRB020923 (two error boxes)
  23. IPN annulus for GRB020923
  24. IPN triangulation of GRB020914B
  25. Improved IPN position for GRB020918 (two large error boxes)
  26. IPN annulus for GRB020914B
  27. IPN triangulation of GRB020918 (annulus)
  28. IPN triangulation of GRB020911 (2 large error boxes)
  29. IPN triangulation of GRB020914 - clarification and additional information
  30. IPN triangulation of GRB020914
  31. GRB 020305: HST/STIS observations
  32. Confirmation of IPN error box for GRB020910
  33. IPN triangulation of GRB020910
  34. IPN GCN Circulars now to be issued without restriction
  35. Single IPN error box for GRB020904
  36. XRF 020903: optical observation at Kyoto
  37. GRB020322 : HST/STIS observations
  38. XRF 020903: Optical observations
  39. IPN triangulation of GRB020904
  40. XRF 020903: Optical observations
  41. IPN detection of a burst from SGR1900+14
  42. XRF 020903, optical observations
  43. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  44. INTEGRAL GRBs added to GCN
  45. GRB020813: optical observation
  46. GRB020812: optical observation
  47. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  48. SGR1900+14 burst localized by HETE
  49. GRB020813: High-resolution optical spectroscopy
  50. GRB020819: optical observations at Bisei
  51. GRB020812: negative optical observations
  52. GRB 020812: optical observation at Kyoto University
  53. Second epoch K band imaging of GRB 020819
  54. GRB020813, Baade 6.5m data now available
  55. GRB 020813 : HST observations
  56. Confirming no variability for GRB02081
  57. GRB020819 : Optical observations at KISO
  58. GRB 020812: early time optical observation at Ouda Station
  59. GRB020813: VRI Decay Slopes
  60. GRB020813: Magellan BVRI Photometry
  61. GRB 020819 : OT candidate - confirmation of non variability
  62. GRB 020819: Optical observations
  63. K band observation of GRB 020819
  64. GRB020819: optical observations
  65. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  66. IPN triangulation of GRB020819 (HETE 2275)
  67. HETE 2275: Optical observations
  68. GRB020813: optical and NIR observations
  69. GRB020813: Fading X-ray Afterglow Observed with Chandra
  70. GRB020813, UBVRI field calibration
  71. GRB 020813: addendum to GCN 1498
  72. GRB020813: optical observations at Bisei
  73. GRB020813: V-band decay slope
  74. GRB020812: NIR observations
  75. Polarimetry of GRB020813: evidence for variability
  76. GRB020813 IRAM millimeter observations
  77. GRB020812: optical observations
  78. GRB020813: High-Resolution Optical Observations
  79. GRB020813(=H2262): Revised Localization with HETE SXC
  80. GRB 020812: optical observation at Bisei
  81. GRB020813: Early Time Magnitude
  82. GRB020813: optical observations; possible host galaxy
  83. GRB 020813, radio detection
  84. GRB 020812 : optical afterglow candidate
  85. GRB020813, optical observations
  86. Millimeter observation of GRB 020813
  87. GRB020812: optical observations
  88. GRB 020813 : KISO multiband optical observations
  89. GRB020813, optical observations
  90. IPN error box for GRB020813
  91. IPN triangulation of GRB020813
  92. GRB020812: possible afterglow candidate
  93. Early Time Limits for GRB020813
  94. GRB020812: possible afterglow candidate
  95. GRB020813, astrometric position
  96. Spectropolarimetry of GRB 020813
  97. GRB 020813 Afterglow Observations; Possible break
  98. GRB 020813: Absorption redshift
  99. GRB 020813 multiband optical observations
  100. GRB020813: optical afterglow

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