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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: Optical Afterglow
  2. XRF020903: TNG and Asiago photometry
  3. GRB 020903: Optical observations at RIKEN
  4. XRF 020903: Correction to GCN 1560
  5. XRF 020903: VRI observations
  6. IPN triangulation of GRB020926 (single large error box)
  7. GRB 020903: correction to GCN 1557
  8. XRF 020903: R band observations
  9. XRF 020903: Archival Optical Images
  10. Radio Observations of XRF 020903: The Missing Link
  11. XRF 020903: Supernova
  12. IPN triangulation of GRB020926 (two large error boxes)
  13. GRB020924 (ecliptic latitude-only localization)
  14. IPN triangulation of GRB020923 (two error boxes)
  15. IPN annulus for GRB020923
  16. IPN triangulation of GRB020914B
  17. Improved IPN position for GRB020918 (two large error boxes)
  18. IPN annulus for GRB020914B
  19. IPN triangulation of GRB020918 (annulus)
  20. IPN triangulation of GRB020911 (2 large error boxes)
  21. IPN triangulation of GRB020914 - clarification and additional information
  22. IPN triangulation of GRB020914
  23. GRB 020305: HST/STIS observations
  24. Confirmation of IPN error box for GRB020910
  25. IPN triangulation of GRB020910
  26. IPN GCN Circulars now to be issued without restriction
  27. Single IPN error box for GRB020904
  28. XRF 020903: optical observation at Kyoto
  29. GRB020322 : HST/STIS observations
  30. XRF 020903: Optical observations
  31. IPN triangulation of GRB020904
  32. XRF 020903: Optical observations
  33. IPN detection of a burst from SGR1900+14
  34. XRF 020903, optical observations
  35. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  36. INTEGRAL GRBs added to GCN
  37. GRB020813: optical observation
  38. GRB020812: optical observation
  39. GRB020819(=H2275): Revised Localization with HETE Soft X-ray
  40. SGR1900+14 burst localized by HETE
  41. GRB020813: High-resolution optical spectroscopy
  42. GRB020819: optical observations at Bisei
  43. GRB020812: negative optical observations
  44. GRB 020812: optical observation at Kyoto University
  45. Second epoch K band imaging of GRB 020819
  46. GRB020813, Baade 6.5m data now available
  47. GRB 020813 : HST observations
  48. Confirming no variability for GRB02081
  49. GRB020819 : Optical observations at KISO
  50. GRB 020812: early time optical observation at Ouda Station
  51. GRB020813: VRI Decay Slopes
  52. GRB020813: Magellan BVRI Photometry
  53. GRB 020819 : OT candidate - confirmation of non variability
  54. GRB 020819: Optical observations
  55. K band observation of GRB 020819
  56. GRB020819: optical observations
  57. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  58. IPN triangulation of GRB020819 (HETE 2275)
  59. HETE 2275: Optical observations
  60. GRB020813: optical and NIR observations
  61. GRB020813: Fading X-ray Afterglow Observed with Chandra
  62. GRB020813, UBVRI field calibration
  63. GRB 020813: addendum to GCN 1498
  64. GRB020813: optical observations at Bisei
  65. GRB020813: V-band decay slope
  66. GRB020812: NIR observations
  67. Polarimetry of GRB020813: evidence for variability
  68. GRB020813 IRAM millimeter observations
  69. GRB020812: optical observations
  70. GRB020813: High-Resolution Optical Observations
  71. GRB020813(=H2262): Revised Localization with HETE SXC
  72. GRB 020812: optical observation at Bisei
  73. GRB020813: Early Time Magnitude
  74. GRB020813: optical observations; possible host galaxy
  75. GRB 020813, radio detection
  76. GRB 020812 : optical afterglow candidate
  77. GRB020813, optical observations
  78. Millimeter observation of GRB 020813
  79. GRB020812: optical observations
  80. GRB 020813 : KISO multiband optical observations
  81. GRB020813, optical observations
  82. IPN error box for GRB020813
  83. IPN triangulation of GRB020813
  84. GRB020812: possible afterglow candidate
  85. Early Time Limits for GRB020813
  86. GRB020812: possible afterglow candidate
  87. GRB020813, astrometric position
  88. Spectropolarimetry of GRB 020813
  89. GRB 020813 Afterglow Observations; Possible break
  90. GRB 020813: Absorption redshift
  91. GRB 020813 multiband optical observations
  92. GRB020813: optical afterglow
  93. GRB020813: Fading of Candidate OT
  94. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  95. GRB020813: Candidate Optical Afterglow
  96. GRB 020812 optical observation
  97. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  98. GRB 020715, optical observations
  99. GRB 020714, optical observations
  100. GRB020801: Imaging of Suggested OT Counterpart at the Magellan

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