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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"

45461 results found.

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

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