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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"

45463 results found.

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

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