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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"

36152 results found.

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

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