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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"

36158 results found.

  1. IRAM Millimeter detection of GRB 021004
  2. GRB 021004: Optical observations at RIKEN
  3. GRB 021004 radio observation
  4. GRB 021004: Optical Observations
  5. GRB021004: continued fading
  6. GRB 021004: Optical Photometry at 1.5 Days
  7. GRB021004, Optical Observations
  8. GRB021004, BVRcIc field photometry
  9. GRB 021004: Optical observations
  10. GRB 021004: optical counterpart
  11. GRB 021004, optical observations
  12. GRB021004: Optical Spectroscopy
  13. GRB 021004: Optical Observations
  14. GRB 021004, SPM optical observations
  15. GRB 021004, optical observations
  16. GRB 021004 radio search
  17. GRB 021004: radio observations
  18. GRB 021004: steepening of the optical decay slope
  19. GRB021004: Upper limits from recent and historical observations
  20. XRF020903, BVRI field photometry
  21. GRB021004: optical observations at Nyrola
  22. GRB021004: Absorption redshift
  23. GRB 021004: Kyoto observation
  24. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  25. GRB021004: Optical Afterglow
  26. GRB 020903: Optical observations at RIKEN
  27. IPN triangulation of GRB020926 (single large error box)
  28. GRB 020903: correction to GCN 1557
  29. XRF 020903: R band observations
  30. Radio Observations of XRF 020903: The Missing Link
  31. IPN triangulation of GRB020926 (two large error boxes)
  32. GRB020924 (ecliptic latitude-only localization)
  33. IPN triangulation of GRB020923 (two error boxes)
  34. IPN annulus for GRB020923
  35. IPN triangulation of GRB020914B
  36. Improved IPN position for GRB020918 (two large error boxes)
  37. IPN annulus for GRB020914B
  38. IPN triangulation of GRB020918 (annulus)
  39. IPN triangulation of GRB020911 (2 large error boxes)
  40. IPN triangulation of GRB020914 - clarification and additional information
  41. IPN triangulation of GRB020914
  42. GRB 020305: HST/STIS observations
  43. Confirmation of IPN error box for GRB020910
  44. IPN triangulation of GRB020910
  45. IPN GCN Circulars now to be issued without restriction
  46. Single IPN error box for GRB020904
  47. XRF 020903: optical observation at Kyoto
  48. GRB020322 : HST/STIS observations
  49. IPN triangulation of GRB020904
  50. IPN detection of a burst from SGR1900+14
  51. INTEGRAL GRBs added to GCN
  52. GRB020813: High-resolution optical spectroscopy
  53. GRB 020812: optical observation at Kyoto University
  54. Second epoch K band imaging of GRB 020819
  55. GRB020813, Baade 6.5m data now available
  56. GRB 020813 : HST observations
  57. Confirming no variability for GRB02081
  58. GRB020819 : Optical observations at KISO
  59. GRB 020812: early time optical observation at Ouda Station
  60. GRB020813: VRI Decay Slopes
  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. GRB020813, UBVRI field calibration
  68. GRB 020813: addendum to GCN 1498
  69. GRB020813: optical observations at Bisei
  70. GRB020813: V-band decay slope
  71. Polarimetry of GRB020813: evidence for variability
  72. GRB020813 IRAM millimeter observations
  73. GRB020812: optical observations
  74. GRB 020812: optical observation at Bisei
  75. GRB020813: optical observations; possible host galaxy
  76. GRB 020813, radio detection
  77. GRB 020812 : optical afterglow candidate
  78. Millimeter observation of GRB 020813
  79. GRB020812: optical observations
  80. GRB 020813 : KISO multiband optical observations
  81. IPN error box for GRB020813
  82. IPN triangulation of GRB020813
  83. GRB020812: possible afterglow candidate
  84. Early Time Limits for GRB020813
  85. GRB020812: possible afterglow candidate
  86. GRB020813, astrometric position
  87. Spectropolarimetry of GRB 020813
  88. GRB 020813 Afterglow Observations; Possible break
  89. GRB 020813: Absorption redshift
  90. GRB 020813 multiband optical observations
  91. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  92. GRB 020812 optical observation
  93. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  94. GRB 020715, optical observations
  95. GRB 020714, optical observations
  96. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  97. HST Imaging of the Host of GRB 011121
  98. GRB020801, optical afterglow candidate
  99. Further refinement to IPN error box for GRB020531
  100. GRB020331: Late-time Optical Light Curve (re-submission)

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