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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"

35267 results found.

  1. GRB021004: optical observations and predicted break time
  2. GRB 021004 redshift
  3. GRB 021004: Optical Decay
  4. GRB 021004 continued IR fading
  5. HETE fluences for GRB021004
  6. GRB 021004, spectroscopic observations
  7. GRB021004: not fading anymore?
  8. GRB 021004: Optical Photometry at 2.5 Days
  9. GRB 021004: polarimetric observations
  10. GRB 021004: V-band Polarimetric Observations
  11. GRB 021004: Optical Decay
  12. GRB021004, astrometric position
  13. GRB021004, Optical Observations
  14. IRAM Millimeter detection of GRB 021004
  15. GRB 021004: Optical observations at RIKEN
  16. GRB 021004 radio observation
  17. GRB 021004: Optical Observations
  18. GRB021004: continued fading
  19. GRB 021004: Optical Photometry at 1.5 Days
  20. GRB021004, Optical Observations
  21. GRB021004, BVRcIc field photometry
  22. GRB 021004: Optical observations
  23. GRB 021004: optical counterpart
  24. GRB 021004, optical observations
  25. GRB021004: Optical Spectroscopy
  26. GRB 021004: Optical Observations
  27. GRB 021004, SPM optical observations
  28. GRB 021004, optical observations
  29. GRB 021004 radio search
  30. GRB 021004: radio observations
  31. GRB 021004: steepening of the optical decay slope
  32. GRB021004: Upper limits from recent and historical observations
  33. XRF020903, BVRI field photometry
  34. GRB021004: optical observations at Nyrola
  35. GRB021004: Absorption redshift
  36. GRB 021004: Kyoto observation
  37. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  38. GRB021004: Optical Afterglow
  39. GRB 020903: Optical observations at RIKEN
  40. IPN triangulation of GRB020926 (single large error box)
  41. GRB 020903: correction to GCN 1557
  42. XRF 020903: R band observations
  43. Radio Observations of XRF 020903: The Missing Link
  44. IPN triangulation of GRB020926 (two large error boxes)
  45. GRB020924 (ecliptic latitude-only localization)
  46. IPN triangulation of GRB020923 (two error boxes)
  47. IPN annulus for GRB020923
  48. IPN triangulation of GRB020914B
  49. Improved IPN position for GRB020918 (two large error boxes)
  50. IPN annulus for GRB020914B
  51. IPN triangulation of GRB020918 (annulus)
  52. IPN triangulation of GRB020911 (2 large error boxes)
  53. IPN triangulation of GRB020914 - clarification and additional information
  54. IPN triangulation of GRB020914
  55. GRB 020305: HST/STIS observations
  56. Confirmation of IPN error box for GRB020910
  57. IPN triangulation of GRB020910
  58. IPN GCN Circulars now to be issued without restriction
  59. Single IPN error box for GRB020904
  60. XRF 020903: optical observation at Kyoto
  61. GRB020322 : HST/STIS observations
  62. IPN triangulation of GRB020904
  63. IPN detection of a burst from SGR1900+14
  64. INTEGRAL GRBs added to GCN
  65. GRB020813: High-resolution optical spectroscopy
  66. GRB 020812: optical observation at Kyoto University
  67. Second epoch K band imaging of GRB 020819
  68. GRB020813, Baade 6.5m data now available
  69. GRB 020813 : HST observations
  70. Confirming no variability for GRB02081
  71. GRB020819 : Optical observations at KISO
  72. GRB 020812: early time optical observation at Ouda Station
  73. GRB020813: VRI Decay Slopes
  74. GRB 020819 : OT candidate - confirmation of non variability
  75. GRB 020819: Optical observations
  76. K band observation of GRB 020819
  77. GRB020819: optical observations
  78. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  79. IPN triangulation of GRB020819 (HETE 2275)
  80. GRB020813, UBVRI field calibration
  81. GRB 020813: addendum to GCN 1498
  82. GRB020813: optical observations at Bisei
  83. GRB020813: V-band decay slope
  84. Polarimetry of GRB020813: evidence for variability
  85. GRB020813 IRAM millimeter observations
  86. GRB020812: optical observations
  87. GRB 020812: optical observation at Bisei
  88. GRB020813: optical observations; possible host galaxy
  89. GRB 020813, radio detection
  90. GRB 020812 : optical afterglow candidate
  91. Millimeter observation of GRB 020813
  92. GRB020812: optical observations
  93. GRB 020813 : KISO multiband optical observations
  94. IPN error box for GRB020813
  95. IPN triangulation of GRB020813
  96. GRB020812: possible afterglow candidate
  97. Early Time Limits for GRB020813
  98. GRB020812: possible afterglow candidate
  99. GRB020813, astrometric position
  100. Spectropolarimetry of GRB 020813

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