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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"

37950 results found.

  1. GRB021004: continued fading
  2. GRB 021004: Optical Photometry at 1.5 Days
  3. GRB021004, Optical Observations
  4. GRB021004, BVRcIc field photometry
  5. GRB 021004: Optical observations
  6. GRB 021004: optical counterpart
  7. GRB 021004, optical observations
  8. GRB021004: Optical Spectroscopy
  9. GRB 021004: Optical Observations
  10. GRB 021004, SPM optical observations
  11. GRB 021004, optical observations
  12. GRB 021004 radio search
  13. GRB 021004: radio observations
  14. GRB 021004: steepening of the optical decay slope
  15. GRB021004: Upper limits from recent and historical observations
  16. XRF020903, BVRI field photometry
  17. GRB021004: optical observations at Nyrola
  18. GRB021004: Absorption redshift
  19. GRB 021004: Kyoto observation
  20. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  21. GRB021004: Optical Afterglow
  22. GRB 020903: Optical observations at RIKEN
  23. IPN triangulation of GRB020926 (single large error box)
  24. GRB 020903: correction to GCN 1557
  25. XRF 020903: R band observations
  26. Radio Observations of XRF 020903: The Missing Link
  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. IPN triangulation of GRB020904
  46. IPN detection of a burst from SGR1900+14
  47. INTEGRAL GRBs added to GCN
  48. GRB020813: High-resolution optical spectroscopy
  49. GRB 020812: optical observation at Kyoto University
  50. Second epoch K band imaging of GRB 020819
  51. GRB020813, Baade 6.5m data now available
  52. GRB 020813 : HST observations
  53. Confirming no variability for GRB02081
  54. GRB020819 : Optical observations at KISO
  55. GRB 020812: early time optical observation at Ouda Station
  56. GRB020813: VRI Decay Slopes
  57. GRB 020819 : OT candidate - confirmation of non variability
  58. GRB 020819: Optical observations
  59. K band observation of GRB 020819
  60. GRB020819: optical observations
  61. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  62. IPN triangulation of GRB020819 (HETE 2275)
  63. GRB020813, UBVRI field calibration
  64. GRB 020813: addendum to GCN 1498
  65. GRB020813: optical observations at Bisei
  66. GRB020813: V-band decay slope
  67. Polarimetry of GRB020813: evidence for variability
  68. GRB020813 IRAM millimeter observations
  69. GRB020812: optical observations
  70. GRB 020812: optical observation at Bisei
  71. GRB020813: optical observations; possible host galaxy
  72. GRB 020813, radio detection
  73. GRB 020812 : optical afterglow candidate
  74. Millimeter observation of GRB 020813
  75. GRB020812: optical observations
  76. GRB 020813 : KISO multiband optical observations
  77. IPN error box for GRB020813
  78. IPN triangulation of GRB020813
  79. GRB020812: possible afterglow candidate
  80. Early Time Limits for GRB020813
  81. GRB020812: possible afterglow candidate
  82. GRB020813, astrometric position
  83. Spectropolarimetry of GRB 020813
  84. GRB 020813 Afterglow Observations; Possible break
  85. GRB 020813: Absorption redshift
  86. GRB 020813 multiband optical observations
  87. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  88. GRB 020812 optical observation
  89. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  90. GRB 020715, optical observations
  91. GRB 020714, optical observations
  92. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  93. HST Imaging of the Host of GRB 011121
  94. GRB020801, optical afterglow candidate
  95. Further refinement to IPN error box for GRB020531
  96. GRB020331: Late-time Optical Light Curve (re-submission)
  97. GRB020331: Late-time Optical Light Curve
  98. GRB 020405: HST observations reveal red bump
  99. IPN triangulation of GRB020714
  100. IPN triangulation of GRB020715 (=GRB150702)

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