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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"

35940 results found.

  1. GRB 021004, optical observations
  2. GRB 021004 radio search
  3. GRB 021004: radio observations
  4. GRB 021004: steepening of the optical decay slope
  5. GRB021004: Upper limits from recent and historical observations
  6. XRF020903, BVRI field photometry
  7. GRB021004: optical observations at Nyrola
  8. GRB021004: Absorption redshift
  9. GRB 021004: Kyoto observation
  10. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  11. GRB021004: Optical Afterglow
  12. GRB 020903: Optical observations at RIKEN
  13. IPN triangulation of GRB020926 (single large error box)
  14. GRB 020903: correction to GCN 1557
  15. XRF 020903: R band observations
  16. Radio Observations of XRF 020903: The Missing Link
  17. IPN triangulation of GRB020926 (two large error boxes)
  18. GRB020924 (ecliptic latitude-only localization)
  19. IPN triangulation of GRB020923 (two error boxes)
  20. IPN annulus for GRB020923
  21. IPN triangulation of GRB020914B
  22. Improved IPN position for GRB020918 (two large error boxes)
  23. IPN annulus for GRB020914B
  24. IPN triangulation of GRB020918 (annulus)
  25. IPN triangulation of GRB020911 (2 large error boxes)
  26. IPN triangulation of GRB020914 - clarification and additional information
  27. IPN triangulation of GRB020914
  28. GRB 020305: HST/STIS observations
  29. Confirmation of IPN error box for GRB020910
  30. IPN triangulation of GRB020910
  31. IPN GCN Circulars now to be issued without restriction
  32. Single IPN error box for GRB020904
  33. XRF 020903: optical observation at Kyoto
  34. GRB020322 : HST/STIS observations
  35. IPN triangulation of GRB020904
  36. IPN detection of a burst from SGR1900+14
  37. INTEGRAL GRBs added to GCN
  38. GRB020813: High-resolution optical spectroscopy
  39. GRB 020812: optical observation at Kyoto University
  40. Second epoch K band imaging of GRB 020819
  41. GRB020813, Baade 6.5m data now available
  42. GRB 020813 : HST observations
  43. Confirming no variability for GRB02081
  44. GRB020819 : Optical observations at KISO
  45. GRB 020812: early time optical observation at Ouda Station
  46. GRB020813: VRI Decay Slopes
  47. GRB 020819 : OT candidate - confirmation of non variability
  48. GRB 020819: Optical observations
  49. K band observation of GRB 020819
  50. GRB020819: optical observations
  51. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  52. IPN triangulation of GRB020819 (HETE 2275)
  53. GRB020813, UBVRI field calibration
  54. GRB 020813: addendum to GCN 1498
  55. GRB020813: optical observations at Bisei
  56. GRB020813: V-band decay slope
  57. Polarimetry of GRB020813: evidence for variability
  58. GRB020813 IRAM millimeter observations
  59. GRB020812: optical observations
  60. GRB 020812: optical observation at Bisei
  61. GRB020813: optical observations; possible host galaxy
  62. GRB 020813, radio detection
  63. GRB 020812 : optical afterglow candidate
  64. Millimeter observation of GRB 020813
  65. GRB020812: optical observations
  66. GRB 020813 : KISO multiband optical observations
  67. IPN error box for GRB020813
  68. IPN triangulation of GRB020813
  69. GRB020812: possible afterglow candidate
  70. Early Time Limits for GRB020813
  71. GRB020812: possible afterglow candidate
  72. GRB020813, astrometric position
  73. Spectropolarimetry of GRB 020813
  74. GRB 020813 Afterglow Observations; Possible break
  75. GRB 020813: Absorption redshift
  76. GRB 020813 multiband optical observations
  77. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  78. GRB 020812 optical observation
  79. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  80. GRB 020715, optical observations
  81. GRB 020714, optical observations
  82. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  83. HST Imaging of the Host of GRB 011121
  84. GRB020801, optical afterglow candidate
  85. Further refinement to IPN error box for GRB020531
  86. GRB020331: Late-time Optical Light Curve (re-submission)
  87. GRB020331: Late-time Optical Light Curve
  88. GRB 020405: HST observations reveal red bump
  89. IPN triangulation of GRB020714
  90. IPN triangulation of GRB020715 (=GRB150702)
  91. IPN triangulation of GRB020714
  92. IPN triangulation of GRB150702
  93. GRB 020410: Discovery of Probable OT by HST
  94. GRB 020124, HST observations of the fading afterglow
  95. IPN triangulation of GRB020708
  96. IPN triangulation of GRB020708
  97. IPN error box for GRB020706
  98. IPN triangulation of GRB020706
  99. GRB 020705: Optical observations
  100. GRB 020625, optical observations

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