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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"

37530 results found.

  1. GRB021004: Optical Afterglow
  2. GRB 020903: Optical observations at RIKEN
  3. IPN triangulation of GRB020926 (single large error box)
  4. GRB 020903: correction to GCN 1557
  5. XRF 020903: R band observations
  6. Radio Observations of XRF 020903: The Missing Link
  7. IPN triangulation of GRB020926 (two large error boxes)
  8. GRB020924 (ecliptic latitude-only localization)
  9. IPN triangulation of GRB020923 (two error boxes)
  10. IPN annulus for GRB020923
  11. IPN triangulation of GRB020914B
  12. Improved IPN position for GRB020918 (two large error boxes)
  13. IPN annulus for GRB020914B
  14. IPN triangulation of GRB020918 (annulus)
  15. IPN triangulation of GRB020911 (2 large error boxes)
  16. IPN triangulation of GRB020914 - clarification and additional information
  17. IPN triangulation of GRB020914
  18. GRB 020305: HST/STIS observations
  19. Confirmation of IPN error box for GRB020910
  20. IPN triangulation of GRB020910
  21. IPN GCN Circulars now to be issued without restriction
  22. Single IPN error box for GRB020904
  23. XRF 020903: optical observation at Kyoto
  24. GRB020322 : HST/STIS observations
  25. IPN triangulation of GRB020904
  26. IPN detection of a burst from SGR1900+14
  27. INTEGRAL GRBs added to GCN
  28. GRB020813: High-resolution optical spectroscopy
  29. GRB 020812: optical observation at Kyoto University
  30. Second epoch K band imaging of GRB 020819
  31. GRB020813, Baade 6.5m data now available
  32. GRB 020813 : HST observations
  33. Confirming no variability for GRB02081
  34. GRB020819 : Optical observations at KISO
  35. GRB 020812: early time optical observation at Ouda Station
  36. GRB020813: VRI Decay Slopes
  37. GRB 020819 : OT candidate - confirmation of non variability
  38. GRB 020819: Optical observations
  39. K band observation of GRB 020819
  40. GRB020819: optical observations
  41. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  42. IPN triangulation of GRB020819 (HETE 2275)
  43. GRB020813, UBVRI field calibration
  44. GRB 020813: addendum to GCN 1498
  45. GRB020813: optical observations at Bisei
  46. GRB020813: V-band decay slope
  47. Polarimetry of GRB020813: evidence for variability
  48. GRB020813 IRAM millimeter observations
  49. GRB020812: optical observations
  50. GRB 020812: optical observation at Bisei
  51. GRB020813: optical observations; possible host galaxy
  52. GRB 020813, radio detection
  53. GRB 020812 : optical afterglow candidate
  54. Millimeter observation of GRB 020813
  55. GRB020812: optical observations
  56. GRB 020813 : KISO multiband optical observations
  57. IPN error box for GRB020813
  58. IPN triangulation of GRB020813
  59. GRB020812: possible afterglow candidate
  60. Early Time Limits for GRB020813
  61. GRB020812: possible afterglow candidate
  62. GRB020813, astrometric position
  63. Spectropolarimetry of GRB 020813
  64. GRB 020813 Afterglow Observations; Possible break
  65. GRB 020813: Absorption redshift
  66. GRB 020813 multiband optical observations
  67. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  68. GRB 020812 optical observation
  69. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  70. GRB 020715, optical observations
  71. GRB 020714, optical observations
  72. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  73. HST Imaging of the Host of GRB 011121
  74. GRB020801, optical afterglow candidate
  75. Further refinement to IPN error box for GRB020531
  76. GRB020331: Late-time Optical Light Curve (re-submission)
  77. GRB020331: Late-time Optical Light Curve
  78. GRB 020405: HST observations reveal red bump
  79. IPN triangulation of GRB020714
  80. IPN triangulation of GRB020715 (=GRB150702)
  81. IPN triangulation of GRB020714
  82. IPN triangulation of GRB150702
  83. GRB 020410: Discovery of Probable OT by HST
  84. GRB 020124, HST observations of the fading afterglow
  85. IPN triangulation of GRB020708
  86. IPN triangulation of GRB020708
  87. IPN error box for GRB020706
  88. IPN triangulation of GRB020706
  89. GRB 020705: Optical observations
  90. GRB 020625, optical observations
  91. GRB 020625: Optical observations
  92. GRB 020531: optical photometry of Chandra sources
  93. GRB020625 (=H2081): A Long Burst Localized by HETE
  94. The Probable Host Galaxy of GRB/XRF 020427
  95. GRB/XRF 020427, detection of an underlying system with the VLT
  96. GRB 020531, INT+WFC deep optical upper limits
  97. GRB020405: polarimetric observations
  98. GRB 020531, simultaneous optical observations
  99. GRB 020604, optical observations
  100. GRB 020531/Candidate Redshift

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