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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"

35431 results found.

  1. GRB 020903: correction to GCN 1557
  2. XRF 020903: R band observations
  3. Radio Observations of XRF 020903: The Missing Link
  4. IPN triangulation of GRB020926 (two large error boxes)
  5. GRB020924 (ecliptic latitude-only localization)
  6. IPN triangulation of GRB020923 (two error boxes)
  7. IPN annulus for GRB020923
  8. IPN triangulation of GRB020914B
  9. Improved IPN position for GRB020918 (two large error boxes)
  10. IPN annulus for GRB020914B
  11. IPN triangulation of GRB020918 (annulus)
  12. IPN triangulation of GRB020911 (2 large error boxes)
  13. IPN triangulation of GRB020914 - clarification and additional information
  14. IPN triangulation of GRB020914
  15. GRB 020305: HST/STIS observations
  16. Confirmation of IPN error box for GRB020910
  17. IPN triangulation of GRB020910
  18. IPN GCN Circulars now to be issued without restriction
  19. Single IPN error box for GRB020904
  20. XRF 020903: optical observation at Kyoto
  21. GRB020322 : HST/STIS observations
  22. IPN triangulation of GRB020904
  23. IPN detection of a burst from SGR1900+14
  24. INTEGRAL GRBs added to GCN
  25. GRB020813: High-resolution optical spectroscopy
  26. GRB 020812: optical observation at Kyoto University
  27. Second epoch K band imaging of GRB 020819
  28. GRB020813, Baade 6.5m data now available
  29. GRB 020813 : HST observations
  30. Confirming no variability for GRB02081
  31. GRB020819 : Optical observations at KISO
  32. GRB 020812: early time optical observation at Ouda Station
  33. GRB020813: VRI Decay Slopes
  34. GRB 020819 : OT candidate - confirmation of non variability
  35. GRB 020819: Optical observations
  36. K band observation of GRB 020819
  37. GRB020819: optical observations
  38. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  39. IPN triangulation of GRB020819 (HETE 2275)
  40. GRB020813, UBVRI field calibration
  41. GRB 020813: addendum to GCN 1498
  42. GRB020813: optical observations at Bisei
  43. GRB020813: V-band decay slope
  44. Polarimetry of GRB020813: evidence for variability
  45. GRB020813 IRAM millimeter observations
  46. GRB020812: optical observations
  47. GRB 020812: optical observation at Bisei
  48. GRB020813: optical observations; possible host galaxy
  49. GRB 020813, radio detection
  50. GRB 020812 : optical afterglow candidate
  51. Millimeter observation of GRB 020813
  52. GRB020812: optical observations
  53. GRB 020813 : KISO multiband optical observations
  54. IPN error box for GRB020813
  55. IPN triangulation of GRB020813
  56. GRB020812: possible afterglow candidate
  57. Early Time Limits for GRB020813
  58. GRB020812: possible afterglow candidate
  59. GRB020813, astrometric position
  60. Spectropolarimetry of GRB 020813
  61. GRB 020813 Afterglow Observations; Possible break
  62. GRB 020813: Absorption redshift
  63. GRB 020813 multiband optical observations
  64. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  65. GRB 020812 optical observation
  66. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  67. GRB 020715, optical observations
  68. GRB 020714, optical observations
  69. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  70. HST Imaging of the Host of GRB 011121
  71. GRB020801, optical afterglow candidate
  72. Further refinement to IPN error box for GRB020531
  73. GRB020331: Late-time Optical Light Curve (re-submission)
  74. GRB020331: Late-time Optical Light Curve
  75. GRB 020405: HST observations reveal red bump
  76. IPN triangulation of GRB020714
  77. IPN triangulation of GRB020715 (=GRB150702)
  78. IPN triangulation of GRB020714
  79. IPN triangulation of GRB150702
  80. GRB 020410: Discovery of Probable OT by HST
  81. GRB 020124, HST observations of the fading afterglow
  82. IPN triangulation of GRB020708
  83. IPN triangulation of GRB020708
  84. IPN error box for GRB020706
  85. IPN triangulation of GRB020706
  86. GRB 020705: Optical observations
  87. GRB 020625, optical observations
  88. GRB 020625: Optical observations
  89. GRB 020531: optical photometry of Chandra sources
  90. GRB020625 (=H2081): A Long Burst Localized by HETE
  91. The Probable Host Galaxy of GRB/XRF 020427
  92. GRB/XRF 020427, detection of an underlying system with the VLT
  93. GRB 020531, INT+WFC deep optical upper limits
  94. GRB020405: polarimetric observations
  95. GRB 020531, simultaneous optical observations
  96. GRB 020604, optical observations
  97. GRB 020531/Candidate Redshift
  98. GRB020531: Second epoch Chandra observations
  99. GRB020604, optical observations
  100. GRB020604, BVRcIc field photometry

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