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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"

35451 results found.

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

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