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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"

36145 results found.

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

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