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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"

37107 results found.

  1. GRB 021004: Optical Photometry at 2.5 Days
  2. GRB 021004: polarimetric observations
  3. GRB 021004: V-band Polarimetric Observations
  4. GRB 021004: Optical Decay
  5. GRB021004, astrometric position
  6. GRB021004, Optical Observations
  7. IRAM Millimeter detection of GRB 021004
  8. GRB 021004: Optical observations at RIKEN
  9. GRB 021004 radio observation
  10. GRB 021004: Optical Observations
  11. GRB021004: continued fading
  12. GRB 021004: Optical Photometry at 1.5 Days
  13. GRB021004, Optical Observations
  14. GRB021004, BVRcIc field photometry
  15. GRB 021004: Optical observations
  16. GRB 021004: optical counterpart
  17. GRB 021004, optical observations
  18. GRB021004: Optical Spectroscopy
  19. GRB 021004: Optical Observations
  20. GRB 021004, SPM optical observations
  21. GRB 021004, optical observations
  22. GRB 021004 radio search
  23. GRB 021004: radio observations
  24. GRB 021004: steepening of the optical decay slope
  25. GRB021004: Upper limits from recent and historical observations
  26. XRF020903, BVRI field photometry
  27. GRB021004: optical observations at Nyrola
  28. GRB021004: Absorption redshift
  29. GRB 021004: Kyoto observation
  30. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  31. GRB021004: Optical Afterglow
  32. GRB 020903: Optical observations at RIKEN
  33. IPN triangulation of GRB020926 (single large error box)
  34. GRB 020903: correction to GCN 1557
  35. XRF 020903: R band observations
  36. Radio Observations of XRF 020903: The Missing Link
  37. XRF 020903: Supernova
  38. IPN triangulation of GRB020926 (two large error boxes)
  39. GRB020924 (ecliptic latitude-only localization)
  40. IPN triangulation of GRB020923 (two error boxes)
  41. IPN annulus for GRB020923
  42. IPN triangulation of GRB020914B
  43. Improved IPN position for GRB020918 (two large error boxes)
  44. IPN annulus for GRB020914B
  45. IPN triangulation of GRB020918 (annulus)
  46. IPN triangulation of GRB020911 (2 large error boxes)
  47. IPN triangulation of GRB020914 - clarification and additional information
  48. IPN triangulation of GRB020914
  49. GRB 020305: HST/STIS observations
  50. Confirmation of IPN error box for GRB020910
  51. IPN triangulation of GRB020910
  52. IPN GCN Circulars now to be issued without restriction
  53. Single IPN error box for GRB020904
  54. XRF 020903: optical observation at Kyoto
  55. GRB020322 : HST/STIS observations
  56. IPN triangulation of GRB020904
  57. IPN detection of a burst from SGR1900+14
  58. INTEGRAL GRBs added to GCN
  59. SGR1900+14 burst localized by HETE
  60. GRB020813: High-resolution optical spectroscopy
  61. GRB 020812: optical observation at Kyoto University
  62. Second epoch K band imaging of GRB 020819
  63. GRB020813, Baade 6.5m data now available
  64. GRB 020813 : HST observations
  65. Confirming no variability for GRB02081
  66. GRB020819 : Optical observations at KISO
  67. GRB 020812: early time optical observation at Ouda Station
  68. GRB020813: VRI Decay Slopes
  69. GRB 020819 : OT candidate - confirmation of non variability
  70. GRB 020819: Optical observations
  71. K band observation of GRB 020819
  72. GRB020819: optical observations
  73. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  74. IPN triangulation of GRB020819 (HETE 2275)
  75. GRB020813, UBVRI field calibration
  76. GRB 020813: addendum to GCN 1498
  77. GRB020813: optical observations at Bisei
  78. GRB020813: V-band decay slope
  79. Polarimetry of GRB020813: evidence for variability
  80. GRB020813 IRAM millimeter observations
  81. GRB020812: optical observations
  82. GRB020813: High-Resolution Optical Observations
  83. GRB 020812: optical observation at Bisei
  84. GRB020813: Early Time Magnitude
  85. GRB020813: optical observations; possible host galaxy
  86. GRB 020813, radio detection
  87. GRB 020812 : optical afterglow candidate
  88. Millimeter observation of GRB 020813
  89. GRB020812: optical observations
  90. GRB 020813 : KISO multiband optical observations
  91. IPN error box for GRB020813
  92. IPN triangulation of GRB020813
  93. GRB020812: possible afterglow candidate
  94. Early Time Limits for GRB020813
  95. GRB020812: possible afterglow candidate
  96. GRB020813, astrometric position
  97. Spectropolarimetry of GRB 020813
  98. GRB 020813 Afterglow Observations; Possible break
  99. GRB 020813: Absorption redshift
  100. GRB 020813 multiband optical observations

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