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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"

37794 results found.

  1. GRB021016(=H2397): A Long GRB Localized by HETE
  2. IPN triangulation of GRB021016 (small error box)
  3. IPN triangulation of GRB021014 (large error box)
  4. IPN triangulation of GRB021013 (single error box)
  5. GRB 021004: optical spectroscopy on Oct 11
  6. IPN triangulation of GRB021013 (two small error boxes)
  7. GRB021004: High-resolution optical spectroscopy
  8. IPN triangulation of GRB021013 (annulus)
  9. GRB021004, UBVRcIc field photometry update
  10. IPN triangulation of GRB021008 (single error box)
  11. GRB 021004 submm observations
  12. IPN triangulation of GRB021008B (annulus)
  13. IPN triangulation of GRB021008 (two small error boxes)
  14. GRB 021004: Optical/NIR Observations
  15. GRB 021004: Additional V-band Polarimetric Observations
  16. GRB021004: optical observation
  17. GRB 021004: Host Galaxy Star Formation Rate
  18. GRB 021004 submm observations
  19. GRB 021004: WC wind?
  20. IPN triangulation of GRB021008
  21. GRB 021004: Optical measurement at OHP
  22. GRB 021004: Optical observations, AUDE network
  23. GRB 021004 - VLA Radio Observations
  24. GRB 021004 - Unusual Radio-to-Submm Spectrum
  25. GRB 021004: optical spectroscopy
  26. IPN triangulation of GRB021007 (annulus)
  27. GRB 021004: HST/STIS spectroscopic observations
  28. GRB021004: optical observations and predicted break time
  29. GRB 021004 redshift
  30. GRB 021004: Optical Decay
  31. GRB 021004 continued IR fading
  32. HETE fluences for GRB021004
  33. GRB 021004, spectroscopic observations
  34. GRB021004: not fading anymore?
  35. GRB 021004: Optical Photometry at 2.5 Days
  36. GRB 021004: polarimetric observations
  37. GRB 021004: V-band Polarimetric Observations
  38. GRB 021004: Optical Decay
  39. GRB021004, astrometric position
  40. GRB021004, Optical Observations
  41. IRAM Millimeter detection of GRB 021004
  42. GRB 021004: Optical observations at RIKEN
  43. GRB 021004 radio observation
  44. GRB 021004: Optical Observations
  45. GRB021004: continued fading
  46. GRB 021004: Optical Photometry at 1.5 Days
  47. GRB021004, Optical Observations
  48. GRB021004, BVRcIc field photometry
  49. GRB 021004: Optical observations
  50. GRB 021004: optical counterpart
  51. GRB 021004, optical observations
  52. GRB021004: Optical Spectroscopy
  53. GRB 021004: Optical Observations
  54. GRB 021004, SPM optical observations
  55. GRB 021004, optical observations
  56. GRB 021004 radio search
  57. GRB 021004: radio observations
  58. GRB 021004: steepening of the optical decay slope
  59. GRB021004: Upper limits from recent and historical observations
  60. XRF020903, BVRI field photometry
  61. GRB021004: optical observations at Nyrola
  62. GRB021004: Absorption redshift
  63. GRB 021004: Kyoto observation
  64. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  65. GRB021004: Optical Afterglow
  66. GRB 020903: Optical observations at RIKEN
  67. IPN triangulation of GRB020926 (single large error box)
  68. GRB 020903: correction to GCN 1557
  69. XRF 020903: R band observations
  70. Radio Observations of XRF 020903: The Missing Link
  71. IPN triangulation of GRB020926 (two large error boxes)
  72. GRB020924 (ecliptic latitude-only localization)
  73. IPN triangulation of GRB020923 (two error boxes)
  74. IPN annulus for GRB020923
  75. IPN triangulation of GRB020914B
  76. Improved IPN position for GRB020918 (two large error boxes)
  77. IPN annulus for GRB020914B
  78. IPN triangulation of GRB020918 (annulus)
  79. IPN triangulation of GRB020911 (2 large error boxes)
  80. IPN triangulation of GRB020914 - clarification and additional information
  81. IPN triangulation of GRB020914
  82. GRB 020305: HST/STIS observations
  83. Confirmation of IPN error box for GRB020910
  84. IPN triangulation of GRB020910
  85. IPN GCN Circulars now to be issued without restriction
  86. Single IPN error box for GRB020904
  87. XRF 020903: optical observation at Kyoto
  88. GRB020322 : HST/STIS observations
  89. IPN triangulation of GRB020904
  90. IPN detection of a burst from SGR1900+14
  91. INTEGRAL GRBs added to GCN
  92. GRB020813: High-resolution optical spectroscopy
  93. GRB 020812: optical observation at Kyoto University
  94. Second epoch K band imaging of GRB 020819
  95. GRB020813, Baade 6.5m data now available
  96. GRB 020813 : HST observations
  97. Confirming no variability for GRB02081
  98. GRB020819 : Optical observations at KISO
  99. GRB 020812: early time optical observation at Ouda Station
  100. GRB020813: VRI Decay Slopes

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