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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"

42824 results found.

  1. GRB021004, UBVRcIc field photometry update
  2. IPN triangulation of GRB021008 (single error box)
  3. GRB021004: Optical Observations
  4. GRB 021004 submm observations
  5. IPN triangulation of GRB021008B (annulus)
  6. IPN triangulation of GRB021008 (two small error boxes)
  7. GRB021004 Chandra HETG Observations
  8. GRB 021004: Optical/NIR Observations
  9. GRB 021004: Additional V-band Polarimetric Observations
  10. GRB021004: optical observation
  11. GRB 021004: Host Galaxy Star Formation Rate
  12. GRB 021004 submm observations
  13. GRB 021004: WC wind?
  14. IPN triangulation of GRB021008
  15. GRB021004: NIR and Optical observations
  16. GRB 021004: Optical measurement at OHP
  17. GRB 021004: Optical observations, AUDE network
  18. GRB 021004 - VLA Radio Observations
  19. GRB 021004 - Unusual Radio-to-Submm Spectrum
  20. GRB 021004: optical spectroscopy
  21. IPN triangulation of GRB021007 (annulus)
  22. XRF 020903 spectrum
  23. GRB 021004: HST/STIS spectroscopic observations
  24. GRB021004: optical observations and predicted break time
  25. GRB021004: BVRc photometry
  26. GRB 021004 redshift
  27. GRB021004: restart of optical decay
  28. GRB 021004: Optical Decay
  29. GRB 021004 continued IR fading
  30. HETE fluences for GRB021004
  31. GRB 021004, spectroscopic observations
  32. GRB021004: not fading anymore?
  33. GRB 021004: Optical Photometry at 2.5 Days
  34. GRB 021004: polarimetric observations
  35. GRB 021004: V-band Polarimetric Observations
  36. GRB021004: Update Bisei photometric data
  37. GRB 021004: Optical Decay
  38. GRB021004, astrometric position
  39. GRB021004, Optical Observations
  40. IRAM Millimeter detection of GRB 021004
  41. GRB 021004: Optical observations at RIKEN
  42. GRB 021004: Optical Observations
  43. GRB021004: continued fading
  44. GRB 021004: Optical Photometry at 1.5 Days
  45. GRB021004, Optical Observations
  46. GRB021004, BVRcIc field photometry
  47. GRB 021004: Optical observations
  48. GRB 021004: optical counterpart
  49. GRB 021004, optical observations
  50. GRB021004: Optical Spectroscopy
  51. GRB 021004: Optical Observations
  52. GRB 021004, SPM optical observations
  53. GRB 021004, optical observations
  54. GRB 021004: radio observations
  55. GRB 021004: steepening of the optical decay slope
  56. GRB021004: Upper limits from recent and historical observations
  57. XRF020903, BVRI field photometry
  58. GRB021004: optical observations at Nyrola
  59. GRB021004: Absorption redshift
  60. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  61. GRB021004: optical observations at Bisei
  62. GRB 021004: Kyoto observation
  63. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  64. GRB021004: Optical Afterglow
  65. XRF020903: TNG and Asiago photometry
  66. GRB 020903: Optical observations at RIKEN
  67. XRF 020903: Correction to GCN 1560
  68. XRF 020903: VRI observations
  69. IPN triangulation of GRB020926 (single large error box)
  70. XRF 020903: R band observations
  71. XRF 020903: Archival Optical Images
  72. Radio Observations of XRF 020903: The Missing Link
  73. XRF 020903: Supernova
  74. IPN triangulation of GRB020926 (two large error boxes)
  75. GRB020924 (ecliptic latitude-only localization)
  76. IPN triangulation of GRB020923 (two error boxes)
  77. IPN annulus for GRB020923
  78. IPN triangulation of GRB020914B
  79. Improved IPN position for GRB020918 (two large error boxes)
  80. IPN annulus for GRB020914B
  81. IPN triangulation of GRB020918 (annulus)
  82. IPN triangulation of GRB020911 (2 large error boxes)
  83. IPN triangulation of GRB020914 - clarification and additional information
  84. IPN triangulation of GRB020914
  85. GRB 020305: HST/STIS observations
  86. Confirmation of IPN error box for GRB020910
  87. IPN triangulation of GRB020910
  88. IPN GCN Circulars now to be issued without restriction
  89. Single IPN error box for GRB020904
  90. XRF 020903: optical observation at Kyoto
  91. GRB020322 : HST/STIS observations
  92. XRF 020903: Optical observations
  93. IPN triangulation of GRB020904
  94. XRF 020903: Optical observations
  95. IPN detection of a burst from SGR1900+14
  96. XRF 020903, optical observations
  97. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  98. INTEGRAL GRBs added to GCN
  99. GRB020813: optical observation
  100. GRB020812: optical observation

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