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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"

42618 results found.

  1. IPN triangulation of GRB021013 (single error box)
  2. GRB 021004: optical spectroscopy on Oct 11
  3. IPN triangulation of GRB021013 (two small error boxes)
  4. GRB021004: High-resolution optical spectroscopy
  5. IPN triangulation of GRB021013 (annulus)
  6. XRF 020903: flattening of the optical light curve.
  7. GRB021004, UBVRcIc field photometry update
  8. IPN triangulation of GRB021008 (single error box)
  9. GRB021004: Optical Observations
  10. GRB 021004 submm observations
  11. IPN triangulation of GRB021008B (annulus)
  12. IPN triangulation of GRB021008 (two small error boxes)
  13. GRB021004 Chandra HETG Observations
  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. GRB021004: NIR and Optical observations
  22. GRB 021004: Optical measurement at OHP
  23. GRB 021004: Optical observations, AUDE network
  24. GRB 021004 - VLA Radio Observations
  25. GRB 021004 - Unusual Radio-to-Submm Spectrum
  26. GRB 021004: optical spectroscopy
  27. IPN triangulation of GRB021007 (annulus)
  28. XRF 020903 spectrum
  29. GRB 021004: HST/STIS spectroscopic observations
  30. GRB021004: optical observations and predicted break time
  31. GRB021004: BVRc photometry
  32. GRB 021004 redshift
  33. GRB021004 radio observation
  34. GRB021004: restart of optical decay
  35. GRB 021004 continued IR fading
  36. HETE fluences for GRB021004
  37. GRB 021004, spectroscopic observations
  38. GRB021004: not fading anymore?
  39. GRB 021004: Optical Photometry at 2.5 Days
  40. GRB 021004: polarimetric observations
  41. GRB 021004: V-band Polarimetric Observations
  42. GRB 021004: Optical Decay
  43. GRB021004, astrometric position
  44. GRB021004, Optical Observations
  45. IRAM Millimeter detection of GRB 021004
  46. GRB 021004: Optical observations at RIKEN
  47. GRB 021004 radio observation
  48. GRB 021004: Optical Observations
  49. GRB 021004: Optical Photometry at 1.5 Days
  50. GRB021004, BVRcIc field photometry
  51. GRB 021004: Optical observations
  52. GRB 021004: optical counterpart
  53. GRB 021004, optical observations
  54. GRB021004: Optical Spectroscopy
  55. GRB 021004: Optical Observations
  56. GRB 021004, optical observations
  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. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  64. GRB021004: optical observations at Bisei
  65. GRB 021004: Kyoto observation
  66. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  67. GRB021004: Optical Afterglow
  68. XRF020903: TNG and Asiago photometry
  69. GRB 020903: Optical observations at RIKEN
  70. XRF 020903: Correction to GCN 1560
  71. XRF 020903: VRI observations
  72. IPN triangulation of GRB020926 (single large error box)
  73. XRF 020903: R band observations
  74. XRF 020903: Archival Optical Images
  75. Radio Observations of XRF 020903: The Missing Link
  76. XRF 020903: Supernova
  77. IPN triangulation of GRB020926 (two large error boxes)
  78. GRB020924 (ecliptic latitude-only localization)
  79. IPN triangulation of GRB020923 (two error boxes)
  80. IPN annulus for GRB020923
  81. IPN triangulation of GRB020914B
  82. Improved IPN position for GRB020918 (two large error boxes)
  83. IPN annulus for GRB020914B
  84. IPN triangulation of GRB020918 (annulus)
  85. IPN triangulation of GRB020911 (2 large error boxes)
  86. IPN triangulation of GRB020914 - clarification and additional information
  87. IPN triangulation of GRB020914
  88. GRB 020305: HST/STIS observations
  89. Confirmation of IPN error box for GRB020910
  90. IPN triangulation of GRB020910
  91. IPN GCN Circulars now to be issued without restriction
  92. Single IPN error box for GRB020904
  93. XRF 020903: optical observation at Kyoto
  94. GRB020322 : HST/STIS observations
  95. XRF 020903: Optical observations
  96. IPN triangulation of GRB020904
  97. XRF 020903: Optical observations
  98. IPN detection of a burst from SGR1900+14
  99. XRF 020903, optical observations
  100. GRB020903(=H2314): An X-Ray Flash Localized by HETE

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