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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"

41069 results found.

  1. SGR1900+14: burst on October 10 2002
  2. GRB 021008, optical observations
  3. GRB021016(=H2397): A Long GRB Localized by HETE
  4. IPN triangulation of GRB021016 (small error box)
  5. GRB021004: Optical Observations
  6. GRB 021004: optical spectroscopy on Oct 11
  7. IPN triangulation of GRB021013 (two small error boxes)
  8. GRB021004: High-resolution optical spectroscopy
  9. IPN triangulation of GRB021013 (annulus)
  10. XRF 020903: flattening of the optical light curve.
  11. GRB021004, UBVRcIc field photometry update
  12. GRB021004: Optical Observations
  13. GRB 021004 submm observations
  14. IPN triangulation of GRB021008B (annulus)
  15. GRB021004 Chandra HETG Observations
  16. GRB 021004: Optical/NIR Observations
  17. GRB 021004: Additional V-band Polarimetric Observations
  18. GRB021004: optical observation
  19. GRB 021004: Host Galaxy Star Formation Rate
  20. GRB 021004 submm observations
  21. GRB 021004: WC wind?
  22. IPN triangulation of GRB021008
  23. GRB021004: NIR and Optical observations
  24. GRB 021004: Optical measurement at OHP
  25. GRB 021004: Optical observations, AUDE network
  26. GRB 021004 - VLA Radio Observations
  27. GRB 021004 - Unusual Radio-to-Submm Spectrum
  28. GRB 021004: optical spectroscopy
  29. IPN triangulation of GRB021007 (annulus)
  30. XRF 020903 spectrum
  31. GRB 021004: HST/STIS spectroscopic observations
  32. GRB021004: optical observations and predicted break time
  33. GRB021004: BVRc photometry
  34. GRB 021004 redshift
  35. GRB021004 radio observation
  36. GRB021004: restart of optical decay
  37. GRB 021004: Optical Decay
  38. GRB 021004 continued IR fading
  39. HETE fluences for GRB021004
  40. GRB 021004, spectroscopic observations
  41. GRB021004: not fading anymore?
  42. GRB 021004: Optical Photometry at 2.5 Days
  43. GRB 021004: polarimetric observations
  44. GRB 021004: V-band Polarimetric Observations
  45. GRB 021004: Optical Decay
  46. GRB021004, astrometric position
  47. GRB021004, Optical Observations
  48. IRAM Millimeter detection of GRB 021004
  49. GRB 021004: Optical observations at RIKEN
  50. GRB 021004 radio observation
  51. GRB 021004: Optical Observations
  52. GRB021004: continued fading
  53. GRB 021004: Optical Photometry at 1.5 Days
  54. GRB021004, Optical Observations
  55. GRB021004, BVRcIc field photometry
  56. GRB 021004: Optical observations
  57. GRB 021004: optical counterpart
  58. GRB 021004, optical observations
  59. GRB021004: Optical Spectroscopy
  60. GRB 021004: Optical Observations
  61. GRB 021004, SPM optical observations
  62. GRB 021004, optical observations
  63. GRB 021004 radio search
  64. GRB 021004: radio observations
  65. GRB 021004: steepening of the optical decay slope
  66. GRB021004: Upper limits from recent and historical observations
  67. XRF020903, BVRI field photometry
  68. GRB021004: optical observations at Nyrola
  69. GRB021004: Absorption redshift
  70. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  71. GRB021004: optical observations at Bisei
  72. GRB 021004: Kyoto observation
  73. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  74. GRB021004: Optical Afterglow
  75. XRF020903: TNG and Asiago photometry
  76. GRB 020903: Optical observations at RIKEN
  77. XRF 020903: Correction to GCN 1560
  78. XRF 020903: VRI observations
  79. IPN triangulation of GRB020926 (single large error box)
  80. XRF 020903: R band observations
  81. XRF 020903: Archival Optical Images
  82. Radio Observations of XRF 020903: The Missing Link
  83. XRF 020903: Supernova
  84. IPN triangulation of GRB020926 (two large error boxes)
  85. GRB020924 (ecliptic latitude-only localization)
  86. IPN annulus for GRB020923
  87. IPN triangulation of GRB020914B
  88. Improved IPN position for GRB020918 (two large error boxes)
  89. IPN annulus for GRB020914B
  90. IPN triangulation of GRB020911 (2 large error boxes)
  91. IPN triangulation of GRB020914 - clarification and additional information
  92. IPN triangulation of GRB020914
  93. GRB 020305: HST/STIS observations
  94. IPN GCN Circulars now to be issued without restriction
  95. XRF 020903: optical observation at Kyoto
  96. GRB020322 : HST/STIS observations
  97. XRF 020903: Optical observations
  98. IPN triangulation of GRB020904
  99. XRF 020903: Optical observations
  100. IPN detection of a burst from SGR1900+14

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