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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"

26299 results found.

  1. GRB 021112: RAPTOR Observations
  2. GRB021113 (=H2449): A Long GRB Localized by HETE
  3. GRB 021112: R-band search
  4. IPN triangulation of GRB021108 (large error box)
  5. GRB021112 (=H2448): A Long GRB Localized by HETE
  6. IPN triangulation of GRB021109 (annulus)
  7. IPN triangulation of GRB021108 (annulus)
  8. IPN triangulation of GRB021104 (annulus)
  9. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  10. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  11. SGR1900+14 activity, November 2-4, 2002
  12. Spectropolarimetry of GRB021004
  13. GRB021104: optical observations
  14. GRB021104: Candidate present in DSS
  15. IPN triangulation of GRB021102 (annulus)
  16. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  17. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  18. IPN triangulation of GRB021025 (portion of annulus)
  19. IPN triangulation of GRB021027 (single large error box)
  20. IPN triangulation of GRB021027 (two large error boxes)
  21. IPN triangulation of GRB021027 (annulus)
  22. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  23. IPN triangulation of GRB021025 (annulus)
  24. IPN triangulation of SGR1900+14, October 22 2002
  25. GRB 021004: optical observations
  26. IPN triangulation of GRB021023 (small error boc)
  27. GRB021004: Optical Observations
  28. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  29. IPN triangulation of GRB021020
  30. GRB 021004: VRI observations at TNG: possible break
  31. SGR1900+14: burst on October 10 2002
  32. GRB 021008, optical observations
  33. GRB021016(=H2397): A Long GRB Localized by HETE
  34. IPN triangulation of GRB021016 (small error box)
  35. GRB021004: Optical Observations
  36. IPN triangulation of GRB021014 (large error box)
  37. GRB 021004: optical spectroscopy on Oct 11
  38. GRB021004: High-resolution optical spectroscopy
  39. IPN triangulation of GRB021013 (annulus)
  40. GRB021004, UBVRcIc field photometry update
  41. IPN triangulation of GRB021008 (single error box)
  42. GRB021004: Optical Observations
  43. IPN triangulation of GRB021008B (annulus)
  44. IPN triangulation of GRB021008 (two small error boxes)
  45. GRB021004 Chandra HETG Observations
  46. GRB 021004: Optical/NIR Observations
  47. GRB 021004: Additional V-band Polarimetric Observations
  48. GRB021004: optical observation
  49. GRB 021004: Host Galaxy Star Formation Rate
  50. GRB 021004: WC wind?
  51. IPN triangulation of GRB021008
  52. GRB021004: NIR and Optical observations
  53. GRB 021004: Optical observations, AUDE network
  54. GRB 021004 - VLA Radio Observations
  55. IPN triangulation of GRB021007 (annulus)
  56. XRF 020903 spectrum
  57. GRB021004: optical observations and predicted break time
  58. GRB021004: restart of optical decay
  59. GRB 021004 continued IR fading
  60. HETE fluences for GRB021004
  61. GRB 021004, spectroscopic observations
  62. GRB 021004: polarimetric observations
  63. GRB 021004: V-band Polarimetric Observations
  64. GRB021004: Update Bisei photometric data
  65. GRB 021004: Optical Decay
  66. GRB021004, astrometric position
  67. IRAM Millimeter detection of GRB 021004
  68. GRB 021004: Optical observations at RIKEN
  69. GRB 021004: Optical Observations
  70. GRB021004, BVRcIc field photometry
  71. GRB021004: Optical Spectroscopy
  72. GRB 021004: Optical Observations
  73. GRB 021004, SPM optical observations
  74. GRB 021004: radio observations
  75. GRB021004: Upper limits from recent and historical observations
  76. GRB021004: optical observations at Nyrola
  77. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  78. GRB021004: optical observations at Bisei
  79. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  80. GRB021004: Optical Afterglow
  81. XRF020903: TNG and Asiago photometry
  82. GRB 020903: Optical observations at RIKEN
  83. XRF 020903: Correction to GCN 1560
  84. XRF 020903: VRI observations
  85. XRF 020903: R band observations
  86. XRF 020903: Archival Optical Images
  87. Radio Observations of XRF 020903: The Missing Link
  88. XRF 020903: Supernova
  89. IPN triangulation of GRB020926 (two large error boxes)
  90. GRB020924 (ecliptic latitude-only localization)
  91. IPN triangulation of GRB020923 (two error boxes)
  92. IPN annulus for GRB020923
  93. IPN triangulation of GRB020914B
  94. IPN triangulation of GRB020918 (annulus)
  95. IPN triangulation of GRB020911 (2 large error boxes)
  96. IPN triangulation of GRB020914 - clarification and additional information
  97. IPN triangulation of GRB020910
  98. IPN GCN Circulars now to be issued without restriction
  99. GRB020322 : HST/STIS observations
  100. XRF 020903: Optical observations

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