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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"

26303 results found.

  1. GRB 021112: Variable Source in R-band search
  2. GRB021112: Optical Observations
  3. GRB021113: Kiso Observations
  4. IPN triangulation of GRB021113 (=H2449; annulus)
  5. GRB 021112: RAPTOR Observations
  6. GRB021113 (=H2449): A Long GRB Localized by HETE
  7. GRB 021112: R-band search
  8. IPN triangulation of GRB021108 (large error box)
  9. GRB021112 (=H2448): A Long GRB Localized by HETE
  10. IPN triangulation of GRB021109 (annulus)
  11. IPN triangulation of GRB021108 (annulus)
  12. IPN triangulation of GRB021104 (annulus)
  13. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  14. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  15. SGR1900+14 activity, November 2-4, 2002
  16. Spectropolarimetry of GRB021004
  17. GRB021104: optical observations
  18. GRB021104: Candidate present in DSS
  19. IPN triangulation of GRB021102 (annulus)
  20. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  21. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  22. IPN triangulation of GRB021025 (portion of annulus)
  23. IPN triangulation of GRB021027 (single large error box)
  24. IPN triangulation of GRB021027 (two large error boxes)
  25. IPN triangulation of GRB021027 (annulus)
  26. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  27. IPN triangulation of GRB021025 (annulus)
  28. IPN triangulation of SGR1900+14, October 22 2002
  29. GRB 021004: optical observations
  30. IPN triangulation of GRB021023 (small error boc)
  31. GRB021004: Optical Observations
  32. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  33. IPN triangulation of GRB021020
  34. GRB 021004: VRI observations at TNG: possible break
  35. SGR1900+14: burst on October 10 2002
  36. GRB 021008, optical observations
  37. GRB021016(=H2397): A Long GRB Localized by HETE
  38. IPN triangulation of GRB021016 (small error box)
  39. GRB021004: Optical Observations
  40. IPN triangulation of GRB021014 (large error box)
  41. GRB 021004: optical spectroscopy on Oct 11
  42. GRB021004: High-resolution optical spectroscopy
  43. IPN triangulation of GRB021013 (annulus)
  44. GRB021004, UBVRcIc field photometry update
  45. IPN triangulation of GRB021008 (single error box)
  46. GRB021004: Optical Observations
  47. IPN triangulation of GRB021008B (annulus)
  48. IPN triangulation of GRB021008 (two small error boxes)
  49. GRB021004 Chandra HETG Observations
  50. GRB 021004: Optical/NIR Observations
  51. GRB 021004: Additional V-band Polarimetric Observations
  52. GRB021004: optical observation
  53. GRB 021004: Host Galaxy Star Formation Rate
  54. GRB 021004: WC wind?
  55. IPN triangulation of GRB021008
  56. GRB021004: NIR and Optical observations
  57. GRB 021004: Optical observations, AUDE network
  58. GRB 021004 - VLA Radio Observations
  59. IPN triangulation of GRB021007 (annulus)
  60. XRF 020903 spectrum
  61. GRB021004: optical observations and predicted break time
  62. GRB021004: restart of optical decay
  63. GRB 021004 continued IR fading
  64. HETE fluences for GRB021004
  65. GRB 021004, spectroscopic observations
  66. GRB 021004: polarimetric observations
  67. GRB 021004: V-band Polarimetric Observations
  68. GRB021004: Update Bisei photometric data
  69. GRB 021004: Optical Decay
  70. GRB021004, astrometric position
  71. IRAM Millimeter detection of GRB 021004
  72. GRB 021004: Optical observations at RIKEN
  73. GRB 021004: Optical Observations
  74. GRB021004, BVRcIc field photometry
  75. GRB021004: Optical Spectroscopy
  76. GRB 021004: Optical Observations
  77. GRB 021004, SPM optical observations
  78. GRB 021004: radio observations
  79. GRB021004: Upper limits from recent and historical observations
  80. GRB021004: optical observations at Nyrola
  81. GRB021004(=H2380): Revised Localization with HETE Soft X-ray
  82. GRB021004: optical observations at Bisei
  83. GRB021004(=H2380): A Long GRB Localized by HETE in Near-Real Time
  84. GRB021004: Optical Afterglow
  85. XRF020903: TNG and Asiago photometry
  86. GRB 020903: Optical observations at RIKEN
  87. XRF 020903: Correction to GCN 1560
  88. XRF 020903: VRI observations
  89. XRF 020903: R band observations
  90. XRF 020903: Archival Optical Images
  91. Radio Observations of XRF 020903: The Missing Link
  92. XRF 020903: Supernova
  93. IPN triangulation of GRB020926 (two large error boxes)
  94. GRB020924 (ecliptic latitude-only localization)
  95. IPN triangulation of GRB020923 (two error boxes)
  96. IPN annulus for GRB020923
  97. IPN triangulation of GRB020914B
  98. IPN triangulation of GRB020918 (annulus)
  99. IPN triangulation of GRB020911 (2 large error boxes)
  100. IPN triangulation of GRB020914 - clarification and additional information

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