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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"

23417 results found.

  1. GRB 021204: I-band Observations
  2. IPN triangulation of GRB021206 (small error box)
  3. IPN triangulation of GRB021205 (large error box)
  4. GRB021201, BVRcIc field photometry
  5. GRB 021201, Radio Observations
  6. GRB 021201: BOOTES simultaneous optical observations
  7. IPN triangulation of GRB021201 (short/hard burst, small error box)
  8. GRB021004, late time optical observations
  9. IPN detection of continued SGR1900+14 activity
  10. IPN triangulation of GRB021115 (annulus)
  11. IPN triangulation of GRB021125B (two large error boxes)
  12. IPN triangulation of GRB021119 (large error box)
  13. IPN triangulation of GRB021125B (annulus)
  14. Improved IPN error box for GRB021125
  15. IPN BURST POSITION
  16. IPN triangulation of GRB021125 (INTEGRAL BURST)
  17. GRB021125 : A long GRB localized by INTEGRAL
  18. IPN triangulation of GRB021119 (annulus)
  19. GRB 021112: Afterglow or Variable Star?
  20. GRB021113: optical observations at Bisei
  21. GRB 021113: Evidence for a Dark Optical Afterglow
  22. GRB 021112, Radio Observations
  23. GRB021112, BVRI field photometry
  24. GRB 021112: Variable Source in R-band search
  25. GRB021112: Optical Observations
  26. GRB021113: Kiso Observations
  27. IPN triangulation of GRB021109 (portion of annulus)
  28. IPN triangulation of GRB021113 (=H2449; annulus)
  29. IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
  30. GRB 021113: Optical observations
  31. GRB 021112: RAPTOR Observations
  32. IPN triangulation of GRB021108 (large error box)
  33. GRB021112 (=H2448): A Long GRB Localized by HETE
  34. GRB 021016: Optical Observations
  35. IPN triangulation of GRB021109 (annulus)
  36. IPN triangulation of GRB021108 (annulus)
  37. GRB021004: Near infrared spectroscopy
  38. IPN triangulation of GRB021104 (annulus)
  39. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  40. SGR1900+14 activity, November 2-4, 2002
  41. GRB021104: optical observations
  42. GRB021104: possible optical afterglow
  43. IPN triangulation of GRB021102 (annulus)
  44. Detection of activity from SGR 1900+14 with the RXTE/PCA
  45. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  46. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  47. IPN triangulation of GRB021025 (portion of annulus)
  48. IPN triangulation of GRB021027 (single large error box)
  49. GRB021004, late-time optical observations
  50. IPN triangulation of GRB021027 (annulus)
  51. IPN triangulation of GRB021025 (annulus)
  52. IPN triangulation of GRB021023 (small error boc)
  53. IPN triangulation of GRB021020 (smaller error box)
  54. IPN triangulation of GRB021020
  55. SGR1900+14: burst on October 10 2002
  56. GRB 021008, optical observations
  57. IPN triangulation of GRB021016 (small error box)
  58. IPN triangulation of GRB021014 (large error box)
  59. IPN triangulation of GRB021013 (single error box)
  60. IPN triangulation of GRB021013 (two small error boxes)
  61. XRF 020903: flattening of the optical light curve.
  62. GRB021004, UBVRcIc field photometry update
  63. IPN triangulation of GRB021008 (single error box)
  64. GRB 021004 submm observations
  65. IPN triangulation of GRB021008B (annulus)
  66. IPN triangulation of GRB021008 (two small error boxes)
  67. GRB 021004: Optical/NIR Observations
  68. GRB 021004: Additional V-band Polarimetric Observations
  69. GRB021004: optical observation
  70. GRB 021004: Host Galaxy Star Formation Rate
  71. GRB 021004 submm observations
  72. GRB021004: NIR and Optical observations
  73. GRB 021004 - VLA Radio Observations
  74. GRB 021004 - Unusual Radio-to-Submm Spectrum
  75. GRB 021004: optical spectroscopy
  76. IPN triangulation of GRB021007 (annulus)
  77. GRB021004: BVRc photometry
  78. GRB021004 radio observation
  79. GRB021004: restart of optical decay
  80. HETE fluences for GRB021004
  81. GRB 021004, spectroscopic observations
  82. GRB 021004: Optical Photometry at 2.5 Days
  83. GRB 021004: polarimetric observations
  84. GRB 021004: V-band Polarimetric Observations
  85. GRB021004: Update Bisei photometric data
  86. GRB 021004: Optical observations at RIKEN
  87. GRB 021004 radio observation
  88. GRB 021004: Optical Photometry at 1.5 Days
  89. GRB021004, BVRcIc field photometry
  90. GRB021004: Optical Spectroscopy
  91. GRB 021004 radio search
  92. GRB021004: Upper limits from recent and historical observations
  93. XRF020903, BVRI field photometry
  94. XRF020903: TNG and Asiago photometry
  95. GRB 020903: Optical observations at RIKEN
  96. XRF 020903: Correction to GCN 1560
  97. XRF 020903: VRI observations
  98. IPN triangulation of GRB020926 (single large error box)
  99. XRF 020903: R band observations
  100. XRF 020903: Supernova

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