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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"

24795 results found.

  1. GRB021201, BVRcIc field photometry
  2. GRB 021201: BOOTES simultaneous optical observations
  3. IPN triangulation of GRB021201 (short/hard burst, small error box)
  4. GRB021004, late time optical observations
  5. GRB021004 Chandra Observation
  6. IPN detection of continued SGR1900+14 activity
  7. Improved IPN error box for GRB021125
  8. IPN BURST POSITION
  9. IPN triangulation of GRB021125 (INTEGRAL BURST)
  10. GRB021125 : A long GRB localized by INTEGRAL
  11. IPN confirmation of the reactivation of SGR1900+14
  12. GRB021113, SPI ACS observation
  13. GRB 021112: Afterglow or Variable Star?
  14. GRB021113: optical observations at Bisei
  15. GRB 021113: Evidence for a Dark Optical Afterglow
  16. GRB021112, BVRI field photometry
  17. GRB 021112: Variable Source in R-band search
  18. GRB021112: Optical Observations
  19. IPN triangulation of GRB021113 (=H2449; annulus)
  20. GRB 021113: Optical observations
  21. GRB 021112: RAPTOR Observations
  22. GRB021113 (=H2449): A Long GRB Localized by HETE
  23. GRB021112 (=H2448): A Long GRB Localized by HETE
  24. GRB 021016: Optical Observations
  25. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  26. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  27. SGR1900+14 activity, November 2-4, 2002
  28. GRB021104: optical observations
  29. Detection of activity from SGR 1900+14 with the RXTE/PCA
  30. IPN triangulation of GRB021027 (single large error box)
  31. IPN triangulation of GRB021027 (two large error boxes)
  32. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  33. GRB 021004: optical observations
  34. IPN triangulation of GRB021023 (small error boc)
  35. GRB 020813; likely host galaxy.
  36. IPN triangulation of GRB021020 (smaller error box)
  37. IPN triangulation of GRB021020
  38. GRB 021008, optical observations
  39. IPN triangulation of GRB021016 (small error box)
  40. IPN triangulation of GRB021014 (large error box)
  41. IPN triangulation of GRB021013 (single error box)
  42. GRB 021004: optical spectroscopy on Oct 11
  43. IPN triangulation of GRB021013 (two small error boxes)
  44. GRB021004: High-resolution optical spectroscopy
  45. XRF 020903: flattening of the optical light curve.
  46. GRB021004, UBVRcIc field photometry update
  47. IPN triangulation of GRB021008 (single error box)
  48. GRB 021004 submm observations
  49. IPN triangulation of GRB021008 (two small error boxes)
  50. GRB021004 Chandra HETG Observations
  51. GRB 021004: Optical/NIR Observations
  52. GRB 021004: Additional V-band Polarimetric Observations
  53. GRB021004: optical observation
  54. GRB 021004: Host Galaxy Star Formation Rate
  55. GRB 021004 submm observations
  56. GRB 021004: WC wind?
  57. GRB021004: NIR and Optical observations
  58. GRB 021004: Optical observations, AUDE network
  59. GRB 021004 - VLA Radio Observations
  60. GRB 021004 - Unusual Radio-to-Submm Spectrum
  61. GRB 021004: optical spectroscopy
  62. IPN triangulation of GRB021007 (annulus)
  63. GRB021004: optical observations and predicted break time
  64. GRB021004: BVRc photometry
  65. GRB021004 radio observation
  66. HETE fluences for GRB021004
  67. GRB 021004: Optical Photometry at 2.5 Days
  68. GRB 021004: polarimetric observations
  69. GRB 021004: V-band Polarimetric Observations
  70. GRB021004: Update Bisei photometric data
  71. IRAM Millimeter detection of GRB 021004
  72. GRB 021004 radio observation
  73. GRB 021004: Optical Photometry at 1.5 Days
  74. GRB021004, BVRcIc field photometry
  75. GRB021004: Optical Spectroscopy
  76. GRB 021004 radio search
  77. XRF020903, BVRI field photometry
  78. XRF020903: TNG and Asiago photometry
  79. GRB 020903: Optical observations at RIKEN
  80. XRF 020903: Correction to GCN 1560
  81. XRF 020903: VRI observations
  82. XRF 020903: R band observations
  83. XRF 020903: Archival Optical Images
  84. Radio Observations of XRF 020903: The Missing Link
  85. XRF 020903: Supernova
  86. IPN triangulation of GRB020923 (two error boxes)
  87. IPN triangulation of GRB020914B
  88. IPN triangulation of GRB020911 (2 large error boxes)
  89. GRB 020305: HST/STIS observations
  90. Confirmation of IPN error box for GRB020910
  91. IPN triangulation of GRB020910
  92. IPN GCN Circulars now to be issued without restriction
  93. Single IPN error box for GRB020904
  94. XRF 020903: optical observation at Kyoto
  95. GRB020322 : HST/STIS observations
  96. XRF 020903: Optical observations
  97. IPN triangulation of GRB020904
  98. INTEGRAL GRBs added to GCN
  99. SGR1900+14 burst localized by HETE
  100. GRB020813: High-resolution optical spectroscopy

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