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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"

24999 results found.

  1. GRB021211 - Upper limits from recent and historical observations
  2. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  3. IPN triangulation of GRB021206 (small error box)
  4. IPN triangulation of GRB021205 (large error box)
  5. GRB021201, BVRcIc field photometry
  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. GRB021004 Chandra Observation
  10. IPN detection of continued SGR1900+14 activity
  11. Improved IPN error box for GRB021125
  12. IPN BURST POSITION
  13. IPN triangulation of GRB021125 (INTEGRAL BURST)
  14. GRB021125 : A long GRB localized by INTEGRAL
  15. IPN confirmation of the reactivation of SGR1900+14
  16. GRB021113, SPI ACS observation
  17. GRB 021112: Afterglow or Variable Star?
  18. GRB021113: optical observations at Bisei
  19. GRB 021113: Evidence for a Dark Optical Afterglow
  20. GRB021112, BVRI field photometry
  21. GRB 021112: Variable Source in R-band search
  22. GRB021112: Optical Observations
  23. IPN triangulation of GRB021113 (=H2449; annulus)
  24. GRB 021113: Optical observations
  25. GRB 021112: RAPTOR Observations
  26. GRB021113 (=H2449): A Long GRB Localized by HETE
  27. GRB021112 (=H2448): A Long GRB Localized by HETE
  28. GRB 021016: Optical Observations
  29. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  30. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  31. SGR1900+14 activity, November 2-4, 2002
  32. GRB021104: optical observations
  33. Detection of activity from SGR 1900+14 with the RXTE/PCA
  34. IPN triangulation of GRB021027 (single large error box)
  35. IPN triangulation of GRB021027 (two large error boxes)
  36. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  37. GRB 021004: optical observations
  38. IPN triangulation of GRB021023 (small error boc)
  39. GRB 020813; likely host galaxy.
  40. IPN triangulation of GRB021020 (smaller error box)
  41. IPN triangulation of GRB021020
  42. GRB 021008, optical observations
  43. IPN triangulation of GRB021016 (small error box)
  44. IPN triangulation of GRB021014 (large error box)
  45. IPN triangulation of GRB021013 (single error box)
  46. GRB 021004: optical spectroscopy on Oct 11
  47. IPN triangulation of GRB021013 (two small error boxes)
  48. GRB021004: High-resolution optical spectroscopy
  49. XRF 020903: flattening of the optical light curve.
  50. GRB021004, UBVRcIc field photometry update
  51. IPN triangulation of GRB021008 (single error box)
  52. GRB 021004 submm observations
  53. IPN triangulation of GRB021008 (two small error boxes)
  54. GRB021004 Chandra HETG Observations
  55. GRB 021004: Optical/NIR Observations
  56. GRB 021004: Additional V-band Polarimetric Observations
  57. GRB021004: optical observation
  58. GRB 021004: Host Galaxy Star Formation Rate
  59. GRB 021004 submm observations
  60. GRB 021004: WC wind?
  61. GRB021004: NIR and Optical observations
  62. GRB 021004: Optical observations, AUDE network
  63. GRB 021004 - VLA Radio Observations
  64. GRB 021004 - Unusual Radio-to-Submm Spectrum
  65. GRB 021004: optical spectroscopy
  66. IPN triangulation of GRB021007 (annulus)
  67. GRB021004: optical observations and predicted break time
  68. GRB021004: BVRc photometry
  69. GRB021004 radio observation
  70. HETE fluences for GRB021004
  71. GRB 021004: Optical Photometry at 2.5 Days
  72. GRB 021004: polarimetric observations
  73. GRB 021004: V-band Polarimetric Observations
  74. GRB021004: Update Bisei photometric data
  75. IRAM Millimeter detection of GRB 021004
  76. GRB 021004 radio observation
  77. GRB 021004: Optical Photometry at 1.5 Days
  78. GRB021004, BVRcIc field photometry
  79. GRB021004: Optical Spectroscopy
  80. GRB 021004 radio search
  81. XRF020903, BVRI field photometry
  82. XRF020903: TNG and Asiago photometry
  83. GRB 020903: Optical observations at RIKEN
  84. XRF 020903: Correction to GCN 1560
  85. XRF 020903: VRI observations
  86. XRF 020903: R band observations
  87. XRF 020903: Archival Optical Images
  88. Radio Observations of XRF 020903: The Missing Link
  89. XRF 020903: Supernova
  90. IPN triangulation of GRB020923 (two error boxes)
  91. IPN triangulation of GRB020914B
  92. IPN triangulation of GRB020911 (2 large error boxes)
  93. GRB 020305: HST/STIS observations
  94. Confirmation of IPN error box for GRB020910
  95. IPN triangulation of GRB020910
  96. IPN GCN Circulars now to be issued without restriction
  97. Single IPN error box for GRB020904
  98. XRF 020903: optical observation at Kyoto
  99. GRB020322 : HST/STIS observations
  100. XRF 020903: Optical observations

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