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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"

2707 results found.

  1. XRF020903: TNG and Asiago photometry
  2. XRF 020903: R band observations
  3. XRF 020903: Archival Optical Images
  4. IPN triangulation of GRB020926 (two large error boxes)
  5. IPN triangulation of GRB020923 (two error boxes)
  6. IPN annulus for GRB020923
  7. IPN triangulation of GRB020914B
  8. Improved IPN position for GRB020918 (two large error boxes)
  9. IPN annulus for GRB020914B
  10. IPN triangulation of GRB020911 (2 large error boxes)
  11. IPN triangulation of GRB020914 - clarification and additional information
  12. IPN triangulation of GRB020910
  13. IPN GCN Circulars now to be issued without restriction
  14. GRB 020813 : HST observations
  15. GRB020813: Magellan BVRI Photometry
  16. GRB020813: High-Resolution Optical Observations
  17. GRB020813: optical observations; possible host galaxy
  18. GRB020812: optical observations
  19. IPN triangulation of GRB020813
  20. GRB020812: possible afterglow candidate
  21. GRB020812: possible afterglow candidate
  22. GRB 020813 Afterglow Observations; Possible break
  23. GRB 020410: Discovery of Probable OT by HST
  24. IPN triangulation of GRB020706
  25. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  26. Fading Optical Source in the Field of GRB020531
  27. GRB 020531, simultaneous optical observations
  28. GRB020531 Optical observations with TAROT
  29. GRB020531 Optical observations with TAROT
  30. IPN triangulation of GRB020604
  31. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  32. IPN triangulation of GRB020603 (possible short/hard GRB)
  33. GRB 020531 optical observations with TAROT
  34. IPN detection of possible bursts from SGR1806-20
  35. GRB020427 BeppoSAX NFI Observation
  36. GRB020405: VLT observations of the OT environment
  37. GRB020405: predicted break
  38. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  39. BeppoSAX ALERT: possible GRB020411
  40. GRB020406(?), optical observations
  41. GRB020410, optical observations
  42. BeppoSAX ALERT: possible GRB020410
  43. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  44. GRB 020321, Radio Observations
  45. GRB020321: BeppoSAX/NFI Observations
  46. GRB 020317: Optical observations
  47. GRB 011121: HST Observations reveal an intermediate-time multicolor
  48. GRB011121, possible supernova association
  49. GRB020127: Further VLA Observations of Possible Counterparts
  50. GRB020127: Palomar and VLA Observations of Possible Counterparts
  51. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  52. SN 2002ap (SN/GRB?)
  53. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  54. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  55. GRB 020124 Optical Observations
  56. GRB optical counterpart candidate in GCN 1217 is M dwarf
  57. Possible optical counterpart to a GRB
  58. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  59. GRB 011130: Magellan spectroscopy
  60. GRB011130, optical observations
  61. GRB 011121: J-band observations
  62. GRB 011121: HST Scheduled
  63. GRB011121: fainter still
  64. GRB011121: continued decay
  65. GRB011121: possible redshift, continued decay
  66. GRB011121: fading behavior
  67. GRB011121: possible optical counterpart
  68. GRB 011030 I-band Observation
  69. GRB 011030, WSRT radio observations
  70. BeppoSAX ALERT: Possible X-ray rich GRB011030
  71. GRB 010921: Possible supernova component
  72. GRB010921: Spectroscopy of the Host Galaxy
  73. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  74. IPN triangulation of GRB010921 (=H1761)
  75. GCN and HETE status
  76. GRB010629: Optical Observations
  77. Possible burst from SGR1806-20
  78. IPN triangulation of GRB010613
  79. HETE Fully-Automated GCN Notices
  80. GRB010214, optical observations
  81. SGR1900+14
  82. Possible precursor to the SGR1900+14 giant burst
  83. Further Optical Observations of GRB 010324
  84. GRB 010222, Optical Observations
  85. Sub-millimeter Excess/GRB 010222
  86. GRB010222: R-band data
  87. GRB010222, possible increase of optical decay slope
  88. GRB010222: Optical Observations
  89. GRB010222: possible optical counterpart
  90. GRB010222
  91. GRB 010214, Optical Observations
  92. GRB010214, Radio Observations
  93. GRB010214, optical observations
  94. Possible InfraRed Transient of GRB 010214.
  95. GRB010126 optical observations
  96. IPN TRIANGULATION OF GRB010126
  97. GRB 001212 Optical Observation
  98. GRB 001212 possible OA in 2MASS
  99. GRB 001212 possible OA
  100. Confirmation of IPN position for GRB001204

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