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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"

16219 results found.

  1. GRB020405 field photometry at ESO
  2. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  3. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  4. XRF 020427
  5. GRB 020124: Optical observations
  6. GRB020405: VLT observations of the OT environment
  7. GRB 020409: No Evidence for an Optical Afterglow
  8. GRB 020331 Kyoto observation on March 31
  9. X-ray afterglow of GRB020321
  10. BeppoSAX GRB : GRB020409
  11. GRB020331 optical observations with RIMOTS
  12. GRB020124 optical observations with RIBOTS/RIMOTS
  13. GRB020406(?), optical observations
  14. GRB020405, Radio Observations
  15. GRB 020405, U-band observations
  16. GRB020331 NIR observation at KPNO (re-submission)
  17. GRB02033 NIR observation at KPNO
  18. GRB020331 field photometry
  19. GRB 020331, NIR observations
  20. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  21. GRB 020322: BeppoSAX observations of the X-ray afterglow
  22. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  23. Near-Infrared Observations of GRB020322 at TIRGO
  24. GRB 020322: Optical Observations
  25. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  26. GRB 020321: Optical observations
  27. GRB020317 BVRI field photometry
  28. GRB011211 revised BVRI field photometry
  29. GRB020305 BVRI field photometry
  30. GRB020322 BVRI field photometry
  31. GRB020322: Candidate Optical Afterglow
  32. GRB 020322: Optical Sources and Improved Astrometry
  33. GRB020317: optical observations
  34. GRB020321 optical observations
  35. GRB020321: a faint BeppoSAX detection
  36. GRB 020317 : KISO Optical Observations
  37. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  38. GRB 020305: Optical Observations
  39. GRB020317, optical observations
  40. GRB 020317: Optical observations
  41. GRB020305: Properties of the Candidate Optical Afterglow
  42. GRB011130 (XRF011130) Second Epoch Chandra Observations
  43. GRB 020305: Optical observations
  44. XRF/GRB 011030: Detection of the Probable Host Galaxy
  45. GRB 020305: Candidate optical afterglow
  46. GRB020305, optical observations
  47. HST Imaging of the afterglow and host of GRB 011121
  48. GRB 010921: HST Observations
  49. SGR1900+14 activity
  50. GRB020124 BVRI field photometry
  51. GRB020127 Optical Observations
  52. SN2002ap (SN/GRB?) UBVRI Field Photometry
  53. GRB020127: Chandra Observations and Prospective Counterparts
  54. pre-SN2002ap (SN/GRB?) imaging of M74
  55. GRB020124, optical observations
  56. GRB 020127, I-band observations starting 3.14-hr after the event
  57. GRB010921 Optical Observations
  58. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  59. GRB020124: Optical observations
  60. GRB020124: Optical observations
  61. GRB 020124: Optical observations
  62. GRB 020124: Optical afterglow
  63. GRB020124(=H1896): Localization of a Long GRB by HETE
  64. Possible optical counterpart to a GRB
  65. GRB011212, Optical Observations
  66. Optical polarization observations for GRB011211
  67. GRB 011130: Optical Observations of X-ray and Radio Sources
  68. GRB 011130, Radio/X-ray Comparison
  69. GRB 011212: optical observation at Asiago
  70. GRB 011211: Evidence for an Optical Break
  71. GRB 011212: optical observation at Oslo (relayed)
  72. GRB 011211, Optical Observations
  73. GRB011212, BVRI field photometry
  74. GRB011211, BVRI field photometry
  75. Fading of the optical source associated of XRF 011211
  76. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  77. GRB011130 (XRF011130) Chandra Observations
  78. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  79. GRB 011130, K band observations
  80. GRB011130 (XRF011130) SDSS PT i-band observations
  81. XRF011130: Infrared Observations
  82. GRB 011121: J-band observations
  83. GRB 011121: NIR observations, host galaxy?
  84. GRB011121: UBRI Observations
  85. GRB 011121 J-Band Astrometry
  86. GRB 011121: Detection of Bright IR Counterpart
  87. GRB011121: possible redshift, continued decay
  88. GRB 011030: TNG K-band observation
  89. XRF011030: J and K band observations
  90. XRF011030: Chandra Observations
  91. GRB011030: Z-band observations
  92. Non-triggered burst 011030 ("GRB 011030")
  93. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  94. GRB 970828: HST Observations of the Host Galaxy
  95. GRB 000131: HST Detection of the Host Galaxy
  96. GRB 970828: HST Observations of the Host Galaxy
  97. GRB010921, optical observation
  98. GRB011019: Subaru Optical Observations
  99. GRB011030 - further refinement WFC position
  100. GRB011030: radio search

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