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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"

35278 results found.

  1. GRB 020409, 2nd epoch optical observations
  2. GRB 020331 Kyoto observation on March 31
  3. GRB 020409
  4. GRB 020409 SARA Observations
  5. GRB "020411"
  6. GRB 020409, No Optical Detection to R = 20
  7. GRB020410: BeppoSAX NFI observation
  8. GRB 020409: Optical observations
  9. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  10. GRB 020410, optical observations
  11. BeppoSAX ALERT: possible GRB020411
  12. GRB 020409, optical observations
  13. GRB 020409: Optical Observations
  14. GRB020406(?), optical observations
  15. GRB020410, optical observations
  16. BeppoSAX ALERT: possible GRB020410
  17. X-ray afterglow of GRB020321
  18. BeppoSAX GRB : GRB020409
  19. GRB020405: VLT optical observations and V band decay slope
  20. GRB020331 optical observations with RIMOTS
  21. GRB020124 optical observations with RIBOTS/RIMOTS
  22. GRB 020321: Candidate X-ray Counterparts
  23. ASM GRB candidate 020406 refined error box
  24. GRB 020405: Moderate-resolution spectroscopy
  25. GRB020406(?), optical observations
  26. GRB020405: VLT optical observations
  27. Revised Photometry of the Optical Afterglow of GRB 020405
  28. GRB020405: OT observations
  29. GRB 020331: Candidate Optical Afterglow
  30. GRB 020405: Decay index
  31. Short RXTE/ASM transient 020406; may be a GRB
  32. GRB020405, Radio Observations
  33. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  34. GRB 020405, U-band observations
  35. GRB 020405: Optical afterglow candidate
  36. IPN localization of GRB020405
  37. GRB011212: Optical Observations
  38. GRB 020331: NIR Observations
  39. GRB 020331: NIR Observations
  40. GRB020331 NIR observation at KPNO (re-submission)
  41. GRB02033 NIR observation at KPNO
  42. GRB020331 field photometry
  43. GRB 020331 Optical Observations
  44. GRB 020331, NIR observations
  45. GRB 020331: Optical observations
  46. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  47. GRB 020321: Infrared observations
  48. GRB 020322: BeppoSAX observations of the X-ray afterglow
  49. SN 2002ap - peak brightness date (SN/GRB?)
  50. GRB 020322, Radio observations
  51. Near-Infrared Observations of GRB020322 at TIRGO
  52. GRB 020321, Radio Observations
  53. GRB 020322: Optical Observations
  54. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  55. GRB 020321: Optical observations
  56. GRB020317 BVRI field photometry
  57. GRB011211 revised BVRI field photometry
  58. GRB020305 BVRI field photometry
  59. GRB020322 BVRI field photometry
  60. GRB 020322 optical observations
  61. GRB 020322 optical observation
  62. GRB020317 : Near IR Observations from Mt Abu Observatory
  63. GRB 020322: Optical Sources and Improved Astrometry
  64. GRB020322, optical observations
  65. GRB 020322: Optical candidate
  66. GRB020322: BeppoSAX/NFI Observations
  67. Bepposax GRB020322 The second springtime BSAX GRB
  68. GRB 020321: Optical observations
  69. GRB 011121: Fourth Epoch of HST Imaging
  70. GRB020317: optical observations
  71. GRB020321 optical observations
  72. GRB020321: BeppoSAX/NFI Observations
  73. GRB020321: a faint BeppoSAX detection
  74. GRB 020317 : KISO Optical Observations
  75. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  76. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  77. GRB 020305: Optical Observations
  78. GRB020317, optical observations
  79. GRB 020317: Optical observations
  80. GRB 011121: Third HST Epoch
  81. GRB020305: Properties of the Candidate Optical Afterglow
  82. GRB 011121: HST Observations reveal an intermediate-time multicolor
  83. GRB011121, possible supernova association
  84. GRB011130 (XRF011130) Second Epoch Chandra Observations
  85. GRB020305: Subaru Optical Observations
  86. GRB 020305: Optical observations
  87. XRF/GRB 011030 Images
  88. XRF/GRB 011030: Detection of the Probable Host Galaxy
  89. GRB 020305: Candidate optical afterglow
  90. Type Ic SN2002bl (SN/GRB?) Radio Observations
  91. GRB020305: Optical Observations
  92. IPN triangulation of GRB020305 (HETE 1939)
  93. GRB020305 (=H1939): Localization of a GRB by HETE
  94. GRB 020305: Optical observations
  95. HST Imaging of the afterglow and host of GRB 011121
  96. GRB 010921: HST Observations
  97. IPN detection and localization of Cygnus X-1 flares
  98. GRB020127: Further VLA Observations of Possible Counterparts
  99. IPN detection of further SGR1900+14 activity
  100. SGR1900+14 activity

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