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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"
  1. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  2. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  3. IPN triangulation of a burst from SGR1806-20
  4. GRB/XRF 020427, Radio Observations
  5. HST detection of the likely host galaxy of GRB 020124
  6. GRB020405 field photometry at ESO
  7. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  8. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  9. GRB020321 : Optical observations.
  10. GRB020427 BeppoSAX NFI Observation
  11. XRF 020427
  12. GRB020331: Third Epoch and Revised Second Epoch Optical
  13. The end of BSAX GRB activities
  14. GRB 020410, Radio Observations
  15. GRB 020418: Optical observations
  16. GRB 020124: Optical observations
  17. GRB 020418: Optical observations
  18. IPN triangulation of GRB020418
  19. GRB020405: VLT observations of the OT environment
  20. GRB020410: BeppoSAX NFI observations refined analysis
  21. GRB 020409: Optical Observations
  22. Mars Odyssey joins the IPN
  23. IPN triangulation of GRB020413
  24. GRB 020409, 2-nd epoch optical observations at Terskol.
  25. GRB020405: predicted break
  26. GRB 020409: Optical observations
  27. GRB 020409, No Optical Detection to R = 22
  28. GRB020410: second BeppoSAX NFI observation
  29. GRB 020409: No Evidence for an Optical Afterglow
  30. GRB 020409, 2nd epoch optical observations
  31. GRB 020331 Kyoto observation on March 31
  32. GRB 020409
  33. GRB 020409 SARA Observations
  34. GRB "020411"
  35. GRB 020409, No Optical Detection to R = 20
  36. GRB020410: BeppoSAX NFI observation
  37. GRB 020409: Optical observations
  38. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  39. GRB 020410, optical observations
  40. BeppoSAX ALERT: possible GRB020411
  41. GRB 020409, optical observations
  42. GRB 020409: Optical Observations
  43. GRB020406(?), optical observations
  44. GRB020410, optical observations
  45. BeppoSAX ALERT: possible GRB020410
  46. X-ray afterglow of GRB020321
  47. BeppoSAX GRB : GRB020409
  48. GRB020331: Confirmation of Afterglow Candidate with Magellan
  49. GRB020405: VLT optical observations and V band decay slope
  50. GRB020331 optical observations with RIMOTS
  51. GRB020124 optical observations with RIBOTS/RIMOTS
  52. GRB 020321: Candidate X-ray Counterparts
  53. ASM GRB candidate 020406 refined error box
  54. GRB 020405: Moderate-resolution spectroscopy
  55. GRB020331: Optical Observations of Afterglow Candidate
  56. GRB020406(?), optical observations
  57. GRB020405: VLT optical observations
  58. Revised Photometry of the Optical Afterglow of GRB 020405
  59. GRB020405: OT observations
  60. GRB 020331: Candidate Optical Afterglow
  61. GRB 020405: Decay index
  62. Short RXTE/ASM transient 020406; may be a GRB
  63. GRB020405, Radio Observations
  64. GRB020405: VLT spectroscopy
  65. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  66. V band observations of GRB020405
  67. GRB 020405, U-band observations
  68. GRB 020405: Optical afterglow candidate
  69. IPN localization of GRB020405
  70. GRB011212: Optical Observations
  71. GRB 020331: NIR Observations
  72. GRB 020331: NIR Observations
  73. GRB020331 NIR observation at KPNO (re-submission)
  74. GRB02033 NIR observation at KPNO
  75. GRB020331 field photometry
  76. GRB 020331 Optical Observations
  77. GRB 020331, NIR observations
  78. GRB 020331: Optical observations
  79. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  80. GRB 020321: Infrared observations
  81. GRB 020322: BeppoSAX observations of the X-ray afterglow
  82. SN 2002ap - peak brightness date (SN/GRB?)
  83. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  84. GRB 020322, Radio observations
  85. Near-Infrared Observations of GRB020322 at TIRGO
  86. GRB 020321, Radio Observations
  87. GRB 020322: Optical Observations
  88. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  89. GRB 020321: Optical observations
  90. GRB020317 BVRI field photometry
  91. GRB011211 revised BVRI field photometry
  92. GRB020305 BVRI field photometry
  93. GRB020322 BVRI field photometry
  94. GRB 020322 optical observations
  95. GRB020322: Candidate Optical Afterglow
  96. GRB 020322 optical observation
  97. GRB020317 : Near IR Observations from Mt Abu Observatory
  98. GRB 020322: Optical Sources and Improved Astrometry
  99. GRB020322, optical observations
  100. GRB 020322: Optical candidate

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