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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"

36685 results found.

  1. GRB 020409: Optical Observations
  2. Mars Odyssey joins the IPN
  3. IPN triangulation of GRB020413
  4. GRB 020409, 2-nd epoch optical observations at Terskol.
  5. GRB 020409: Optical observations
  6. GRB 020409, No Optical Detection to R = 22
  7. GRB 020409: No Evidence for an Optical Afterglow
  8. GRB 020409, 2nd epoch optical observations
  9. GRB 020331 Kyoto observation on March 31
  10. GRB 020409
  11. GRB 020409 SARA Observations
  12. GRB "020411"
  13. GRB 020409, No Optical Detection to R = 20
  14. GRB020410: BeppoSAX NFI observation
  15. GRB 020409: Optical observations
  16. April 11 BeppoSAX event (GRB020411) is likely not a GRB
  17. GRB 020410, optical observations
  18. BeppoSAX ALERT: possible GRB020411
  19. GRB 020409, optical observations
  20. GRB 020409: Optical Observations
  21. GRB020406(?), optical observations
  22. GRB020410, optical observations
  23. BeppoSAX ALERT: possible GRB020410
  24. X-ray afterglow of GRB020321
  25. BeppoSAX GRB : GRB020409
  26. GRB020405: VLT optical observations and V band decay slope
  27. GRB020331 optical observations with RIMOTS
  28. GRB020124 optical observations with RIBOTS/RIMOTS
  29. GRB 020321: Candidate X-ray Counterparts
  30. ASM GRB candidate 020406 refined error box
  31. GRB 020405: Moderate-resolution spectroscopy
  32. GRB020406(?), optical observations
  33. GRB020405: VLT optical observations
  34. Revised Photometry of the Optical Afterglow of GRB 020405
  35. GRB020405: OT observations
  36. GRB 020331: Candidate Optical Afterglow
  37. GRB 020405: Decay index
  38. Short RXTE/ASM transient 020406; may be a GRB
  39. GRB020405, Radio Observations
  40. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  41. GRB 020405, U-band observations
  42. GRB 020405: Optical afterglow candidate
  43. IPN localization of GRB020405
  44. GRB011212: Optical Observations
  45. GRB 020331: NIR Observations
  46. GRB 020331: NIR Observations
  47. GRB020331 NIR observation at KPNO (re-submission)
  48. GRB02033 NIR observation at KPNO
  49. GRB020331 field photometry
  50. GRB 020331 Optical Observations
  51. GRB 020331, NIR observations
  52. GRB 020331: Optical observations
  53. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  54. GRB 020321: Infrared observations
  55. GRB 020322: BeppoSAX observations of the X-ray afterglow
  56. SN 2002ap - peak brightness date (SN/GRB?)
  57. GRB 020322, Radio observations
  58. Near-Infrared Observations of GRB020322 at TIRGO
  59. GRB 020321, Radio Observations
  60. GRB 020322: Optical Observations
  61. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  62. GRB 020321: Optical observations
  63. GRB020317 BVRI field photometry
  64. GRB011211 revised BVRI field photometry
  65. GRB020305 BVRI field photometry
  66. GRB020322 BVRI field photometry
  67. GRB 020322 optical observations
  68. GRB 020322 optical observation
  69. GRB020317 : Near IR Observations from Mt Abu Observatory
  70. GRB 020322: Optical Sources and Improved Astrometry
  71. GRB020322, optical observations
  72. GRB 020322: Optical candidate
  73. GRB020322: BeppoSAX/NFI Observations
  74. Bepposax GRB020322 The second springtime BSAX GRB
  75. GRB 020321: Optical observations
  76. GRB 011121: Fourth Epoch of HST Imaging
  77. GRB020317: optical observations
  78. GRB020321 optical observations
  79. GRB020321: BeppoSAX/NFI Observations
  80. GRB020321: a faint BeppoSAX detection
  81. GRB 020317 : KISO Optical Observations
  82. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  83. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  84. GRB 020305: Optical Observations
  85. GRB020317, optical observations
  86. GRB 020317: Optical observations
  87. GRB 011121: Third HST Epoch
  88. GRB020305: Properties of the Candidate Optical Afterglow
  89. GRB 011121: HST Observations reveal an intermediate-time multicolor
  90. GRB011121, possible supernova association
  91. GRB011130 (XRF011130) Second Epoch Chandra Observations
  92. GRB020305: Subaru Optical Observations
  93. GRB 020305: Optical observations
  94. XRF/GRB 011030 Images
  95. XRF/GRB 011030: Detection of the Probable Host Galaxy
  96. GRB 020305: Candidate optical afterglow
  97. Type Ic SN2002bl (SN/GRB?) Radio Observations
  98. GRB020305: Optical Observations
  99. IPN triangulation of GRB020305 (HETE 1939)
  100. GRB020305 (=H1939): Localization of a GRB by HETE

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