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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

26312 results found.

  1. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  2. GRB020321 : Optical observations.
  3. GRB020331: Third Epoch and Revised Second Epoch Optical
  4. The end of BSAX GRB activities
  5. GRB 020410, Radio Observations
  6. GRB 020124: Optical observations
  7. IPN triangulation of GRB020418
  8. GRB020405: VLT observations of the OT environment
  9. Mars Odyssey joins the IPN
  10. IPN triangulation of GRB020413
  11. GRB 020409, 2-nd epoch optical observations at Terskol.
  12. GRB020405: predicted break
  13. GRB 020409, No Optical Detection to R = 22
  14. GRB 020409, 2nd epoch optical observations
  15. GRB 020331 Kyoto observation on March 31
  16. GRB 020409, No Optical Detection to R = 20
  17. X-ray afterglow of GRB020321
  18. GRB020331: Confirmation of Afterglow Candidate with Magellan
  19. GRB020405: VLT optical observations and V band decay slope
  20. GRB020331 optical observations with RIMOTS
  21. GRB020124 optical observations with RIBOTS/RIMOTS
  22. ASM GRB candidate 020406 refined error box
  23. GRB020331: Optical Observations of Afterglow Candidate
  24. GRB020405: VLT optical observations
  25. GRB020405: OT observations
  26. GRB 020331: Candidate Optical Afterglow
  27. GRB 020405: Decay index
  28. GRB020405, Radio Observations
  29. V band observations of GRB020405
  30. GRB 020405, U-band observations
  31. IPN localization of GRB020405
  32. GRB011212: Optical Observations
  33. GRB 020331: NIR Observations
  34. GRB 020331, NIR observations
  35. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  36. GRB 020321: Infrared observations
  37. GRB 020322: BeppoSAX observations of the X-ray afterglow
  38. SN 2002ap - peak brightness date (SN/GRB?)
  39. Near-Infrared Observations of GRB020322 at TIRGO
  40. GRB 020322: Optical Observations
  41. GRB011211 revised BVRI field photometry
  42. GRB020305 BVRI field photometry
  43. GRB020322 BVRI field photometry
  44. GRB 020322 optical observations
  45. GRB020317 : Near IR Observations from Mt Abu Observatory
  46. GRB 020322: Optical Sources and Improved Astrometry
  47. GRB020322, optical observations
  48. XMM-Newton observation of GRB020322
  49. GRB020322: Optical Observations
  50. GRB 020321: Optical observations
  51. GRB020317: optical observations
  52. GRB020321: a faint BeppoSAX detection
  53. GRB020305: NIR observations
  54. GRB 020317 : KISO Optical Observations
  55. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  56. GRB 020305: Optical Observations
  57. GRB020317, optical observations
  58. GRB 011121: Third HST Epoch
  59. GRB020305: Properties of the Candidate Optical Afterglow
  60. GRB 011121: HST Observations reveal an intermediate-time multicolor
  61. GRB011121, possible supernova association
  62. GRB011130 (XRF011130) Second Epoch Chandra Observations
  63. GRB020305: Subaru Optical Observations
  64. GRB020305, optical observations
  65. IPN triangulation of GRB020305 (HETE 1939)
  66. GRB020305 (=H1939): Localization of a GRB by HETE
  67. HST Imaging of the afterglow and host of GRB 011121
  68. GRB 010921: HST Observations
  69. IPN detection and localization of Cygnus X-1 flares
  70. RXTE Observations of SGR 1900+14
  71. SGR1900+14 activity
  72. IPN/HETE Detection of Bursts from SGR1900+14
  73. IPN Upper Limits to a GRB Associated With SN2002ap
  74. GRB020124 BVRI field photometry
  75. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  76. SN2002ap (SN/GRB?) Echelle spectra
  77. GRB020127 Optical Observations
  78. SN 2002ap (SN/GRB?)
  79. SN 2002ap in M74
  80. SN2002ap (SN/GRB?) UBVRI Field Photometry
  81. GRB020127: Chandra Observations and Prospective Counterparts
  82. GRB020124, optical observations
  83. GRB020127: Optical observations
  84. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  85. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  86. GRB 020124 Optical Observations
  87. IPN triangulation of GRB020124 (HETE 1896)
  88. GRB 020124: Optical afterglow
  89. GRB020124(=H1896): Localization of a Long GRB by HETE
  90. Possible optical counterpart to a GRB
  91. GRB011211: BeppoSAX/GRBM data
  92. Optical polarization observations for GRB011211
  93. GRB 011211: Detection of the Probable Host Galaxy
  94. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  95. Color indices of the afterglow of GRB011211
  96. GRB011212: Optical observations at Gunma
  97. GRB 011211, spectrum and optical photometry
  98. GRB 011130: Optical Observations of X-ray and Radio Sources
  99. GRB 011130, Radio/X-ray Comparison
  100. GRB 011211: Evidence for an Optical Break

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