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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"

26055 results found.

  1. GRB 000528 - WFC measurements
  2. GRB000519, BVRI field photometry
  3. IPN triangulation of GRB000519
  4. GRB000508B, optical photometry
  5. GRB000508B, BVR field photometry
  6. Possible GRB-related phenomenon
  7. RXTE/ASM and IPN localization of GRB 000508B
  8. GRB000424, UBVRI field photometry
  9. GRB000418, UBVRI field photometry update
  10. GRB000424, optical observations
  11. GRB 000429, optical observation
  12. GRB 000429, UBVRI field photometry
  13. GRB 000418, UBVRI field photometry
  14. GRB 000418, optical observation
  15. GRB 000418, Optical Observation
  16. GRB000418, near-infrared observations
  17. Correction to IPN error box for GRB000419
  18. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  19. GRB000416 BRJK observations
  20. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  21. GRB 000408, optical observations
  22. GRB 991208, UBVRI field photometry
  23. GRB000408, lotis optical observations
  24. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  25. GRB000301C - Addendum to GCN 623
  26. GRB 000323, optical observations
  27. GRB 000326: Optical Observations
  28. GRB000326, Radio observations
  29. GRB000313, Radio observations
  30. GRB 000313 - optical transient in the BATSE error box
  31. GRB 000307, Optical Observations
  32. GRB 000307, BVRI Field Photometry
  33. GRB 000301C: A Precise Redshift Determination
  34. GRB 000301C, Optical Observation
  35. GRB 000301C: HST/STIS CCD Imaging of the field
  36. IPN error box for GRB000307
  37. GRB000301C, optical R-band observations
  38. GRB 000301C Optical Observations
  39. GRB 000301C: K' Observations
  40. GRB000301C OT candidate optical observations
  41. GRB000301C - Host galaxy not detected in R (?)
  42. Optical observations of GRB000301c
  43. GRB000301C, Radio observations
  44. GRB000301C, Radio observations
  45. GRB000301C, near-infrared observations (JHK' imaging)
  46. GRB 000301c near-IR observations
  47. GRB 000301C, UBVRI field photometry
  48. GRB 000301C: OT confirmed
  49. GRB000301c optical observations
  50. GRB000301C, optical observations
  51. GRB000301C
  52. GRB 000301C : Optical Candidate
  53. GRB000301C: RXTE/ASM and IPN localizations
  54. GRB000226 [IPN Position]
  55. HST Observations of GRB 990712
  56. GRB 000214 near-IR observations
  57. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  58. GRB000210, Radio Observations
  59. GRB 000115, BVRI field photometry
  60. GRB000214: BeppoSAX GRBM and WFC Detection
  61. Optical observations of GRB000210
  62. GRB000210 X-ray afterglow
  63. GRB000214: X-ray afterglow candidate
  64. GRB000214 refined BeppoSAX-WFC position
  65. GRB 000210: BATSE Observations
  66. Optical observations of the Chandra X-ray source for GRB000210
  67. GRB000210, Radio Observations
  68. IPN triangulation of GRB000210
  69. GRB000210: possible afterglow detection with BeppoSAX NFI
  70. GRB000201, Radio Observations
  71. GRB000210: BeppoSAX GRBM and WFC Detection
  72. SAX_WFC_GRB_NOTICE
  73. SAX_WFC_GRB_NOTICE
  74. GRB000201 Optical Observations
  75. GRB 000201: TAROT optical observations
  76. GRB 991208, radio observations
  77. BATSE+IPN location of GRB000131
  78. IPN localization of GRB000131
  79. GRB 000126, optical observations
  80. BATSE Observations of GRB000115
  81. Second RXTE Observation of GRB 000115
  82. GRB991216, UBVRIJHK field photometry
  83. GCN resumes full operations
  84. GRB 991216 VLBA Observations
  85. GRB 991216: J band spectrophotometry
  86. GRB 991216: Detection of the Host and/or Absorber Galaxy
  87. IPN localization of GRB991226
  88. GRB 991216 RXTE ASM Observations
  89. GRB 991216: Updated BATSE parameters
  90. GRB 991217 (SAX J2303.2+0015) Optical observations
  91. Chandra observation of the X-ray afterglow of GRB991216
  92. GRB 991216, optical observations
  93. GRB 991216 Optical spectroscopy/imaging
  94. SAX J2303.2+0015 Optical observations
  95. IR observations of GRB991216
  96. GRB 991217 (SAX J2303.2+0015) Optical observations
  97. GRB991216 Optical and infrared observations of Beethoven Burst
  98. GRB 991216 Radio Observations
  99. GRB 991208 Keck Spectroscopy
  100. GRB 991208 Infrared Detection

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