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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"

28054 results found.

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

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