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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"

24952 results found.

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

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