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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"

26348 results found.

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

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