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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"

28044 results found.

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

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