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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"

24847 results found.

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

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