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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"

24846 results found.

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

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