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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"

26301 results found.

  1. GRB000418, near-infrared observations
  2. Correction to IPN error box for GRB000419
  3. IPN error box for GRB000418
  4. GRB000419 [IPN Position]
  5. 1SAXJ1715.0-7134 refined position
  6. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  7. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  8. Budget cuts in BeppoSAX operations: impact on GRB observations
  9. GRB000301c results
  10. GRB000408: Optical CCD Observations from MIRO
  11. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  12. GRB000408 [IPN Position]
  13. GRB000326 Optical Observations
  14. GRB 000326: Optical Observations
  15. GRB 000307 optical observations
  16. GRB000323 [IPN Position]
  17. GRB000313, Radio observations
  18. GRB000301C - B and R photometry
  19. GRB000301C - R photometry
  20. GRB 000307, Optical Observations
  21. GRB 000301C: Optical Spectrum and Redshift
  22. GRB 000301C: Optical Spectrum and Redshift
  23. GRB 000301C: A Precise Redshift Determination
  24. GRB 000301C, Optical Observation
  25. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  26. GRB 000301C: HST/STIS CCD Imaging of the field
  27. IPN error box for GRB000307
  28. GRB 000301c: K' observations
  29. GRB000301C, optical R-band observations
  30. GRB000301c - R photometry and nearby faint source confirmation
  31. GRB 000301C: K' Observations
  32. Optical observations of GRB000301c
  33. GRB000301C, Radio observations
  34. GRB000301C, Radio observations
  35. GRB000301C, near-infrared observations (JHK' imaging)
  36. GRB 000301c near-IR observations
  37. GRB 000301C, Optical Color
  38. GRB000301C 250 GHz detection
  39. GRB 000301C R-band observation
  40. GRB 000301C, Optical Observation
  41. GRB000301C, near-infrared observations (JHK' photometry)
  42. GRB 000301C: OT confirmed
  43. GRB 000301A, Radio Observations
  44. GRB000301C, optical observations
  45. GRB000301c, near-infrared observations
  46. GRB000301C
  47. GRB000301C: RXTE/ASM and IPN localizations
  48. HST Observations of GRB 990712
  49. GRB 000214 near-IR observations
  50. GRB 000115 Optical observations
  51. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  52. GRB000210, Radio Observations
  53. IPN annulus for GRB000214
  54. GRB000210 X-ray afterglow
  55. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  56. GRB 000210: BATSE Observations
  57. Correction to Chandra Position of GRB000210 afterglow
  58. Optical observations of the Chandra X-ray source for GRB000210
  59. GRB000210, Radio Observations
  60. Optical candidate for GRB000210
  61. IPN triangulation of GRB000210
  62. GRB000201, Radio Observations
  63. Optical observations of GRB000131
  64. GRB000201 Optical Observations
  65. GRB 000131 Optical Observations
  66. BATSE+IPN location of GRB000131
  67. IPN localization of GRB000131
  68. GRB 000126, optical observations
  69. GRB000126, optical observations
  70. BATSE location of GRB000126
  71. BATSE Observations of GRB000115
  72. GRB991216, UBVRIJHK field photometry
  73. GRB991216 late optical observation
  74. Single IPN error box for GRB991229
  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. Lowell/Perkins observation of GRB 991216
  80. GRB 991217 (SAX J2303.2+0015) Optical observations
  81. GRB 991216 Optical spectroscopy/imaging
  82. GRB991216 Optical and IR observations
  83. SAX J2303.2+0015 Optical observations
  84. IR observations of GRB991216
  85. GRB991216 radio observations
  86. GRB 991217 (SAX J2303.2+0015) Optical observations
  87. GRB991216 radio observations
  88. GRB991216, optical observations
  89. GRB991216 Optical and infrared observations of Beethoven Burst
  90. Refined IPN localization of GRB991216
  91. GRB 991216 Radio Observations
  92. GRB 991208 Keck Spectroscopy
  93. GRB991216
  94. GRB 991216--Summary of RXTE Observations
  95. GRB 991216 Optical Observations
  96. GRB 991216, optical observations
  97. GRB 991216, Optical Transient
  98. GRB 991216, Optical Afterglow
  99. GRB991216 ('Beethoven Burst') B, R, and K Observations
  100. GRB 991216: Comparison with DPOSS images

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