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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"

25891 results found.

  1. GRB 991216 RXTE ASM Observations
  2. Chandra observation of the X-ray afterglow of GRB991216
  3. GRB991216 Optical and IR observations
  4. GRB991216 radio observations
  5. GRB991216 Optical and infrared observations of Beethoven Burst
  6. GRB 991216 Radio Observations
  7. GRB 991208 Infrared Detection
  8. GRB 991216--Summary of RXTE Observations
  9. GRB 991216, Optical Afterglow
  10. GRB991216 Optical Observations
  11. R-band Observations of GRB991208 at TNG
  12. GRB 991208 Keck Spectroscopy
  13. GRB991208 - millimeter detection
  14. GRB 991208, Optical Observation
  15. GRB991208, optical observations
  16. GRB 991208 - OVRO detection
  17. GRB 991208 Optical Decay
  18. GRB 991208 optical observations
  19. GRB 991208 optical observations
  20. GRB 991208: Radio Observations
  21. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  22. GRB 991014 - BeppoSAX NFI observations
  23. GRB 991014, Optical Observations
  24. GRB 990915 optical observations
  25. GRB990907: BeppoSAX follow up and X-ray afterglow
  26. GRB 990712 Late Optical Decay and Host Galaxy
  27. GRB 990712, Optical Observation
  28. GRB990806 BeppoSAX follow up
  29. GRB990806: possible X-ray afterglow, BeppoSAX
  30. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  31. GRB 990705, radio observations
  32. GRB990704: SAX-NFI results summary
  33. BeppoSAX GRB990705: possible X-ray afterglow
  34. GRB990704: possible X-ray afterglow
  35. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  36. GRB 990627, radio observations
  37. GRB 990506 Radio Transient
  38. Late Afterglows of GRBs 990510, 990123
  39. GRB990510: X-ray afterglow
  40. GRB 990510: Broad Band Break
  41. GRB990510: NFI X-ray source
  42. GRB 990506: BATSE Observations
  43. IPN localization for GRB990506
  44. GRB981220 VLBA observations
  45. GRB990316: simultaneous optical observation
  46. GRB 981220, radio observations
  47. GRB990123, Optical Observation
  48. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  49. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  50. GRB 990123: Continued Radio Observations
  51. GRB990123, Preliminary Lens Search Results
  52. GRB990123, ASCA X-ray observation of afterglow
  53. GRB 990123 optical observations
  54. GRB 990123, new radio source
  55. GRB 990123: Optical Decay Slope
  56. GRB 990123 r-band photometry
  57. GRB990123, BeppoSAX-NFI X-ray afterglow detection
  58. Optical Observations of GRB 981220
  59. GRB981220
  60. GRB 981220 Optical observations
  61. GRB 981226 Optical Observations
  62. GRB981226 Optical Observations
  63. GRB 981226
  64. GRB981220 B, R and I band observations
  65. GRB 981220
  66. GRB 981220, radio observations
  67. GRB980425 Optical Follow-up
  68. GRB980703 Very Long Baseline Interferometry
  69. GRB980703: Radio transient
  70. GRB 980703: Spectrum of the proposed optical counterpart
  71. RXTE Observation of GRB 980706
  72. GRB980613 Optical Observations
  73. GRB980703 optical followup
  74. GRB 980613 Optical Observations
  75. GRB980613 Optical Observations
  76. GRB980613 BeppoSAX-NFI follow up
  77. GRB 980519
  78. GRB980515, BeppoSAX IAUC to be submitted
  79. SAX J0840.7+2248 Optical Observations
  80. GRB 980329 ROSAT observation
  81. GRB980326 X-ray Observations
  82. GRB980329, Fading IR counterpart to radio source
  83. GRB980329 sub-millimeter observations
  84. GRB980329 near-IR observations
  85. GRB980329 optical observations
  86. GRB980329 VLA observations
  87. GRB980329 optical observations
  88. Near-IR follow-up on GRB 971227
  89. GRB971227: Plaskett R-band observations
  90. GRB 971227: Optical clarifications
  91. GRB971227: Further CAHA R-band images

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