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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"

23399 results found.

  1. GRB 990705, R-band observations
  2. Updated IPN localization of GRB990705
  3. IPN localization of GRB990704
  4. IPN localization of GRB990705
  5. Infrared and Optical Observations of GRB990705
  6. GRB 990705, radio observations
  7. GRB990704: SAX-NFI results summary
  8. GRB990704 radio and optical observations
  9. GRB990704
  10. GRB990704, optical observations
  11. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  12. Optical Observations of GRB990627
  13. GRB 990627, radio observations
  14. GRB990627: BeppoSAX-WFC final location
  15. Late-time HST/STIS Observation of GRB 990123
  16. Optical Observations of GRB 990506
  17. GRB990527 Optical Observations
  18. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  19. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  20. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  21. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  22. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  23. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  24. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  25. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  26. radio observations of X-ray/GRB transient field
  27. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  28. Optical report on X-ray/GRB transient
  29. radio detection of X-ray/GRB transient
  30. BeppoSAX: A new fast X-ray transient
  31. GRB990510: photometric and spectroscopic observations with the VLT
  32. GRB 990510: optical linear polarization
  33. GRB 990510: optical observations
  34. GRB990510, VI observations
  35. GRB 990506 R band observations
  36. GRB990510: X-ray afterglow
  37. GRB 990510: Broad Band Break
  38. GRB990510 optical observations
  39. GRB 990510 optical observations
  40. IPN localization of GRB990510
  41. GRB 990506 Radio Observations
  42. GRB 990123, optical monitoring
  43. GRB 990506, optical observations
  44. GRB 990510: Final BeppoSAX-WFC Coordinates
  45. GRB 990506, Optical Observations
  46. GRB 990506 optical observations
  47. GRB 990506, optical observations
  48. GRB 990506, optical observations from +1 to +3 hours
  49. GRB 990506, optical observations
  50. GRB990506 observation plan
  51. IPN localization for GRB990506
  52. GRB 970228: Redshift and properties of the host galaxy
  53. GRB 990316 Optical Observations
  54. GRB 990316, Radio observations
  55. GRB 990316 optical observations
  56. GRB990316: simultaneous optical observation
  57. ASM/IPN error box for GRB 990308 (BATSE #7457)
  58. GRB990308 (Trig. 7457), optical observations
  59. GRB981220, IPN localization
  60. GRB 990123, Field Photometry
  61. GRB 990217 Optical Observations
  62. GRB 990217, radio observations
  63. BATSE Flight Anomaly
  64. GRB990123 observations
  65. GRB990217, WFC position
  66. GRB990123, Optical Observation
  67. GRB 990123: Discovery of the Probable Host Galaxy
  68. GRB19990123 observations
  69. GRB 990123: BVRI standards in the field
  70. GRB981220, field photometry
  71. GRB990123, Optical observation
  72. GRB990123, Upcoming HST Service Observations
  73. GRB990123, 15-GHz limits
  74. GRB 990123: New Constraints on Possible Foreground Galaxies
  75. GRB990123 Optical Observations
  76. GRB990123, Probability of gravitational lensing
  77. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  78. GRB990123, Preliminary Lens Search Results
  79. On the Lensing Interpretation of GRB 990123
  80. Search for Potential Images of GRB 990123
  81. GRB990123, Optical BVRI Observations
  82. GRB 990123: near-infrared observations.
  83. GRB990123, OSSE observations
  84. GRB990123: NIR Observation
  85. "GRB 990123: New BV Observations"
  86. GRB990123 IPN annulus
  87. GRB 990123 Spectroscopic Redshifts
  88. GRB 990123: New Optical Observations, Decay Measure
  89. GRB 990123 Optical Follow-Up
  90. GRB 990123: Possible Gravitationally Lensed Burst?
  91. GRB990123, optical observation
  92. GRB 990123 optical observations
  93. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  94. GRB 990123 radio observations
  95. GRB 990123: Optical Decay Slope
  96. GRB 990123 r-band photometry
  97. GRB 990123 Optical Follow-up
  98. GRB990123, early optical counterpart detection
  99. GRB990123 Optical Observation
  100. Possible identification of SN1999E with GRB980910

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