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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.

Lucene Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

23213 results found.

  1. GRB990704: SAX-NFI results summary
  2. GRB990704 radio and optical observations
  3. BeppoSAX GRB990705: possible X-ray afterglow
  4. GRB 990704 X-ray Observations
  5. GRB990704
  6. GRB990704, optical observations
  7. Late-time HST/STIS Observation of GRB 990123
  8. Optical Observations of GRB 990506
  9. GRB990527 Optical Observations
  10. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  11. IPN error box for GRB990527
  12. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  13. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  14. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  15. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  16. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  17. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  18. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  19. radio observations of X-ray/GRB transient field
  20. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  21. Optical report on X-ray/GRB transient
  22. BeppoSAX: A new fast X-ray transient
  23. GRB990510: photometric and spectroscopic observations with the VLT
  24. GRB 990510: optical linear polarization
  25. GRB 990510: optical observations
  26. GRB990510, VI observations
  27. GRB 990510: Broad Band Break
  28. GRB 990510: BATSE Observations
  29. GRB990510: optical observation
  30. GRB 990510: BeppoSAX/GRBM observations
  31. GRB990510 optical observations
  32. GRB 990510 optical observations
  33. GRB 990510 optical observations
  34. GRB 990506 Radio Observations
  35. GRB 990123, optical monitoring
  36. GRB 990506: BATSE Observations
  37. GRB 990506, optical observations
  38. GRB 990506, Optical Observations
  39. GRB 990506 optical observations
  40. GRB 990506, optical observations
  41. GRB 990506, optical observations from +1 to +3 hours
  42. GRB 990506, optical observations
  43. GRB990506 observation plan
  44. GRB 990316 Optical Observations
  45. GRB 990316, Radio observations
  46. GRB 990316, Optical observations
  47. GRB990316, Optical observations
  48. GRB 990316 optical observations
  49. GRB990316: simultaneous optical observation
  50. GRB990316 - Optical null results
  51. ASM/IPN error box for GRB 990308 (BATSE #7457)
  52. GRB 990308a and GRB 990308b
  53. GRB990308 (Trig. 7457), optical observations
  54. GRB990308, Possible new SGR~0209+70
  55. GRB 990123, Field Photometry
  56. GRB 990217 Optical Observations
  57. BATSE Flight Anomaly
  58. GRB990217: BeppoSAX/GRBM data
  59. GRB990123 observations
  60. GRB990217 Optical observation
  61. GRB990123, Optical Observation
  62. GRB 990123: Discovery of the Probable Host Galaxy
  63. GRB19990123 observations
  64. GRB 990123: BVRI standards in the field
  65. GRB981220, field photometry
  66. GRB990123, Optical observation
  67. GRB990123, 15-GHz limits
  68. GRB 990123: New Constraints on Possible Foreground Galaxies
  69. GRB990123 Optical Observations
  70. GRB990123, Probability of gravitational lensing
  71. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  72. GRB 990123: Continued Radio Observations
  73. GRB990123, Preliminary Lens Search Results
  74. On the Lensing Interpretation of GRB 990123
  75. Search for Potential Images of GRB 990123
  76. GRB990123, Optical BVRI Observations
  77. GRB 990123: near-infrared observations.
  78. GRB990123, OSSE observations
  79. GRB990123: NIR Observation
  80. GRB990123, ASCA X-ray observation of afterglow
  81. "GRB 990123: New BV Observations"
  82. GRB 990123 Optical Follow-Up
  83. GRB 990123: BATSE Observations
  84. GRB990123 IPN annulus
  85. GRB 990123 Spectroscopic Redshifts
  86. GRB 990123: New Optical Observations, Decay Measure
  87. GRB 990123 Optical Follow-Up
  88. GRB 990123: Possible Gravitationally Lensed Burst?
  89. GRB990123, optical observation
  90. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  91. GRB 990123, new radio source
  92. GRB990123, Optical observation
  93. GRB 990123 r-band photometry
  94. GRB 990123 Optical Follow-up
  95. GRB990123 Optical Observation
  96. GRB990123, refined SAX-WFC position
  97. Possible identification of SN1999E with GRB980910
  98. Optical Observations of GRB 981220
  99. GRB 981226: radio variable
  100. GRB981220

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