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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"

28083 results found.

  1. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  2. Optical report on X-ray/GRB transient
  3. radio detection of X-ray/GRB transient
  4. BeppoSAX: A new fast X-ray transient
  5. GRB 990510: optical observations
  6. GRB 990510: optical linear polarization
  7. GRB 990510: optical observations
  8. GRB990510: X-ray afterglow
  9. GRB 990510: Broad Band Break
  10. GRB 990510: BATSE Observations
  11. GRB 990510: BeppoSAX/GRBM observations
  12. GRB990510 optical observations
  13. GRB 990510 optical observations
  14. GRB 990506 Radio Observations
  15. GRB 990123, optical monitoring
  16. GRB 990506: BATSE Observations
  17. GRB 990506, optical observations
  18. GRB 990506, Optical Observations
  19. GRB 990506 optical observations
  20. GRB 990506, optical observations
  21. GRB 990506, armchair astronomy
  22. GRB 990506, optical observations from +1 to +3 hours
  23. GRB 990506, optical observations
  24. GRB990506 observation plan
  25. IPN localization for GRB990506
  26. GRB990323 PRECISE IPN POSITION
  27. GRB 990316 Optical Observations
  28. GRB 990316 optical observations
  29. GRB990316: simultaneous optical observation
  30. GRB990316 - Optical null results
  31. GRB990308 not a new SGR
  32. GRB 990308a and GRB 990308b
  33. GRB990308, Possible new SGR~0209+70
  34. GRB 990123, Field Photometry
  35. GRB 990217 Optical Observations
  36. BATSE Flight Anomaly
  37. GRB990217: BeppoSAX/GRBM data
  38. GRB990123 observations
  39. GRB990217 Optical observation
  40. GRB990123, Optical Observation
  41. GRB 990123: Discovery of the Probable Host Galaxy
  42. GRB 990123: Reduced HST Images
  43. GRB19990123 observations
  44. GRB 990123: BVRI standards in the field
  45. GRB981220, field photometry
  46. GRB990123, Optical observation
  47. GRB990123, 15-GHz limits
  48. GRB 990123: New Constraints on Possible Foreground Galaxies
  49. GRB990123 Optical Observations
  50. GRB990123, Probability of gravitational lensing
  51. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  52. GRB990123, Preliminary Lens Search Results
  53. On the Lensing Interpretation of GRB 990123
  54. Search for Potential Images of GRB 990123
  55. Search for Potential Images of GRB 990123
  56. GRB990123, Optical BVRI Observations
  57. GRB 990123: near-infrared observations.
  58. GRB990123, OSSE observations
  59. GRB990123: NIR Observation
  60. GRB990123, ASCA X-ray observation of afterglow
  61. "GRB 990123: New BV Observations"
  62. GRB 990123 Optical Follow-Up
  63. GRB 990123: BATSE Observations
  64. GRB990123 Optical Observations
  65. GRB 990123: New Optical Observations, Decay Measure
  66. GRB 990123 Optical Follow-Up
  67. GRB 990123: Possible Gravitationally Lensed Burst?
  68. GRB990123, optical observation
  69. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  70. GRB990123, Optical observation
  71. GRB 990123: Optical Decay Slope
  72. GRB 990123 r-band photometry
  73. GRB 990123 Optical Follow-up
  74. GRB990123, early optical counterpart detection
  75. GRB990123 Optical Observation
  76. Possible identification of SN1999E with GRB980910
  77. Optical Observations of GRB 981220
  78. GRB 981226: radio variable
  79. GRB981220
  80. GRB981220, Correction to GCN 179
  81. GRB 981220 Optical observations
  82. GRB 981226 Optical Observations
  83. GRB 981220 and GRB 981226, optical observations
  84. GRB981226 Optical Observations
  85. GRB981226 BeppoSAX follow up
  86. GRB 981226
  87. GRB 981226 optical observations
  88. GRB981220 B, R and I band observations
  89. Optical Observations of GRB981226
  90. GRB 981220:Optical Observations
  91. GRB 981226 optical observations
  92. GRB 981220
  93. GRB 981220, radio observations
  94. GRB981220 I-band Observations
  95. GRB 981220
  96. GRB 980326/Host Galaxy
  97. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  98. BeppoSAX NFI Observation of GRB980425
  99. GRB980329 R,I flux calibration and R,I,K upper limits
  100. GRB980425 Optical Follow-up

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