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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"

21767 results found.

  1. GRB 990705, R-band observations
  2. Infrared and Optical Observations of GRB990705
  3. GRB 990705, radio observations
  4. GRB990704: SAX-NFI results summary
  5. GRB990704 radio and optical observations
  6. GRB990704
  7. GRB990704, optical observations
  8. GRB 990627, radio observations
  9. Late-time HST/STIS Observation of GRB 990123
  10. Optical Observations of GRB 990506
  11. GRB990527 Optical Observations
  12. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  13. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  14. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  15. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  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. GRB 990510: optical linear polarization
  23. GRB 990510: optical observations
  24. GRB990510, VI observations
  25. GRB 990510: BATSE Observations
  26. GRB 990510: BeppoSAX/GRBM observations
  27. GRB 990510 optical observations
  28. GRB 990506 Radio Observations
  29. GRB 990123, optical monitoring
  30. GRB 990506, optical observations
  31. GRB 990506, Optical Observations
  32. GRB 990506 optical observations
  33. GRB 990506, optical observations
  34. GRB 990506, optical observations from +1 to +3 hours
  35. GRB 990506, optical observations
  36. GRB990506 observation plan
  37. GRB981220 VLBA observations
  38. GRB 990316 Optical Observations
  39. GRB 990316 optical observations
  40. GRB990316: simultaneous optical observation
  41. GRB990316 - Optical null results
  42. GRB 990123, Field Photometry
  43. GRB 990217 Optical Observations
  44. GRB 990217, radio observations
  45. BATSE Flight Anomaly
  46. GRB990123 observations
  47. GRB990123, Optical Observation
  48. GRB 990123: Discovery of the Probable Host Galaxy
  49. GRB 990123: Reduced HST Images
  50. GRB19990123 observations
  51. GRB 990123: BVRI standards in the field
  52. GRB981220, field photometry
  53. GRB990123, Optical observation
  54. GRB990123, 15-GHz limits
  55. GRB 990123: New Constraints on Possible Foreground Galaxies
  56. GRB990123 Optical Observations
  57. GRB990123, Probability of gravitational lensing
  58. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  59. GRB990123, Preliminary Lens Search Results
  60. GRB990123, Optical BVRI Observations
  61. GRB 990123: near-infrared observations.
  62. GRB990123, OSSE observations
  63. GRB990123: NIR Observation
  64. "GRB 990123: New BV 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. GRB 990123 r-band photometry
  71. GRB 990123 Optical Follow-up
  72. GRB990123, early optical counterpart detection
  73. GRB 990123, Radio observations
  74. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  75. Possible identification of SN1999E with GRB980910
  76. Optical Observations of GRB 981220
  77. GRB 981226: radio variable
  78. GRB 981226 Optical Observations
  79. GRB981226 BeppoSAX follow up
  80. GRB 981226
  81. GRB 981226 optical observations
  82. GRB981220 B, R and I band observations
  83. GRB 981220:Optical Observations
  84. GRB 981226 optical observations
  85. GRB 981220, radio observations
  86. GRB 981220: BeppoSAX/GRBM results
  87. GRB981220 Optical Observations
  88. GRB 981220
  89. GRB 980326/Host Galaxy
  90. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  91. BeppoSAX NFI Observation of GRB980425
  92. GRB980329 R,I flux calibration and R,I,K upper limits
  93. GRB980425 Optical Follow-up
  94. GRB980425: X-ray revised positions
  95. GRB980703 Very Long Baseline Interferometry
  96. GRB970508 optical observations
  97. GRB980519, Optical Observations
  98. GRB980703 - BeppoSAX/GRBM detection
  99. GRB980703 optical photometry
  100. GRB 980703: BATSE Observations

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