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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"

20948 results found.

  1. Optical Observations of GRB990627
  2. GRB 990627, radio observations
  3. Late-time HST/STIS Observation of GRB 990123
  4. GRB 990506 - Optical Observations
  5. Optical Observations of GRB 990506
  6. GRB 990506 Radio Transient
  7. GRB990527 Optical Observations
  8. Late Afterglows of GRBs 990510, 990123
  9. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  10. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  11. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  12. radio observations of X-ray/GRB transient field
  13. radio detection of X-ray/GRB transient
  14. BeppoSAX: A new fast X-ray transient
  15. GRB 990510: optical observations
  16. GRB990510: photometric and spectroscopic observations with the VLT
  17. GRB 990510: optical observations
  18. GRB990510, VI observations
  19. GRB 990506 R band observations
  20. GRB990510: X-ray afterglow
  21. GRB 990510: Broad Band Break
  22. GRB 990510: BATSE Observations
  23. GRB 990510 Optical Observations
  24. GRB 990510, BVI photometry
  25. GRB 990510 optical observations
  26. GRB 990510: BeppoSAX/GRBM observations
  27. GRB990510 optical observations
  28. GRB990510
  29. GRB 990510 optical observations
  30. GRB 990510 optical observations
  31. GRB 990510 optical observations
  32. GRB 990506 Radio Observations
  33. GRB 990123, optical monitoring
  34. GRB 990506: BATSE Observations
  35. GRB 990506, optical observations
  36. GRB 990506, Optical Observations
  37. GRB 990506 optical observations
  38. GRB 990506 optical observations
  39. GRB 990506, optical observations
  40. GRB990506 observation plan
  41. GRB 990506: Limits on the possible optical transient
  42. GRB 990506, optical observations from +1 to +3 hours
  43. GRB 990506, optical observations
  44. GRB990506 Optical observations
  45. GRB981220 VLBA observations
  46. GRB980425 Optical observations of exponential decline at late time
  47. GRB 990316 Optical Observations
  48. GRB 990316, Radio observations
  49. GRB 990316, Optical observations
  50. GRB990316, Optical observations
  51. GRB 990316 optical observations
  52. GRB990316: simultaneous optical observation
  53. GRB990308 not a new SGR
  54. GRB990308 (Trig. 7457), optical observations
  55. GRB990308, Possible new SGR~0209+70
  56. GRB 981220, radio observations
  57. GRB 990217 Optical Observations
  58. GRB 990217, radio observations
  59. Optical Observations of GRB990217
  60. GRB990123 observations
  61. GRB990123, Optical Observation
  62. GRB 990123: Reduced HST Images
  63. For Immediate Posting to GCN - HST Data GRB 990123 Available
  64. GRB19990123 observations
  65. GRB981220, field photometry
  66. GRB 990123 NOT Spectrum Update
  67. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  68. GRB 990123: Publicly available reduced HST images
  69. GRB990123, Upcoming HST Service Observations
  70. GRB990123, 15-GHz limits
  71. GRB 990123: New Constraints on Possible Foreground Galaxies
  72. GRB990123 Optical Observations
  73. GRB990123, Probability of gravitational lensing
  74. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  75. GRB 990123: Continued Radio Observations
  76. GRB990123, Preliminary Lens Search Results
  77. GRB990123, Optical BVRI Observations
  78. GRB 990123: near-infrared observations.
  79. GRB990123, OSSE observations
  80. GRB990123: NIR Observation
  81. "GRB 990123: New BV Observations"
  82. GRB 990123 Optical Follow-Up
  83. GRB 990123; Addendum to GCN 223
  84. GRB 990123: BATSE Observations
  85. GRB990123 Optical Observations
  86. GRB 990123 Spectroscopic Redshifts
  87. GRB 990123: New Optical Observations, Decay Measure
  88. GRB 990123 optical observations
  89. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  90. GRB 990123 radio observations
  91. GRB 990123, new radio source
  92. GRB990123 optical observations
  93. GRB 990123: Optical Decay Slope
  94. GRB 990123, Radio observations
  95. SN 1999E & GRB 980919
  96. Possible identification of SN1999E with GRB980910
  97. Optical Observations of GRB 981220
  98. GRB981220
  99. GRB981220, Correction to GCN 179
  100. GRB981220, Optical Observations

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