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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"

20964 results found.

  1. GRB990806 UBVRIJHK observations
  2. GRB 990712 Optical Observations
  3. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  4. GRB 990712
  5. Late-time HST/STIS Observations of GRB 990510
  6. GRB 990705, R-band observations
  7. Infrared and Optical Observations of GRB990705
  8. GRB 990705, radio observations
  9. GRB990704 radio and optical observations
  10. GRB 990704 X-ray Observations
  11. GRB 990704 Optical Observations
  12. GRB 990704, optical observations
  13. GRB990704
  14. GRB990704, optical observations
  15. Identification of a possible optical counterpart for GRB990704
  16. GRB990704
  17. Optical Observations of GRB990627
  18. GRB 990627, radio observations
  19. Late-time HST/STIS Observation of GRB 990123
  20. GRB 990506 - Optical Observations
  21. Optical Observations of GRB 990506
  22. GRB 990506 Radio Transient
  23. GRB990527 Optical Observations
  24. Late Afterglows of GRBs 990510, 990123
  25. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  26. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  27. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  28. radio observations of X-ray/GRB transient field
  29. radio detection of X-ray/GRB transient
  30. BeppoSAX: A new fast X-ray transient
  31. GRB 990510: optical observations
  32. GRB990510: photometric and spectroscopic observations with the VLT
  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. GRB 990510: BATSE Observations
  39. GRB 990510 Optical Observations
  40. GRB 990510, BVI photometry
  41. GRB 990510 optical observations
  42. GRB 990510: BeppoSAX/GRBM observations
  43. GRB990510 optical observations
  44. GRB990510
  45. GRB 990510 optical observations
  46. GRB 990510 optical observations
  47. GRB 990510 optical observations
  48. GRB 990506 Radio Observations
  49. GRB 990123, optical monitoring
  50. GRB 990506: BATSE Observations
  51. GRB 990506, optical observations
  52. GRB 990506, Optical Observations
  53. GRB 990506 optical observations
  54. GRB 990506 optical observations
  55. GRB 990506, optical observations
  56. GRB990506 observation plan
  57. GRB 990506: Limits on the possible optical transient
  58. GRB 990506, optical observations from +1 to +3 hours
  59. GRB 990506, optical observations
  60. GRB990506 Optical observations
  61. GRB981220 VLBA observations
  62. GRB980425 Optical observations of exponential decline at late time
  63. GRB 990316 Optical Observations
  64. GRB 990316, Radio observations
  65. GRB 990316, Optical observations
  66. GRB990316, Optical observations
  67. GRB 990316 optical observations
  68. GRB990316: simultaneous optical observation
  69. GRB990308 not a new SGR
  70. GRB990308 (Trig. 7457), optical observations
  71. GRB990308, Possible new SGR~0209+70
  72. GRB 981220, radio observations
  73. GRB 990217 Optical Observations
  74. GRB 990217, radio observations
  75. Optical Observations of GRB990217
  76. GRB990123 observations
  77. GRB990123, Optical Observation
  78. GRB 990123: Reduced HST Images
  79. For Immediate Posting to GCN - HST Data GRB 990123 Available
  80. GRB19990123 observations
  81. GRB981220, field photometry
  82. GRB 990123 NOT Spectrum Update
  83. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  84. GRB 990123: Publicly available reduced HST images
  85. GRB990123, Upcoming HST Service Observations
  86. GRB990123, 15-GHz limits
  87. GRB 990123: New Constraints on Possible Foreground Galaxies
  88. GRB990123 Optical Observations
  89. GRB990123, Probability of gravitational lensing
  90. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  91. GRB 990123: Continued Radio Observations
  92. GRB990123, Preliminary Lens Search Results
  93. GRB990123, Optical BVRI Observations
  94. GRB 990123: near-infrared observations.
  95. GRB990123, OSSE observations
  96. GRB990123: NIR Observation
  97. "GRB 990123: New BV Observations"
  98. GRB 990123 Optical Follow-Up
  99. GRB 990123; Addendum to GCN 223
  100. GRB 990123: BATSE Observations

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