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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"

20558 results found.

  1. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  2. radio observations of X-ray/GRB transient field
  3. Optical report on X-ray/GRB transient
  4. radio detection of X-ray/GRB transient
  5. BeppoSAX: A new fast X-ray transient
  6. GRB 990510: optical observations
  7. GRB990510: photometric and spectroscopic observations with the VLT
  8. GRB 990510: optical observations
  9. GRB990510, VI observations
  10. GRB 990506 R band observations
  11. GRB990510: X-ray afterglow
  12. GRB 990510: optical observation
  13. GRB 990510: Broad Band Break
  14. GRB 990510: BATSE Observations
  15. GRB 990510 Optical Observations
  16. GRB 990510, BVI photometry
  17. GRB 990510 optical observations
  18. GRB 990510: BeppoSAX/GRBM observations
  19. GRB990510 optical observations
  20. GRB990510
  21. GRB 990510 optical observations
  22. GRB 990510 optical observations
  23. GRB 990510 optical observations
  24. GRB 990506 Radio Observations
  25. GRB 990123, optical monitoring
  26. GRB 990506: BATSE Observations
  27. GRB 990506, optical observations
  28. GRB 990506, Optical Observations
  29. GRB 990506 optical observations
  30. GRB 990506 optical observations
  31. GRB 990506, optical observations
  32. GRB990506 observation plan
  33. GRB 990506: Limits on the possible optical transient
  34. GRB 990506, optical observations from +1 to +3 hours
  35. GRB 990506, optical observations
  36. GRB990506 Optical observations
  37. GRB 970228: Redshift and properties of the host galaxy
  38. GRB981220 VLBA observations
  39. GRB980425 Optical observations of exponential decline at late time
  40. GRB 990316 Optical Observations
  41. GRB 990316, Radio observations
  42. GRB 990316, Optical observations
  43. GRB990316, Optical observations
  44. GRB 990316 optical observations
  45. GRB990316: simultaneous optical observation
  46. GRB990308 not a new SGR
  47. GRB990308 (Trig. 7457), optical observations
  48. GRB990308, Possible new SGR~0209+70
  49. GRB 981220, radio observations
  50. GRB 990217 Optical Observations
  51. GRB 990217, radio observations
  52. Optical Observations of GRB990217
  53. GRB990123 observations
  54. GRB990123, Optical Observation
  55. GRB 990123: Discovery of the Probable Host Galaxy
  56. GRB 990123: Reduced HST Images
  57. For Immediate Posting to GCN - HST Data GRB 990123 Available
  58. GRB19990123 observations
  59. GRB 990123: Updated Keck Spectroscopy Results
  60. GRB981220, field photometry
  61. GRB 990123 NOT Spectrum Update
  62. GRB990123, Optical observation
  63. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  64. GRB 990123: Publicly available reduced HST images
  65. GRB990123, Upcoming HST Service Observations
  66. GRB990123, 15-GHz limits
  67. GRB 990123: New Constraints on Possible Foreground Galaxies
  68. GRB990123 Optical Observations
  69. GRB990123, Probability of gravitational lensing
  70. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  71. GRB 990123: Continued Radio Observations
  72. GRB990123, Preliminary Lens Search Results
  73. On the Lensing Interpretation of GRB 990123
  74. Search for Potential Images of GRB 990123
  75. GRB990123, Optical BVRI Observations
  76. GRB 990123: near-infrared observations.
  77. GRB990123, OSSE observations
  78. GRB990123: NIR Observation
  79. "GRB 990123: New BV Observations"
  80. GRB 990123 Optical Follow-Up
  81. GRB 990123; Addendum to GCN 223
  82. GRB 990123: BATSE Observations
  83. GRB 990123 Keck Spectrum update
  84. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  85. GRB990123 Optical Observations
  86. GRB 990123 Spectroscopic Redshifts
  87. GRB 990123: New Optical Observations, Decay Measure
  88. GRB 990123 Optical Follow-Up
  89. GRB 990123: Possible Gravitationally Lensed Burst?
  90. GRB990123, optical observation
  91. GRB 990123 optical observations
  92. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  93. GRB 990123 radio observations
  94. GRB 990123, new radio source
  95. GRB990123 optical observations
  96. GRB990123, Optical observation
  97. GRB 990123 Optical Follow-up
  98. GRB 990123: Bright New Source, Possible Optical Transient
  99. GRB 990123, Radio observations
  100. SN 1999E & GRB 980919

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