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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.

Lucene Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

19138 results found.

  1. GRB 990510 optical observations
  2. GRB 990510 optical observations
  3. GRB 990510 optical observations
  4. GRB 990506 Radio Observations
  5. GRB 990123, optical monitoring
  6. GRB 990506: BATSE Observations
  7. GRB 990506, optical observations
  8. GRB 990506, Optical Observations
  9. GRB 990506 optical observations
  10. GRB 990506 optical observations
  11. GRB 990506, optical observations
  12. GRB990506 observation plan
  13. GRB 990506: Limits on the possible optical transient
  14. GRB 990506, optical observations from +1 to +3 hours
  15. GRB 990506, optical observations
  16. GRB990506 Optical observations
  17. GRB 970228: Redshift and properties of the host galaxy
  18. GRB981220 VLBA observations
  19. GRB980425 Optical observations of exponential decline at late time
  20. GRB 990316 Optical Observations
  21. GRB 990316, Radio observations
  22. GRB 990316, Optical observations
  23. GRB990316, Optical observations
  24. GRB 990316 optical observations
  25. GRB990316: simultaneous optical observation
  26. GRB990308 not a new SGR
  27. GRB990308 (Trig. 7457), optical observations
  28. GRB990308, Possible new SGR~0209+70
  29. GRB 981220, radio observations
  30. GRB 990217 Optical Observations
  31. GRB 990217, radio observations
  32. Optical Observations of GRB990217
  33. GRB990123 observations
  34. GRB990123, Optical Observation
  35. GRB 990123: Discovery of the Probable Host Galaxy
  36. GRB 990123: Reduced HST Images
  37. For Immediate Posting to GCN - HST Data GRB 990123 Available
  38. GRB19990123 observations
  39. GRB 990123: Updated Keck Spectroscopy Results
  40. GRB981220, field photometry
  41. GRB 990123 NOT Spectrum Update
  42. GRB990123, Optical observation
  43. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  44. GRB 990123: Publicly available reduced HST images
  45. GRB990123, Upcoming HST Service Observations
  46. GRB990123, 15-GHz limits
  47. GRB 990123: New Constraints on Possible Foreground Galaxies
  48. GRB990123 Optical Observations
  49. GRB990123, Probability of gravitational lensing
  50. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  51. GRB 990123: Continued Radio Observations
  52. GRB990123, Preliminary Lens Search Results
  53. On the Lensing Interpretation of GRB 990123
  54. Search for Potential Images of GRB 990123
  55. GRB990123, Optical BVRI Observations
  56. GRB 990123: near-infrared observations.
  57. GRB990123, OSSE observations
  58. GRB990123: NIR Observation
  59. "GRB 990123: New BV Observations"
  60. GRB 990123 Optical Follow-Up
  61. GRB 990123; Addendum to GCN 223
  62. GRB 990123: BATSE Observations
  63. GRB 990123 Keck Spectrum update
  64. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  65. GRB990123 Optical Observations
  66. GRB 990123 Spectroscopic Redshifts
  67. GRB 990123: New Optical Observations, Decay Measure
  68. GRB 990123 Optical Follow-Up
  69. GRB 990123: Possible Gravitationally Lensed Burst?
  70. GRB990123, optical observation
  71. GRB 990123 optical observations
  72. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  73. GRB 990123 radio observations
  74. GRB 990123, new radio source
  75. GRB990123 optical observations
  76. GRB990123, Optical observation
  77. GRB 990123 Optical Follow-up
  78. GRB 990123: Bright New Source, Possible Optical Transient
  79. GRB 990123, Radio observations
  80. SN 1999E & GRB 980919
  81. Possible identification of SN1999E with GRB980910
  82. Optical Observations of GRB 981220
  83. GRB 981226: radio variable
  84. GRB981220
  85. GRB981220, Correction to GCN 179
  86. GRB981220, Optical Observations
  87. GRB 981220 Optical observations
  88. GRB 981226 Optical Observations
  89. GRB 980613: Spectroscopy of the host galaxy
  90. GRB981226, sub-millimeter observations
  91. GRB981220, sub-millimeter observations
  92. GRB 981220 and GRB 981226, optical observations
  93. GRB981226 Optical Observations
  94. GRB 981226 radio observations
  95. GRB 981226
  96. GRB 981226 optical observations
  97. radio observations of GRB 981226
  98. GRB981220 B, R and I band observations
  99. Optical Observations of GRB981226
  100. GRB 981220:Optical Observations

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