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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"

20364 results found.

  1. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  2. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  3. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  4. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  5. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  6. radio observations of X-ray/GRB transient field
  7. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  8. Optical report on X-ray/GRB transient
  9. GRB 990510: optical linear polarization
  10. GRB 990510: optical observations
  11. GRB990510, VI observations
  12. GRB 990510: Broad Band Break
  13. GRB 990510: BATSE Observations
  14. GRB 990510 optical observations
  15. IPN localization of GRB990510
  16. GRB 990506 Radio Observations
  17. GRB 990123, optical monitoring
  18. GRB 990506: BATSE Observations
  19. GRB 990506, optical observations
  20. GRB 990506, Optical Observations
  21. GRB 990506 optical observations
  22. GRB 990506, optical observations
  23. GRB 990506, optical observations from +1 to +3 hours
  24. GRB 990506, optical observations
  25. GRB990506 observation plan
  26. IPN localization for GRB990506
  27. GRB 990316 Optical Observations
  28. GRB990316, Optical observations
  29. GRB 990316 optical observations
  30. GRB990316: simultaneous optical observation
  31. ASM/IPN error box for GRB 990308 (BATSE #7457)
  32. GRB990308, Possible new SGR~0209+70
  33. GRB 990123, Field Photometry
  34. GRB 990217 Optical Observations
  35. BATSE Flight Anomaly
  36. GRB990123 observations
  37. GRB990123, Optical Observation
  38. GRB 990123: Discovery of the Probable Host Galaxy
  39. GRB19990123 observations
  40. GRB 990123: BVRI standards in the field
  41. GRB 990123: Updated Keck Spectroscopy Results
  42. GRB981220, field photometry
  43. GRB990123, Optical observation
  44. GRB990123, 15-GHz limits
  45. GRB 990123: New Constraints on Possible Foreground Galaxies
  46. GRB990123 Optical Observations
  47. GRB990123, Probability of gravitational lensing
  48. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  49. GRB990123, Preliminary Lens Search Results
  50. Search for Potential Images of GRB 990123
  51. GRB990123, Optical BVRI Observations
  52. GRB 990123: near-infrared observations.
  53. GRB990123, OSSE observations
  54. GRB990123: NIR Observation
  55. "GRB 990123: New BV Observations"
  56. GRB 990123: BATSE Observations
  57. GRB 990123: New Optical Observations, Decay Measure
  58. GRB 990123 Optical Follow-Up
  59. GRB 990123: Possible Gravitationally Lensed Burst?
  60. GRB990123, optical observation
  61. GRB 990123 optical observations
  62. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  63. GRB990123 optical observations
  64. GRB 990123 r-band photometry
  65. GRB 990123 Optical Follow-up
  66. GRB990123 Optical Observation
  67. Possible identification of SN1999E with GRB980910
  68. Optical Observations of GRB 981220
  69. GRB 981226: radio variable
  70. GRB 981226 Optical Observations
  71. GRB981226 Optical Observations
  72. GRB981226 BeppoSAX follow up
  73. GRB 981226 radio observations
  74. GRB 981226
  75. GRB 981226 optical observations
  76. radio observations of GRB 981226
  77. GRB981220 B, R and I band observations
  78. GRB 981220:Optical Observations
  79. GRB 981226 optical observations
  80. GRB 981220, radio observations
  81. GRB 981220, radio observations
  82. GRB 981220
  83. GRB 980326/Host Galaxy
  84. GRB981220 IPN error box
  85. BeppoSAX NFI Observation of GRB980425
  86. GRB980329 R,I flux calibration and R,I,K upper limits
  87. GRB980425 Optical Follow-up
  88. GRB 980923 BATSE Observations
  89. GRB980703 Very Long Baseline Interferometry
  90. GRB970508 optical observations
  91. GRB971214, association with a Galactic star?
  92. GRB980519, Optical Observations
  93. GRB980703, Host galaxy multicolor photometry
  94. GRB980703 - BeppoSAX/GRBM detection
  95. GRB 980703 (NFI observations)
  96. GRB980703 optical photometry
  97. GRB980703 optical observations
  98. GRB980703 Transient Optical Follow-Up
  99. GRB980703: LOTIS observation at early times
  100. GRB980613 Optical Observations

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