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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"

26167 results found.

  1. GRB 990506, optical observations
  2. GRB 990506, Optical Observations
  3. GRB 990506 optical observations
  4. GRB 990506, optical observations
  5. GRB 990506, armchair astronomy
  6. GRB 990506, optical observations from +1 to +3 hours
  7. GRB 990506, optical observations
  8. GRB990506 observation plan
  9. IPN localization for GRB990506
  10. GRB990323 PRECISE IPN POSITION
  11. GRB 990316 Optical Observations
  12. GRB 990316 optical observations
  13. GRB990316: simultaneous optical observation
  14. GRB990316 - Optical null results
  15. GRB990308 not a new SGR
  16. GRB 990308a and GRB 990308b
  17. GRB990308, Possible new SGR~0209+70
  18. GRB 990123, Field Photometry
  19. GRB 990217 Optical Observations
  20. BATSE Flight Anomaly
  21. GRB990217: BeppoSAX/GRBM data
  22. GRB990123 observations
  23. GRB990217 Optical observation
  24. GRB990123, Optical Observation
  25. GRB 990123: Discovery of the Probable Host Galaxy
  26. GRB 990123: Reduced HST Images
  27. GRB19990123 observations
  28. GRB 990123: BVRI standards in the field
  29. GRB981220, field photometry
  30. GRB990123, Optical observation
  31. GRB990123, 15-GHz limits
  32. GRB 990123: New Constraints on Possible Foreground Galaxies
  33. GRB990123 Optical Observations
  34. GRB990123, Probability of gravitational lensing
  35. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  36. GRB990123, Preliminary Lens Search Results
  37. On the Lensing Interpretation of GRB 990123
  38. Search for Potential Images of GRB 990123
  39. Search for Potential Images of GRB 990123
  40. GRB990123, Optical BVRI Observations
  41. GRB 990123: near-infrared observations.
  42. GRB990123, OSSE observations
  43. GRB990123: NIR Observation
  44. GRB990123, ASCA X-ray observation of afterglow
  45. "GRB 990123: New BV Observations"
  46. GRB 990123 Optical Follow-Up
  47. GRB 990123: BATSE Observations
  48. GRB990123 Optical Observations
  49. GRB 990123: New Optical Observations, Decay Measure
  50. GRB 990123 Optical Follow-Up
  51. GRB 990123: Possible Gravitationally Lensed Burst?
  52. GRB990123, optical observation
  53. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  54. GRB990123, Optical observation
  55. GRB 990123: Optical Decay Slope
  56. GRB 990123 r-band photometry
  57. GRB 990123 Optical Follow-up
  58. GRB990123, early optical counterpart detection
  59. GRB990123 Optical Observation
  60. Possible identification of SN1999E with GRB980910
  61. Optical Observations of GRB 981220
  62. GRB 981226: radio variable
  63. GRB981220
  64. GRB981220, Correction to GCN 179
  65. GRB 981220 Optical observations
  66. GRB 981226 Optical Observations
  67. GRB 981220 and GRB 981226, optical observations
  68. GRB981226 Optical Observations
  69. GRB981226 BeppoSAX follow up
  70. GRB 981226
  71. GRB 981226 optical observations
  72. GRB981220 B, R and I band observations
  73. Optical Observations of GRB981226
  74. GRB 981220:Optical Observations
  75. GRB 981226 optical observations
  76. GRB 981220
  77. GRB 981220, radio observations
  78. GRB981220 I-band Observations
  79. GRB 981220
  80. GRB 980326/Host Galaxy
  81. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  82. BeppoSAX NFI Observation of GRB980425
  83. GRB980329 R,I flux calibration and R,I,K upper limits
  84. GRB980425 Optical Follow-up
  85. GRB 980923 BATSE Observations
  86. SGR1900+14, BeppoSAX-GRBM observations
  87. GRB970508 optical observations
  88. GRB971214, association with a Galactic star?
  89. GRB980519, Optical Observations
  90. GRB980703 - BeppoSAX/GRBM detection
  91. GRB980703 optical photometry
  92. GRB 980703: BATSE Observations
  93. GRB980703 optical observations
  94. GRB980703: Radio transient
  95. GRB 980703: Spectrum of the proposed optical counterpart
  96. GRB980703 Transient Optical Follow-Up
  97. GRB980703: LOTIS observation at early times
  98. GRB980613 Optical Observations
  99. GRB980703 (I band observations)
  100. BeppoSAX NFI observations of GRB 980703

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