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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"

21658 results found.

  1. GRB 990123, optical monitoring
  2. GRB 990506, optical observations
  3. GRB 990510: Final BeppoSAX-WFC Coordinates
  4. GRB 990506, Optical Observations
  5. GRB 990506 optical observations
  6. GRB 990506, optical observations
  7. GRB 990506, optical observations from +1 to +3 hours
  8. GRB 990506, optical observations
  9. GRB990506 observation plan
  10. IPN localization for GRB990506
  11. GRB 970228: Redshift and properties of the host galaxy
  12. GRB 990316 Optical Observations
  13. GRB 990316, Radio observations
  14. GRB 990316 optical observations
  15. GRB990316: simultaneous optical observation
  16. ASM/IPN error box for GRB 990308 (BATSE #7457)
  17. GRB990308 (Trig. 7457), optical observations
  18. GRB981220, IPN localization
  19. GRB 990123, Field Photometry
  20. GRB 990217 Optical Observations
  21. GRB 990217, radio observations
  22. BATSE Flight Anomaly
  23. GRB990123 observations
  24. GRB990217, WFC position
  25. GRB990123, Optical Observation
  26. GRB 990123: Discovery of the Probable Host Galaxy
  27. GRB19990123 observations
  28. GRB 990123: BVRI standards in the field
  29. GRB981220, field photometry
  30. GRB990123, Optical observation
  31. GRB990123, Upcoming HST Service Observations
  32. GRB990123, 15-GHz limits
  33. GRB 990123: New Constraints on Possible Foreground Galaxies
  34. GRB990123 Optical Observations
  35. GRB990123, Probability of gravitational lensing
  36. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  37. GRB990123, Preliminary Lens Search Results
  38. On the Lensing Interpretation 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. "GRB 990123: New BV Observations"
  45. GRB990123 IPN annulus
  46. GRB 990123 Spectroscopic Redshifts
  47. GRB 990123: New Optical Observations, Decay Measure
  48. GRB 990123 Optical Follow-Up
  49. GRB 990123: Possible Gravitationally Lensed Burst?
  50. GRB990123, optical observation
  51. GRB 990123 optical observations
  52. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  53. GRB 990123 radio observations
  54. GRB 990123: Optical Decay Slope
  55. GRB 990123 r-band photometry
  56. GRB 990123 Optical Follow-up
  57. GRB990123, early optical counterpart detection
  58. GRB990123 Optical Observation
  59. Possible identification of SN1999E with GRB980910
  60. Optical Observations of GRB 981220
  61. GRB 981226: radio variable
  62. GRB981220, Optical Observations
  63. GRB 981226 Optical Observations
  64. GRB981226 Optical Observations
  65. GRB981226 BeppoSAX follow up
  66. GRB 981226
  67. GRB 981226 optical observations
  68. GRB981220 B, R and I band observations
  69. Optical Observations of GRB981226
  70. GRB 981220:Optical Observations
  71. GRB 981226 - Infrared Observations
  72. GRB 981226 optical observations
  73. GRB 981220, radio observations
  74. GRB 981220
  75. GRB 980326/Host Galaxy
  76. GRB981220 IPN error box
  77. BeppoSAX NFI Observation of GRB980425
  78. GRB980329 R,I flux calibration and R,I,K upper limits
  79. GRB980425 Optical Follow-up
  80. GRB980425: X-ray revised positions
  81. GRB 980923 BATSE Observations
  82. GRB970508 optical observations
  83. GRB971214, association with a Galactic star?
  84. GRB980519, Optical Observations
  85. GRB980703 - BeppoSAX/GRBM detection
  86. GRB 980703 (NFI observations)
  87. GRB980703 optical photometry
  88. GRB980703 optical observations
  89. GRB980703: Radio transient
  90. RXTE Observation of GRB 980706
  91. GRB980703 Transient Optical Follow-Up
  92. GRB980703: LOTIS observation at early times
  93. GRB980613 Optical Observations
  94. GRB 980703
  95. BeppoSAX NFI observations of GRB 980703
  96. GRB980703 optical followup
  97. Radio observations of SGRs
  98. SGR1900+14 field optical observations
  99. GRB 980613 Near-IR observations
  100. GRB 980613: Optical transient and its host galaxy

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