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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"

24663 results found.

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

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