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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"
  1. GRB990123, Optical observation
  2. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  3. GRB 990123: Publicly available reduced HST images
  4. GRB990123, Upcoming HST Service Observations
  5. GRB990123, 15-GHz limits
  6. GRB 990123: New Constraints on Possible Foreground Galaxies
  7. GRB990123 Optical Observations
  8. GRB990123, Probability of gravitational lensing
  9. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  10. GRB 990123: Continued Radio Observations
  11. GRB990123, Preliminary Lens Search Results
  12. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  13. On the Lensing Interpretation of GRB 990123
  14. Search for Potential Images of GRB 990123
  15. Search for Potential Images of GRB 990123
  16. GRB990123, Optical BVRI Observations
  17. GRB 990123: near-infrared observations.
  18. GRB990123, OSSE observations
  19. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  20. GRB990123: NIR Observation
  21. GRB990123, ASCA X-ray observation of afterglow
  22. "GRB 990123: New BV Observations"
  23. GRB 990123 Optical Follow-Up
  24. GRB 990123; Addendum to GCN 223
  25. GRB 990123: BATSE Observations
  26. GRB 990123 Keck Spectrum update
  27. GRB990123 IPN annulus
  28. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  29. GRB990123 Optical Observations
  30. GRB 990123 Spectroscopic Redshifts
  31. GRB 990123: New Optical Observations, Decay Measure
  32. GRB 990123 Optical Follow-Up
  33. GRB 990123: Possible Gravitationally Lensed Burst?
  34. GRB990123, optical observation
  35. GRB 990123 optical observations
  36. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  37. GRB 990123 radio observations
  38. GRB 990123, new radio source
  39. GRB990123 optical observations
  40. GRB990123, Optical observation
  41. GRB 990123: Optical Decay Slope
  42. GRB 990123 r-band photometry
  43. GRB 990123 Optical Follow-up
  44. GRB990123, early optical counterpart detection
  45. GRB990123 Optical Observation
  46. GRB990123, BeppoSAX-NFI X-ray afterglow detection
  47. GRB990123, refined SAX-WFC position
  48. GRB 990123: Bright New Source, Possible Optical Transient
  49. GRB 990123, Radio observations
  50. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  51. SN 1999E & GRB 980919
  52. Possible identification of SN1999E with GRB980910
  53. Optical Observations of GRB 981220
  54. GRB 981226: radio variable
  55. GRB981220
  56. GRB981220, Correction to GCN 179
  57. GRB981220, Optical Observations
  58. GRB 981220 Optical observations
  59. GRB 981226 Optical Observations
  60. GRB 980613: Spectroscopy of the host galaxy
  61. GRB981226, sub-millimeter observations
  62. GRB981220, sub-millimeter observations
  63. GRB 981220 and GRB 981226, optical observations
  64. GRB981226 Optical Observations
  65. GRB981226 BeppoSAX follow up
  66. GRB 981226 radio observations
  67. GRB 981226
  68. GRB 981226 optical observations
  69. radio observations of GRB 981226
  70. GRB981220 B, R and I band observations
  71. GRB981226, BeppoSAX-NFI follow-up
  72. Optical Observations of GRB981226
  73. GRB 981220:Optical Observations
  74. GRB 981220 optical R and I observations
  75. GRB981226, BeppoSAX Christmas GRB
  76. GRB 981226 - Infrared Observations
  77. GRB 981226 optical observations
  78. GRB 981220
  79. GRB 981220, radio observations
  80. GRB981226 Optical Observation
  81. GRB 981220, radio observations
  82. GRB 981220: BeppoSAX/GRBM results
  83. GRB981220 I-band Observations
  84. GRB981220 Optical Observations
  85. GRB 981220
  86. GRB 981220 Optical Observations
  87. GRB 981220, optical observations
  88. GRB 980326/Host Galaxy
  89. GRB981220 IPN error box
  90. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  91. BeppoSAX NFI Observation of GRB980425
  92. GRB980329 R,I flux calibration and R,I,K upper limits
  93. GRB980425 Optical Follow-up
  94. GRB980425: X-ray revised positions
  95. GRB 980923 BATSE Observations
  96. SGR1900+14, BeppoSAX-GRBM observations
  97. GRB980703 Very Long Baseline Interferometry
  98. GRB970508 optical observations
  99. GRB971214, association with a Galactic star?
  100. Optical Observations of the Host Galaxy of GRB 980519

Advanced

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