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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"

35423 results found.

  1. ASM/IPN error box for GRB 990308 (BATSE #7457)
  2. GRB990308 not a new SGR
  3. GRB 990308a and GRB 990308b
  4. GRB990308 (Trig. 7457), optical observations
  5. GRB981220, IPN localization
  6. GRB 981220, radio observations
  7. GRB 990123, Field Photometry
  8. GRB 990217 Optical Observations
  9. GRB 990217, radio observations
  10. Optical Observations of GRB990217
  11. GRB990123: Caltech STIS Photometry and Images
  12. GRB990123 observations
  13. GRB990123, Optical Observation
  14. GRB 990123: Discovery of the Probable Host Galaxy
  15. GRB 990123: Reduced HST Images
  16. For Immediate Posting to GCN - HST Data GRB 990123 Available
  17. GRB19990123 observations
  18. GRB 990123: BVRI standards in the field
  19. GRB 990123: Updated Keck Spectroscopy Results
  20. GRB981220, field photometry
  21. GRB 990123 NOT Spectrum Update
  22. GRB990123, Optical observation
  23. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  24. GRB 990123: Publicly available reduced HST images
  25. GRB990123, Upcoming HST Service Observations
  26. GRB 990123: New Constraints on Possible Foreground Galaxies
  27. GRB990123 Optical Observations
  28. GRB990123, Probability of gravitational lensing
  29. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  30. GRB 990123: Continued Radio Observations
  31. GRB990123, Preliminary Lens Search Results
  32. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  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. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  40. "GRB 990123: New BV Observations"
  41. GRB 990123 Optical Follow-Up
  42. GRB 990123; Addendum to GCN 223
  43. GRB 990123: BATSE Observations
  44. GRB 990123 Keck Spectrum update
  45. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  46. GRB990123 Optical Observations
  47. GRB 990123 Spectroscopic Redshifts
  48. GRB 990123: New Optical Observations, Decay Measure
  49. GRB 990123 Optical Follow-Up
  50. GRB 990123: Possible Gravitationally Lensed Burst?
  51. GRB 990123 optical observations
  52. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  53. GRB 990123 radio observations
  54. GRB 990123, new radio source
  55. GRB990123, Optical observation
  56. GRB 990123: Optical Decay Slope
  57. GRB 990123 r-band photometry
  58. GRB 990123 Optical Follow-up
  59. GRB990123, early optical counterpart detection
  60. GRB990123 Optical Observation
  61. GRB 990123: Bright New Source, Possible Optical Transient
  62. GRB 990123, Radio observations
  63. SN 1999E & GRB 980919
  64. Possible identification of SN1999E with GRB980910
  65. Optical Observations of GRB 981220
  66. GRB 981226: radio variable
  67. GRB981220
  68. GRB981220, Optical Observations
  69. GRB 981220 Optical observations
  70. GRB 981226 Optical Observations
  71. GRB 980613: Spectroscopy of the host galaxy
  72. GRB981226, sub-millimeter observations
  73. GRB981220, sub-millimeter observations
  74. GRB 981220 and GRB 981226, optical observations
  75. GRB 981226 radio observations
  76. GRB 981226
  77. GRB 981226 optical observations
  78. radio observations of GRB 981226
  79. GRB981220 B, R and I band observations
  80. GRB 981220:Optical Observations
  81. GRB 981220 optical R and I observations
  82. GRB981226, BeppoSAX Christmas GRB
  83. GRB 981226 - Infrared Observations
  84. GRB 981226 optical observations
  85. GRB 981220
  86. GRB 981220, radio observations
  87. GRB981226 Optical Observation
  88. GRB 981220, radio observations
  89. GRB 981220: BeppoSAX/GRBM results
  90. GRB981220 I-band Observations
  91. GRB 981220
  92. GRB 981220 Optical Observations
  93. GRB 981220, optical observations
  94. GRB 980326/Host Galaxy
  95. GRB981220 IPN error box
  96. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  97. GRB980329 R,I flux calibration and R,I,K upper limits
  98. GRB980425: X-ray revised positions
  99. GRB 980923 BATSE Observations
  100. GRB980703 Very Long Baseline Interferometry

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