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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"

32419 results found.

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

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