Skip to main content
New! BOOM Notices and Schema v7.0.0. See news and announcements

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"

31727 results found.

  1. VLT spectrum of GRB990510
  2. GRB 990510: Broad Band Break
  3. GRB 990510: BATSE Observations
  4. GRB990510: optical observation
  5. GRB 990510 Optical Observations
  6. GRB 990510, BVI photometry
  7. GRB 990510 optical observations
  8. GRB990510 optical observations
  9. GRB990510
  10. GRB 990510 optical observations
  11. GRB 990510 optical observations
  12. Galactic extinction towards GRB 990510
  13. IPN localization of GRB990510
  14. GRB 990506 Radio Observations
  15. GRB 990506: BATSE Observations
  16. GRB 990506, optical observations
  17. GRB 990506, Optical Observations
  18. GRB 990506 optical observations
  19. GRB 990506 optical observations
  20. GRB 990506, optical observations
  21. GRB990506 observation plan
  22. GRB 990506: Limits on the possible optical transient
  23. GRB 990506, armchair astronomy
  24. GRB 990506, optical observations from +1 to +3 hours
  25. GRB 990506, optical observations
  26. GRB990506 observation plan
  27. New IPN/RXTE error box for GRB990506
  28. IPN localization for GRB990506
  29. GRB 970228: Redshift and properties of the host galaxy
  30. GRB981220 VLBA observations
  31. GRB990321 REFINED IPN ANNULUS
  32. GRB990323 PRECISE IPN POSITION
  33. GRB 990316 Optical Observations
  34. GRB 990316, Radio observations
  35. GRB 990316, Optical observations
  36. GRB990316, Optical observations
  37. GRB 990316 optical observations
  38. GRB990316: simultaneous optical observation
  39. GRB990308 not a new SGR
  40. GRB 990308a and GRB 990308b
  41. GRB990308 (Trig. 7457), optical observations
  42. GRB981220, IPN localization
  43. GRB 981220, radio observations
  44. GRB 990123, Field Photometry
  45. GRB 990217, radio observations
  46. BATSE Resumes Normal Operations
  47. BATSE Flight Anomaly
  48. GRB990123: Caltech STIS Photometry and Images
  49. GRB990123 observations
  50. GRB990123, Optical Observation
  51. GRB 990123: Discovery of the Probable Host Galaxy
  52. GRB 990123: Reduced HST Images
  53. For Immediate Posting to GCN - HST Data GRB 990123 Available
  54. GRB19990123 observations
  55. GRB 990123: Updated Keck Spectroscopy Results
  56. GRB 990123 NOT Spectrum Update
  57. GRB990123, Optical observation
  58. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  59. GRB 990123: Publicly available reduced HST images
  60. GRB 990123: New Constraints on Possible Foreground Galaxies
  61. GRB990123 Optical Observations
  62. GRB990123, Probability of gravitational lensing
  63. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  64. GRB 990123: Continued Radio Observations
  65. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  66. On the Lensing Interpretation of GRB 990123
  67. Search for Potential Images of GRB 990123
  68. Search for Potential Images of GRB 990123
  69. GRB990123, Optical BVRI Observations
  70. GRB 990123: near-infrared observations.
  71. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  72. GRB990123: NIR Observation
  73. "GRB 990123: New BV Observations"
  74. GRB 990123 Optical Follow-Up
  75. GRB 990123; Addendum to GCN 223
  76. GRB 990123: BATSE Observations
  77. GRB 990123 Keck Spectrum update
  78. GRB990123 IPN annulus
  79. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  80. GRB990123 Optical Observations
  81. GRB 990123 Spectroscopic Redshifts
  82. GRB 990123: New Optical Observations, Decay Measure
  83. GRB 990123 Optical Follow-Up
  84. GRB 990123: Possible Gravitationally Lensed Burst?
  85. GRB990123, optical observation
  86. GRB 990123 optical observations
  87. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  88. GRB 990123 radio observations
  89. GRB 990123, new radio source
  90. GRB990123, Optical observation
  91. GRB 990123: Optical Decay Slope
  92. GRB 990123 r-band photometry
  93. GRB 990123 Optical Follow-up
  94. GRB990123, early optical counterpart detection
  95. GRB990123 Optical Observation
  96. GRB 990123: Bright New Source, Possible Optical Transient
  97. GRB 990123, Radio observations
  98. SN 1999E & GRB 980919
  99. Optical Observations of GRB 981220
  100. GRB 981226: radio variable

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov