Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

37512 results found.

  1. GRB990123: Caltech STIS Photometry and Images
  2. GRB990123 observations
  3. GRB990123, Optical Observation
  4. GRB 990123: Discovery of the Probable Host Galaxy
  5. GRB 990123: Reduced HST Images
  6. For Immediate Posting to GCN - HST Data GRB 990123 Available
  7. GRB19990123 observations
  8. GRB 990123: BVRI standards in the field
  9. GRB 990123: Updated Keck Spectroscopy Results
  10. GRB981220, field photometry
  11. GRB 990123 NOT Spectrum Update
  12. GRB990123, Optical observation
  13. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  14. GRB 990123: Publicly available reduced HST images
  15. GRB990123, Upcoming HST Service Observations
  16. GRB 990123: New Constraints on Possible Foreground Galaxies
  17. GRB990123 Optical Observations
  18. GRB990123, Probability of gravitational lensing
  19. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  20. GRB 990123: Continued Radio Observations
  21. GRB990123, Preliminary Lens Search Results
  22. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  23. On the Lensing Interpretation of GRB 990123
  24. Search for Potential Images of GRB 990123
  25. Search for Potential Images of GRB 990123
  26. GRB990123, Optical BVRI Observations
  27. GRB 990123: near-infrared observations.
  28. GRB990123, OSSE observations
  29. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  30. "GRB 990123: New BV Observations"
  31. GRB 990123 Optical Follow-Up
  32. GRB 990123; Addendum to GCN 223
  33. GRB 990123: BATSE Observations
  34. GRB 990123 Keck Spectrum update
  35. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  36. GRB990123 Optical Observations
  37. GRB 990123 Spectroscopic Redshifts
  38. GRB 990123: New Optical Observations, Decay Measure
  39. GRB 990123 Optical Follow-Up
  40. GRB 990123: Possible Gravitationally Lensed Burst?
  41. GRB 990123 optical observations
  42. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  43. GRB 990123 radio observations
  44. GRB 990123, new radio source
  45. GRB990123, Optical observation
  46. GRB 990123: Optical Decay Slope
  47. GRB 990123 r-band photometry
  48. GRB 990123 Optical Follow-up
  49. GRB990123, early optical counterpart detection
  50. GRB990123 Optical Observation
  51. GRB 990123: Bright New Source, Possible Optical Transient
  52. GRB 990123, Radio observations
  53. SN 1999E & GRB 980919
  54. Possible identification of SN1999E with GRB980910
  55. Optical Observations of GRB 981220
  56. GRB 981226: radio variable
  57. GRB981220
  58. GRB981220, Optical Observations
  59. GRB 981220 Optical observations
  60. GRB 981226 Optical Observations
  61. GRB 980613: Spectroscopy of the host galaxy
  62. GRB981226, sub-millimeter observations
  63. GRB981220, sub-millimeter observations
  64. GRB 981220 and GRB 981226, optical observations
  65. GRB 981226 radio observations
  66. GRB 981226
  67. GRB 981226 optical observations
  68. radio observations of GRB 981226
  69. GRB981220 B, R and I band observations
  70. GRB 981220:Optical Observations
  71. GRB 981220 optical R and I observations
  72. GRB981226, BeppoSAX Christmas GRB
  73. GRB 981226 - Infrared Observations
  74. GRB 981226 optical observations
  75. GRB 981220
  76. GRB 981220, radio observations
  77. GRB981226 Optical Observation
  78. GRB 981220, radio observations
  79. GRB 981220: BeppoSAX/GRBM results
  80. GRB981220 I-band Observations
  81. GRB 981220
  82. GRB 981220 Optical Observations
  83. GRB 981220, optical observations
  84. GRB 980326/Host Galaxy
  85. GRB981220 IPN error box
  86. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  87. GRB980329 R,I flux calibration and R,I,K upper limits
  88. GRB980425: X-ray revised positions
  89. GRB 980923 BATSE Observations
  90. GRB980703 Very Long Baseline Interferometry
  91. GRB970508 optical observations
  92. GRB971214, association with a Galactic star?
  93. Optical Observations of the Host Galaxy of GRB 980519
  94. GRB980519, Optical Observations
  95. GRB980703, Host galaxy multicolor photometry
  96. GRB980703 - BeppoSAX/GRBM detection
  97. GRB 980703 (NFI observations)
  98. GRB980703 optical photometry
  99. GRB 980703: BATSE Observations
  100. GRB980703: Radio transient

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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