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"

36135 results found.

  1. GRB 030329: SARA Optical Observations
  2. GRB 030324, optical search
  3. GRB030329 - near contemporaneous optical limits from CONCAM
  4. GRB 030329, optical observations
  5. GRB 030329: Light curve observed during the change of its slope.
  6. GRB030329, BVRcIc field photometry
  7. GRB030329, SPM optical observations
  8. GRB 030329: Optical Decay
  9. Redshift of GRB 030329
  10. GRB030329: ROTSE network observes steepening of decay curve
  11. GRB 030329, optical photometry
  12. GRB 030329: Optical decay and synthesis
  13. GRB 030329: Radio Observations
  14. GRB 030329, optical spectroscopy
  15. GRB 030329: still bright
  16. GRB 030329: Optical pre-Imaging
  17. GRB 030329: visual observations
  18. GRB 030329: Upper limit from 5.6 hours before trigger
  19. GRB030328: R optical observation
  20. GRB 030323: Gemini South VRI obsevations.
  21. GRB030329: Optical observations
  22. GRB 030329, R-band observations, supplement
  23. GRB030329:optical observations by MASTER
  24. GRB 030329: optical observations
  25. GRB 030329, R-band observations
  26. GRB 030329: OT B and R photometry, decline rate
  27. GRB030329: Upper limits from recent and historical observations.
  28. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  29. RXTE detection of GRB 030329 afterglow
  30. GRB 030329: Optical Afterglow Observations
  31. GRB 030329: precise position from Kyoto images
  32. GRB 030328 Optical Observations
  33. GRB 030328: Optical observations
  34. GRB 030328: optical observations
  35. GRB 030329: Optical afterglow fading
  36. GRB 030329 follow-up
  37. GRB 030329: Optical afterglow candidate
  38. GRB 030329: OT candidate
  39. GRB 030329: Optical afterglow candidate
  40. GRB 030328: OT photometry
  41. VLT spectra of GRB 030328
  42. GRB 030328, optical spectroscopy
  43. GRB 030328, optical observations
  44. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  45. GRB 030328: Optical observations
  46. Re: GRB 030328: Finding chart
  47. GRB 030328: Finding chart
  48. GRB 030328: Optical afterglow candidate
  49. GRB030131, BVRcIc field photometry
  50. Possible GRB030323 localized by INTEGRAL
  51. IPN triangulation of GRB030325 (final analysis)
  52. IPN triangulation of GRB030326 (single small error box)
  53. GRB 030323: SARA Optical Observations
  54. IPN triangulation of GRB030325 (single small error box)
  55. GRB030324, optical observations
  56. IPN triangulation of GRB030325 (two small error boxes)
  57. GRB 030324: TAROT optical observations
  58. GRB 030324 (HETE #2641): Optical observations
  59. GRB030324, Optical Observations
  60. GRB030323: Upper limits from recent and historical observations.
  61. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  62. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  63. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  64. VLT/FORS2 spectra of GRB 030323
  65. GRB030323, ROTSE-III detection of possible optical counterpart
  66. GRB030323, optical observations
  67. GRB030324, BVRcIc field photometry
  68. GRB030323, possible optical counterpart
  69. GRB030323, BVRcIc field calibration
  70. GRB 030324 optical observations
  71. GRB 030320: Optical Observations
  72. GRB 030324, optical observations
  73. IPN triangulation of GRB030320B (annulus)
  74. IPN triangulation of GRB030320 (small error box)
  75. IPN triangulation of GRB030320
  76. Possible GRB 030320 localized by INTEGRAL
  77. IPN upper limit to a GRB associated with SN2003L
  78. IPN triangulation of GRB030317 (annulus)
  79. IPN triangulation of GRB030307 (annulus)
  80. GRB 030227: Optical limit at RIKEN
  81. GRB 030226 Optical observations
  82. IPN triangulation of GRB030306 (single small error box - REVISED)
  83. GRB030226: Optical observations at Asiago
  84. IPN triangulation of GRB030306 (single small error box)
  85. IPN triangulation of GRB030306 (two small error boxes)
  86. IPN triangulation of GRB030306 (intense; annulus only so far)
  87. GRB 030226: Optical observations
  88. IPN triangulation of GRB030304 (annulus)
  89. GRB 030227: Optical observations
  90. GRB030226, BVRc observations
  91. Chandra detection of the X-ray afterglow of GRB 030226
  92. GRB 030226, further optical/NIR imaging
  93. GRB030227, optical observations
  94. GRB 030226: Ic Observations
  95. GRB030227: Kiso optical upper limit
  96. IPN triangulation of GRB030301 (annulus)
  97. IPN triangulation of GRB030228 (annulus)
  98. GRB030227, BVRcIc field photometry
  99. GRB030226, BVRcIc field calibration
  100. GRB 030227 optical afterglow

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