Skip to main content
Announcing GCN Classic Migration Survey, End of Legacy Circulars Email. 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').

675 results found.

  1. GRB 100418A: GROND observations
  2. GRB 100414A: GROND Detection of the Optical Afterglow
  3. GRB 100413A: GROND Upper limits
  4. GRB100401A: GROND Upper Limits
  5. GRB 100331B: GROND Upper limits
  6. INTEGRAL trigger 5994 / GRB 100331A: GROND detection of a variable source
  7. GROND observations of GRB100316D/SN2010bh
  8. GRB 100324A: GROND observations
  9. GRB 100316D: Swift XRT enhanced position and further refined analysis
  10. GRB 100316C: GROND Detection of a Optical/NIR Afterglow Candidate
  11. GRB 100316D: GROND Detection of the Optical/NIR Afterglow Candidate
  12. GRB 100316B: GROND Detection of the Optical/NIR Afterglow Candidate
  13. GRB 100219A - Gemini South Spectroscopy
  14. GRB 100219A: VLT/X-shooter redshift
  15. GRB 100219A: GROND observations
  16. GRB 100206A: GROND upper limits
  17. GRB 100205A: GROND upper limits
  18. GRB 100103A: GROND Upper Limits
  19. GRB 091231: GROND NIR observations
  20. GRB 091230: Swift/UVOT Observations
  21. GRB 091230: Swift-XRT observation
  22. GRB 091230: GROND optical/NIR afterglow candidate
  23. GRB 091221, GROND observations
  24. GRB 091208B: GROND observations
  25. GRB 091109A: GROND confirmation of redshift z = 3.5
  26. GRB 091127: TAROT La Silla observatory optical decay
  27. GRB 091127 : GROND observations
  28. GRB 091109A: GROND and VLT observations
  29. GRB091102 : MOA optical upper limit
  30. GRB 091102: GROND Upper Limits
  31. GRB 091029: GROND Detection of the Optical/NIR Afterglow
  32. GRB 091026: GROND Upper Limits
  33. GRB 091018: GROND observations
  34. GRB 091010: Faulkes Telescope North observations
  35. GRB 091010: Enhanced XRT position
  36. GRB 091010: GROND afterglow candidate
  37. GRB 090915: GROND upper limits
  38. GRB 090904B: GROND detection of the optical afterglow
  39. GRB 090902B: VLA radio detection
  40. GRB 090902B: GROND NIR Afterglow Observations
  41. GRB 090831C: GROND upper limits
  42. GRB 090814: GROND Detection of an Optical Afterglow Candidate
  43. GRB 090812: Swift XRT refined analysis
  44. GRB 090812: GROND Observations of the Optical/NIR Afterglow
  45. GRB 090628: GROND upper limits
  46. GRB 090625B: GROND upper limits
  47. GRB 090531B: GROND observation
  48. GRB 090530: break in light curve
  49. GRB 090531: GROND upper limits
  50. GRB 090520: GROND upper limits
  51. GRB 090519: GROND observation
  52. GRB090518: GROND upper limits
  53. GRB 090516: VLT spectrum (correction & update)
  54. GRB 090516: GROND OBSERVATIONS
  55. GRB 090509 - Zadko Telescope observations
  56. GRB 090510: GROND observations
  57. GRB 090509: GROND further analysis and redshift limit
  58. GRB 090509: GROND afterglow candidate
  59. GRB 090427: GROND observations
  60. GRB 090429A: GROND upper limits
  61. GRB 090429B: GROND Observations
  62. GRB 090426: GROND Observations of the Optical/NIR Afterglow
  63. GRB 090423: GROND second epoch imaging and refined SED
  64. GRB 090424: GROND Observations of the Optical/NIR Afterglow
  65. GRB 090423: Deep z-band upper limit and confirmation of photo-z
  66. GRB 090423: GROND detection and preliminary photo-z
  67. GRB 090418B: GROND observations
  68. GRB 090419: GROND detection of afterglow candidate
  69. GRB 090410: GROND upper limits
  70. GRB 090407: GROND upper limits
  71. GRB 090404: GROND upper limits
  72. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  73. GRB 090323: UVOT Detection of Afterglow
  74. GRB 090323: GROND Detection of the Afterglow and Photo-z
  75. GRB 090313, GROND observations
  76. GRB 090309A: GROND upper limits
  77. GRB 090308: GROND observations
  78. GRB 090307: GROND Upper Limits
  79. GRB 090306B: GROND Upper Limits
  80. Radio observation of GRB 081226a with ATCA
  81. GRB 090205: GROND observations and photometric redshift estimate
  82. GRB 090118: no afterglow candidate
  83. GRB 090123: GROND detection
  84. GRB 090118: GROND Upper Limits
  85. GRB 090117: GROND Upper Limits
  86. GRB 090113: GROND Upper Limits
  87. GRB 090102: optical decay
  88. GRB 090102: GROND observations of the optical afterglow
  89. GRB 081230: GROND confirmation of the afterglow
  90. GRB 081228: GROND confirmation of the optical/NIR afterglow
  91. GRB 081228: detection by GROND
  92. GRB 081226: Gemini-South imaging
  93. GRB 081226: GROND afterglow candidate
  94. GRB 081221: GROND observations
  95. GRB 081222: Faulkes Telescope South observations
  96. GRB081222: Swift/UVOT detection of an optical afterglow
  97. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  98. Radio observation of GRB 081104 with ATCA
  99. GRB 081204: GROND Observations
  100. GRB 081121: GROND observations

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