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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.

"N/A_MC170219_R1" does not adhere to advanced search syntax. Please refer to the documentation and try again.
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"

10921 results found.

  1. GRB 260225A: SVOM/VT optical upper limits
  2. EP260126a: VLA 6 GHz detection
  3. EP260223a: Liverpool Telescope upper limits
  4. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  5. EP260223a: Xinglong optical upper limit
  6. sb26021801: SVOM/VT optical upper limits
  7. GRB 260223A: SVOM/VT optical observation
  8. EP260221a: Optical upper limit with Kinder observations
  9. EP260214b: Mondy optical observations
  10. EP260210a: Mondy optical upper limits
  11. GRB 260208A: AbAO and Terskol optical upper limits
  12. GRB 260208A: continued Mondy optical observations
  13. EP260214b: Optical upper limit with Kinder observations
  14. EP260214a: Optical upper limits with Kinder observations
  15. EP260214a: VLT near-infrared observation
  16. EP260214b: SVOM/VT optical observation
  17. EP260214b: OHP/T120 optical observations
  18. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  19. GRB 260211A: SVOM/VT optical counterpart
  20. EP260214a: SVOM/VT optical upper limits
  21. EP260213a: Optical upper limits with Kinder observations
  22. EP260213a: SVOM/VT optical upper limit
  23. EP260213a: Mondy R-band optical upper limit
  24. GRB 260211A: SVOM/VT optical observation
  25. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  26. EP260210a: Optical upper limits with Kinder observations
  27. EP260210a: SVOM/VT optical upper limit
  28. GRB 260208B: refined analysis of the EP-FXT observation
  29. GRB 260131A/B: continued Mondy optical observations
  30. GRB 260208A: Mondy optical observations
  31. GRB 260208B: EP-FXT observation
  32. GRB 260208B: SVOM/VT optical candidate
  33. GRB 260208A: SVOM/VT optical observation
  34. GRB 260208A : MASTER bright optical transient inside retracted Fermi error-box
  35. GRB 260207A : MASTER optical counterpart discovery
  36. GRB 260131A/B: Mondy and Terskol optical observations
  37. GRB 260206A (or XRB from 4U 0513-40): MAXI/GSC detection
  38. GRB 260204A: SVOM/VT confirms fading of the optical afterglow
  39. GRB 260204A: SVOM/VT optical candidate
  40. GRB 260204A : MASTER Global robotic net optical observations
  41. GRB 260131A/B: OHP/T193 optical observations
  42. EP260131a: SVOM/VT optical observation
  43. EP260131a: VLT/X-shooter spectroscopic redshift z = 0.937
  44. EP260131a: NOT early detection of the counterpart in "rapid response mode"
  45. GRB 260131B: MAXI/GSC detection
  46. GRB 260128B: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  47. GRB 260127A: INASAN-Kislovodsk, SAO RAS, and Terskol K-800 optical observations
  48. EP260128a: NOT optical counterpart candidate
  49. EP260128a: LCO optical upper limits
  50. EP260126a: SVOM/VT optical upperlimit
  51. GRB 260127A: Fermi GBM Observation
  52. GRB 260127A : MITSuME Akeno optical afterglow candidate detection
  53. Swift GRB 260127A: Global MASTER-Net observations report
  54. GRB 260127A: Swift detection of a burst
  55. EP260126a: Optical upper limit with Kinder observations
  56. EP260126a: Liverpool Telescope optical upper limits
  57. EP260126a: Further NOT optical upper limits
  58. GRB 260114A: SVOM/VT optical upper limits
  59. EP260119a: Assy AZT-20 optical observations
  60. EP260119a: Mondy and SAO RAS optical upper limits
  61. EP260119A: Mondy I-Band Observations
  62. GRB 251202A: further radio observations with the VLA
  63. EP260119a: SVOM/VT optical observation
  64. GRB 260117A: ZTSh optical upper limit
  65. GRB 260110A: SVOM detection of a burst through offline search
  66. Swift trigger on the HMXB 1A 1118-61
  67. GRB 260117A: SVOM/VT optical candidate
  68. GRB 260114A: VLT/MUSE spectroscopic observations
  69. EP260116a: Xinglong optical upper limit
  70. GRB 260114A: VLT/HAWK-I further near-infrared upper limits
  71. GRB 251222A: radio detection with the VLA
  72. GRB 260114A : MITSuME Akeno optical upper limits
  73. GRB 260114A: Mondy optical observations
  74. GRB 260114A: Swift detection of a short burst
  75. EP260110a: NOT and GTC Optical and Near-Infrared Observations
  76. GRB 251230A: Mondy Optical Observations
  77. EP260110a: SVOM/VT optical upper limits
  78. Swift Trigger 1434591: possible GRB 260109C
  79. GRB 260102A: AbAO optical observations
  80. EP260105a: SVOM/VT optical upperlimit
  81. FRB 20251229A: A potentially hyperactive repeating fast radio burst source
  82. GRB 260101A: Swift/UVOT Detection
  83. GRB 260102A: SVOM/VT optical counterpart
  84. GRB 260101A: NOT spectroscopic observations
  85. GRB 260101A: OSIRIS+ redshift z = 2.623 for the new year burst
  86. GRB 260101A: Swift detection of a burst with an optical counterpart
  87. GRB 251230A / EP251230a: SVOM/VT optical continued observations and upper limit
  88. GRB 251230A: GRANDMA/TAROT Early Detection
  89. GRB 251230A/EP251230a: Optical upper limit with Kinder observations
  90. EP251229a: Optical upper limit with Kinder observations
  91. GRB 251222A: Mondy Optical Observations
  92. GRB251230A: 7DT optical upper limits
  93. GRB 251230A / EP251230a: SVOM/VT optical observation
  94. GRB 251129A: redshift correction and SN detection at z = 0.505 with GTC
  95. GRB 251222A/EP251222b: Optical detection with Kinder observations
  96. EP251222a: Optical upper limit with Kinder observations
  97. GRB 251222A: AbAO optical observations
  98. GRB 251222A: ZTSH BVRI optical observations
  99. EP251220a: CrAO ZTSh optical observations
  100. EP251221a: PRIME upper limit

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