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ALPO Comet News for February 2019

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#1 Carl H.

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Posted 10 February 2019 - 06:58 PM

ALPO COMET NEWS FOR FEBRUARY 2019
 
2019-February-10
 
February is a short month and we are already a third of the way through it. Later than usual, here’s the ALPO Comet News for February 2019.

 

2019 is shaping up to be a slower year than 2018 for comet observers. February, on the other hand, bucks that trend with C/2018 Y1 (Iwamoto), a nicely placed comet that will peak around 6th magnitude this month.

 

Bright Comets (magnitude < 10)
   
C/2018 Y1 (Iwamoto) - The brightest comet of the month, and perhaps of 2019, is long-period comet C/2018 Y1 (Iwamoto). Masayuki Iwamoto of Awa, Tokushima, Japan discovered C/2018 Y1 on Dec 18 on CCD images obtained with a 10-cm f/4.0 Pentax SDUF II telephoto lens and Canon EOS 6D camera. This is Iwamoto's 3rd comet discovery and second of 2018 after C/2018 V1 (Machholz-Fujikawa-Iwamoto).

 

Iwamoto is s dynamically old long-period comet that last reached perihelion ~1350 years ago. With perihelion on February 6 at 1.28 au and closest approach to Earth on February 12 at 0.30 au, Iwamoto has brightened to around magnitude 6.5 and become an easy object in large binoculars and small telescopes. The comet is rapidly moving to the northwest near opposition. As a result, it is rises earlier and earlier in the evening and by mid-month is high enough to be seen at the end of dusk.

 

After close approach on the 12th, the come will fade as rapidly as it brightened. By the end of February it may be as faint as magnitude 8.5. CCD observers are reminded to watch for any interesting tail developments as we pass through the comet’s orbit plan on Feb 16/17.
 
C/2018 Y1 (Iwamoto)


T = 2019-Feb-06  q = 1.28 au   Long-Period comet - dynamically old


    Date     Mag    R.A.   Decl.     r       d    Elong  const
2019-02-01   7.7   13 03  -13 13   1.283   0.535   111    Vir
2019-02-06   7.0   12 12  -04 26   1.281   0.390   132    Vir
2019-02-11   6.4   10 37  +12 00   1.282   0.303   164    Leo
2019-02-16   6.7   08 24  +28 44   1.288   0.327   153    Cnc
2019-02-21   7.4   06 40  +34 35   1.299   0.443   125    Aur
2019-02-26   8.2   05 42  +35 15   1.314   0.599   109    Aur
2019-03-03   8.9   05 10  +34 52   1.333   0.770    97    Aur
2019-03-08   9.6   04 51  +34 23   1.356   0.944    88    Aur

 

46P/Wirtanen - The highlight of 2018, short-period comet 46P/Wirtanen is now steadily fading among the stars of Ursa Major. The fading is a result of its increasing Sun-comet (from 1.24 to 1.51 au) and Earth-comet (0.31 to 0.63 au) distances. 46P is still bright enough for most backyard observers at magnitude 9 on Feb 10. It should fade by an additional magnitude by the end of the month. Due to its far northern declination, 46P is primarily a northern hemisphere object.

 

46P/Wirtanen                                            
T = 2018-Dec-12  q = 1.06 au   Short-Period comet  Period = 5.4 yr
    Date     Mag    R.A.   Decl.     r       d    Elong  const
2019-02-01   8.2   09 24  +54 57   1.247   0.313   141    UMa
2019-02-06   8.6   09 28  +53 27   1.281   0.350   142    UMa 
2019-02-11   9.0   09 30  +51 52   1.318   0.390   142    UMa 
2019-02-16   9.3   09 32  +50 13   1.356   0.433   142    UMa
2019-02-21   9.7   09 34  +48 32   1.395   0.478   141    UMa
2019-02-26  10.1   09 36  +46 50   1.435   0.526   140    UMa
2019-03-03  10.4   09 39  +45 08   1.475   0.577   138    UMa
2019-03-08  10.8   09 41  +43 26   1.517   0.632   136    UMa

 

Faint Comets (between magnitude 10 and 13)
   
38P/Stephan-Oterma - Halley-family comet 38P/Stephan-Oterma has an orbital period of ~38 years and is making its first return since 1980. Now past perihelion (1.59 au on November 10) and closest approach to Earth (0.77 au on December 17), 38P is fading as its Sun-comet distance (1.88 to 2.13 au) and Earth-comet distance (0.97 to 1.38 au) increase. Already as faint as 11th magnitude, February may be your last chance to visually observe this comet till its next return in 2056. Similar to 46P, 38P is primarily a northern hemisphere object.

 

38P/Stephan-Oterma                                    


T = 2018-Nov-10  q = 1.59 au   Short-Period comet  Period = 38.0 yr
    Date     Mag    R.A.   Decl.     r       d    Elong  const
2019-02-01  11.2   08 28  +47 14   1.887   0.970   149    Lyn
2019-02-06  11.3   08 27  +47 27   1.920   1.017   146    Lyn
2019-02-11  11.5   08 26  +47 27   1.954   1.069   143    Lyn
2019-02-16  11.7   08 26  +47 17   1.989   1.124   140    Lyn
2019-02-21  11.9   08 27  +46 58   2.025   1.184   137    Lyn
2019-02-26  12.1   08 28  +46 31   2.062   1.248   133    Lyn
2019-03-03  12.3   08 30  +45 58   2.099   1.315   130    Lyn
2019-03-08  12.5   08 33  +45 20   2.137   1.386   127    Lyn

    
64P/Swift-Gehrels - Comet Swift-Gehrels is not an especially bright object intrinsically. This time 64P combined its best placed return with more activity than it usually displays. A ~2-3 magnitude outburst in mid-August was followed by the comet running brighter than expected for much of its apparition. Even after perihelion, 64P stayed bright. That appears to have changed as the comet entered a fading trend in January. After spending a few months around magnitude 9-10, 64P is now an 11th magnitude object and quickly fading.

 

64P/Swift-Gehrels                                       
T = 2018-Nov-03  q = 1.39 au   Short-Period comet  Period = 8.9 yr.
    Date     Mag    R.A.   Decl.     r       d    Elong  const
2019-02-01  11.0   04 10  +26 49   1.741   1.091   113    Tau
2019-02-06  11.3   04 21  +26 28   1.774   1.161   111    Tau
2019-02-11  11.6   04 32  +26 08   1.809   1.234   108    Tau
2019-02-16  11.9   04 43  +25 50   1.844   1.309   105    Tau
2019-02-21  12.2   04 53  +25 33   1.879   1.387   103    Tau
2019-02-26  12.5   05 04  +25 17   1.915   1.468   100    Tau
2019-03-03  12.9   05 14  +25 01   1.952   1.551    97    Tau
2019-03-08  13.2   05 25  +24 44   1.989   1.636    95    Tau

 

C/2016 M1 (PANSTARRS) - Not sure what is going on with this comet. Perihelion was back in August at a rather distant 2.21 au. After perihelion it faded at a very slow rate. Since November the comet has stayed around magnitude 10.5 to 11.0 which means it is not fading intrinsically. Located at far southern declinations, this is the only bright comet that is only observable from the southern hemisphere.
 
C/2016 M1 (PANSTARRS)


T = 2018-Aug-10  q = 2.21 au   Long-Period comet - dynamically old


    Date     Mag    R.A.   Decl.     r       d    Elong  const
2019-02-01  10.7   02 40  -75 19   2.957   3.105    72    Hyi
2019-02-06  10.7   02 54  -72 58   2.993   3.124    73    Hyi
2019-02-11  10.7   03 06  -70 35   3.029   3.147    74    Hyi
2019-02-16  10.7   03 17  -68 13   3.066   3.173    74    Hyi
2019-02-21  10.7   03 27  -65 50   3.102   3.203    75    Hyi
2019-02-26  10.7   03 36  -63 30   3.140   3.236    75    Ret
2019-03-03  10.7   03 45  -61 11   3.177   3.273    75    Ret
2019-03-08  10.7   03 53  -58 55   3.215   3.314    75    Ret

 

C/2018 L2 (ATLAS) - Comet ATLAS passed perihelion on 2018 December 2 at a distance of 1.71 au from the Sun. The brightness of this comet has been problematic with a large scatter of 2-3 magnitudes. The predictions below follow the reported brightness of the majority of observers so the comet may actually be somewhat brighter. Complicating things further, C/2018 L2 will be moving against the dense Milky Way star fields of Cygnus, Pegasus and Lacerta.
 
C/2018 L2 (ATLAS)


T = 2018-Dec-02  q = 1.71 au   Long-Period comet - dynamically old


    Date     Mag    R.A.   Decl.     r       d    Elong  const
2019-02-01  11.5   20 35  +29 31   1.883   2.410    47    Cyg
2019-02-06  11.7   20 52  +31 08   1.911   2.436    47    Cyg
2019-02-11  11.9   21 10  +32 42   1.940   2.467    47    Cyg
2019-02-16  12.2   21 27  +34 10   1.970   2.502    47    Cyg
2019-02-21  12.4   21 44  +35 34   2.002   2.542    46    Cyg
2019-02-26  12.7   22 02  +36 52   2.035   2.586    46    Cyg
2019-03-03  13.0   22 19  +38 05   2.070   2.633    45    Lac
2019-03-08  13.3   22 35  +39 12   2.105   2.684    45    Lac

 
Other Comets of Interest

 

(6478) Gault - On 2019 January 5, the ATLAS (Asteroid Terrestrial-Impact Last Alert System) project found Phocaea family asteroid (6478) Gault to have brightened and developed a tail. On January 26, a second tail was observed suggesting a second dust creation event. The Phocaea family is dominated by stony S-type asteroids which should be dry objects with no volatiles. There are a few carbonaceous asteroids sprinkled among the Phocaea members. Alternately, an impact it a possibility though the second event would require some extra explanation for an impact driven event. This month Gault reaches opposition around magnitude 17.5. It will be interesting to see if its tail survives the coming weeks.

 

(6478) Gault


T = 2020-Jan-02  q = 1.86 au   Phocaea Main Belt asteroid  Period = 3.5 years


    Date     Mag    R.A.   Decl.     r       d    Elong  const
2019-02-01  18.1   10 43  -12 03   2.423   1.580   140    Hya
2019-02-06  18.0   10 40  -11 33   2.413   1.534   145    Sext
2019-02-11  17.9   10 36  -10 54   2.402   1.493   150    Sext
2019-02-16  17.8   10 33  -10 05   2.392   1.458   155    Sext
2019-02-21  17.6   10 28  -09 07   2.382   1.429   159    Sext
2019-02-26  17.5   10 24  -08 02   2.371   1.407   162    Sext
2019-03-03  17.5   10 20  -06 49   2.361   1.393   163    Sext
2019-03-08  17.5   10 15  -05 31   2.350   1.385   162    Sext

 

New Discoveries

 

P/2018 V5 (Trujillo-Sheppard) - Chad Trujillo and Scott Sheppard found this 22nd magnitude comet on images taken on 2018 November 6 with the 8.2-m Subaru telescope. Not 100% sure about this, but P/2018 V5 may have been found as part of Trujillo and Sheppard’s search for for Planet X or Extreme Trans-Neptunian Objects, i.e., objects like Sedna that orbit well beyond the strong gravitational influence of Neptune. Perihelion was on 2018 October 3 at 4.71 au. Its orbital period is 26.8 years. You’ll need some big glass or lots of sub-exposures to ever get a shot at seeing this one. The two previously teamed up to discover C/2014 F3 (Sheppard-Trujillo), a Centaur comet with a 60 year period.

 

P/2019 A1 (PANSTARRS) - Short period comet P/2019 A1 (PANSTARRS) was 20th magnitude when discovered by the 1.8-m Pan-STARRS1 telescope on January 3. Perihelion was on 2018 October 11 at 2.21 au. Its orbital period is 11.6 years. P/2019 A1 will get no brighter than 20th magnitude.

 

P/2019 A2 (ATLAS) - Also a short period comet but with an orbital period of 13.7 years, P/2019 A2 (ATLAS) was found with the 0.5-m ATLAS telescope on January 4 at 18th magnitude. Perihelion was a rather distant 3.54 au on 2018 November 21. It is unlikely that P/2019 A2 will get brighter than 18th magnitude.

 

P/2019 A3 (PANSTARRS) - This object appears to be a Main Belt Comet with a very asteroidal Main Belt orbit. The object was first seen at 23rd magnitude (and inactive?) on 2018 August 8 but first noticed as cometary on images taken on January 3 at 21st magnitude. Perihelion is at 2.31 au on 2018 August 1. With a semi-major axis of 3.14 AU and eccentricity of 0.26, its aphelion (3.98 au) gets no where near Jupiter.

 

P/2019 A4 (PANSTARRS) - Yet another Main Belt Comet with a perihelion of 2.36 au, semi-major axis of 2.61 au and orbital period of 4.2 years. This one is also faint having been discovered at 20th magnitude on January 3.

 

C/2019 A5 (PANSTARRS) - Finally a new long-period comet… C/2019 A5 was found on January 4 at 20th magnitude. Its discovery was well passed its 2017 October 13 perihelion at a distant 4.54 au. The comet will not be getting any brighter though it might have been 19th magnitude nears its perihelion.

 

P/2019 A6 (Lemmon-PANSTARRS) - P/2019 A6 was first reported by observers at the Mount Lemmon Survey and Pan-STARRS as an asteroid object on 3 different nights in December. Pan-STARRS observations on January 7 found the object to be slightly diffuse. Lemmon-PANSTARRS is a short-period comet with an orbital period of 12.5 years and perihelion on 2018 August 29 at 1.94 au. It won’t get brighter than 20th magnitude.

 

P/2019 A7 (PANSTARRS) - January 2019 was a good month for Main Belt Comet discoveries. P/2019 A7 is yet another example of these objects. Discovered on January 8 at 20th magnitude, PANSTARRS reached perihelion on January 8 at 2.68 au. Its orbit has an eccentricity of 0.17, semi-major axis of 3.19 au and period of 5.7 years.

 

P/2019 A8 (PANSTARRS) - Yet another Main Belt Comet? Possibly! Found on January 11 at 21st magnitude, this object passed perihelion on 2018 August 26 at 1.85 au. It has a moderately large eccentricity of 0.41 but that only brings it to an aphelion of 4.45 au. Not impossible that it is a more typical Jupiter family comet with a low aphelion, but another Main Belt Comet is also possible. While it has the semi-major axis and inclination (3 deg) of a Themis family object, its eccentricity is much too high to be considered a member of that family.

 

C/2019 A9 (PANSTARRS) - Pan-STARRS found this dynamically old long-period comet on January 14 at 20th magnitude. When it reaches perihelion on 2019 July 26 at 1.43 au it may be as bright as 16th magnitude.

 

C/2019 B1 (Africano) - Brian Africano found this 17th magnitude dynamically old long-period comet on January 19 with the Catalina 0.68-m schmidt telescope. The comet is likely as bright as it’ll get as it approaches a 2019 March 19 perihelion at 1.60 au.

 

P/2019 B2 (Groeller) - Another Catalina 0.68-m schmidt discovery, P/2019 B2 was found on January 26 at 17th magnitude. Perihelion will be on 2019 June 8 at 2.42 au on its 7.6 year orbit.

 

 

As always, the Comet Section is happy to receive all comet observations, whether images, drawings, magnitude estimates, and even spectra. Please send your observations via email to < carl.hergenrother @ alpo-astronomy.org >.
- Carl Hergenrother (ALPO Comet Section Coordinator)


  • roelb and mbrio76 like this

#2 Special Ed

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Posted 11 February 2019 - 10:35 AM

Thanks, Carl!



#3 Rich (RLTYS)

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Posted 23 February 2019 - 03:37 PM

Thanks for the info.waytogo.gif

 

Rich (RLTYS)




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